This tiny, cylindrical gearmotor consists of a coreless brushed DC motor and a 136:1 plastic planetary gearbox. The entire assembly has a diameter of just 6 mm (0.24″) and an extremely light weight of 1.25 g (0.044 oz), making it a great actuator for miniature robots and very small mechanisms.Key specs at 6 V: 500 RPM and 45 mA free-run, 8 oz-in (0.6 kg-cm) and 400 mA stall.

26:1 sub-micro plastic planetary gearmotor next to a micro metal gearmotor and a LEGO Minifigure for size reference.

Sub-micro plastic planetary gearmotors. Gear ratios from top to bottom: 700:1, 136:1, 26:1.

These tiny brushed DC gearmotors have a diameter of just 6 mm and weigh just over a gram, which makes them great actuators for miniature robots and very small mechanisms. They consist of a coreless motor fastened to a planetary gearbox by a small clip. The gears are made from liquid crystal polymers (LCPs), and gearbox’s nylon output shaft is compatible with our 14 mm wheels. Three gear ratios are available:

26:1, which has a free run speed of 2500 RPM and stall torque of 1.5 oz-in (110 g-cm) at 6 V

136:1, which has a free run speed of 500 RPM and stall torque of 8 oz-in (550 g-cm) at 6 V

700:1, which has a free run speed of 90 RPM and stall torque of 12 oz-in (900 g-cm) at 6 V

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. For these gearboxes, the recommended upper limit for instantaneous torque is 3.5 oz-in (250 g-cm); we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

The intended nominal operating voltage for these motors is 3 V to 6 V, though in general, these kinds of motors can be used at voltages outside this range (rotation typically starts between 0.2 V and 0.3 V). Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor. When operating at 3 V, the free-run speed, stall torque, and stall current will all be approximately half of what they are at 6 V as these specifications scale roughly linearly with voltage.

Since the gearmotor’s output shaft is nylon, there can be small variances in the diameter from unit to unit. These variations might cause press-fit attachments like our 14 mm wheel to fit loosely in some instances. If you experience a loose fit, you could try swapping wheels or using a small dab of glue to help hold the wheel on.

The following diagram shows the micro plastic gearmotor dimensions in mm. The planetary gearbox has a D-shaped plastic output shaft, which is 2 mm in diameter with a section that is flattened by 0.5 mm. The “D” portion of the shaft is 2.5 mm long. The motor measures 6 mm in diameter and 9.3 mm in length, and the gearbox length, labeled “L” in the diagram below, depends on the gear ratio.

Dimensions of the Sub-Micro Plastic Planetary Gearmotors. Units are mm over [inches].

This dimension diagram is also available as a downloadable PDF (92k pdf).

These motors originally shipped with leads that extended approximately 2 cm (0.8″) from the back of the motor, but we began transitioning to shipping units with much longer leads (approximately 12.5 cm, or 5″) in January, 2017. These leads are pre-stripped and unterminated (i.e. they do not end in a connector).

The micro plastic gearmotor’s output shaft is compatible with our 14 mm wheels. We do not have any brackets for this gearmotor, and it does not have any mounting holes, but its compact size makes it easy to fasten with tape or glue. Alternatively, since this gearmotor is nearly the same size as a 1/4″ fuse, it can be mounted using standard 1/4″ (6 mm) fuse clips, which can be found at places like Radio Shack and Digi-Key.

Sub-micro plastic planetary gearmotor with a 14×4.5mm wheel.

26:1 sub-micro plastic planetary gearmotor being held by a 1/4″ (6 mm) fuse clip.

People often buy this product together with:

This gearmotor consists of a low-power, 6 V brushed DC motor combined with a 98.78:1 metal spur gearbox, and it has an integrated 48 CPR quadrature encoder on the motor shaft, which provides 4741.44 counts per revolution of the gearbox’s output shaft. The gearmotor is cylindrical, with a diameter just under 25 mm, and the D-shaped output shaft is 4 mm in diameter and extends 12.5 mm from the face plate of the gearbox.Key specs at 6 V: 58 RPM and 250 mA free-run, 130 oz-in (9.4 kg-cm) and 2.4 A stall.

These cylindrical brushed DC gearmotors are available in a wide range of gear ratios and with five different motors (two power levels of 6V motors and three power levels of 12V motors). The gearmotors all have the same 25 mm diameter case and 4 mm diameter gearbox output shaft, so it is generally easy to swap one version for another if your design requirements change (though the length of the gearbox tends to increase with the gear ratio). All versions are also available with an integrated 48 CPR quadrature encoder on the motor shaft. Please see the 25D metal gearmotor comparison table for detailed specifications of all our 25D metal gearmotors. This dynamically-sortable table can help you find the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below:

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. For these gearboxes, the recommended upper limit for instantaneous torque is 200 oz-in (15 kg-cm); we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of a second) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Exact gear ratio: ``(22×22×22×22×22×23) / (12×10×10×10×10×10) ~~bb(98.78:1)``

The diagram below shows the dimensions of the 25D mm line of gearmotors (units are mm over [inches]). This diagram is also available as a downloadable PDF (223k pdf).

Dimensions of the Pololu 25D mm metal gearmotors. Units are mm over [inches].

The face plate has two mounting holes threaded for M3 screws. You can use our custom-designed 25D mm metal gearmotor bracket (shown in the picture below) to mount the gearmotor to your project via these mounting holes and the screws that come with the bracket.

Pololu 25D mm metal gearmotor bracket pair.

Pololu 25D mm gearmotor with bracket.

The 4 mm diameter gearbox output shaft works with Pololu universal aluminum mounting hub for 4mm shafts, which can be used to mount our larger Pololu wheels (60mm-, 70mm-, 80mm-, and 90mm-diameter) or custom wheels and mechanisms to the gearmotor’s output shaft as shown in the left picture below. Alternatively, you could use our 4mm scooter wheel adapter to mount many common scooter, skateboard, and inline skate wheels to the gearmotor’s output shaft as shown in the right picture below.

Pololu 60×8mm wheel on a Pololu 25D mm metal gearmotor.

A 25D mm gearmotor connected to a scooter wheel by the 4 mm scooter wheel adapter.

These are the same type of motors used in the Wild Thumper all-terrain chassis, so the gearbox’s output shaft also works directly with the hex adapters included with the 120mm-diameter Wild Thumper wheels (the left picture below shows a 25D mm gearmotor while the right picture shows the smaller 20D mm gearmotor):

Dagu Wild Thumper wheel 120×60mm (chrome) with Pololu 25D mm metal gearmotor.

Dagu Wild Thumper wheel 120×60mm (metallic red) with Pololu 20D mm metal gearmotor.

12mm Hex Wheel Adapter for 4mm Shaft on a 20D mm Metal Gearmotor.

We have a number of motor controllers and motor drivers that work with these 25D mm metal gearmotors. For the LP and MP versions, we recommend our MC33296-based motor drivers, for which we have basic single and dual carriers and a dual-channel shield for Arduino. For the HP versions, we recommend our VNH5019-based motor drivers (available as single and dual carriers), though these can also be a good choice for the lower-power motors because they will run much cooler than the MC33926 carriers. If you are looking for higher-level control interfaces, such as USB, RC, analog voltages, or TTL serial, consider our Simple Motor Controllers, Jrk motor controllers, or TReX motor controllers; these controllers are available in various power levels, and the appropriate one depends on the particular version of 25D mm motor you have (we generally recommend a motor controller that can handle continuous currents above the stall current of your motor).

Pololu dual VNH5019 motor driver shield for Arduino.

Pololu TReX Dual Motor Controller.

Simple Motor Controller 18v7, fully assembled.

We have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

25D mm metal gearmotor with 48 CPR encoder: close-up view of encoder.

The versions of these gearmotors with encoders use a A two-channel Hall effect sensor to detect the rotation of a magnetic disk on a rear protrusion of the motor shaft. The quadrature encoder provides a resolution of 48 counts per revolution of the motor shaft when counting both edges of both channels. To compute the counts per revolution of the gearbox output, multiply the gear ratio by 48. The motor/encoder has six color-coded, 8″ (20 cm) leads terminated by a 1×6 female header with a 0.1″ pitch, as shown in the main product picture. This header works with standard 0.1″ male headers and our male jumper and precrimped wires. If this header is not convenient for your application, you can pull the crimped wires out of the header or cut the header off. The following table describes the wire functions:

The Hall sensor requires an input voltage, Vcc, between 3.5 and 20 V and draws a maximum of 10 mA. The A and B outputs are square waves from 0 V to Vcc approximately 90° out of phase. The frequency of the transitions tells you the speed of the motor, and the order of the transitions tells you the direction. The following oscilloscope capture shows the A and B (yellow and white) encoder outputs using a motor voltage of 6 V and a Hall sensor Vcc of 5 V:

Encoder A and B outputs for 25D mm HP 6V metal gearmotor with 48 CPR encoder (motor running at 6 V).

By counting both the rising and falling edges of both the A and B outputs, it is possible to get 48 counts per revolution of the motor shaft. Using just a single edge of one channel results in 12 counts per revolution of the motor shaft, so the frequency of the A output in the above oscilloscope capture is 12 times the motor rotation frequency.

We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.

Some of the Pololu metal gearmotors.

People often buy this product together with:

This 200:1 gearbox with brushed DC motor has a low-current motor and provides power and speed that is comparable to an RC servo at a fraction of the cost. At 6 V, it has a free-run speed of 51 RPM and a stall torque of approximately 100 oz-in. Though the product picture shows two gearmotors, this product is for a single motor.

Pololu plastic gearmotor 90 deg. output with opened gearbox.

This 200:1 plastic gearmotor (gearbox with brushed DC motor) is a great low-cost alternative to modified hobby servos or Tamiya gearboxes. The low-current motor is a perfect match for our qik 2s9v1 dual serial motor controller, Baby Orangutan robot controller, or DRV8833 dual motor driver carrier, and the compact size makes this unit an attractive choice for small robot designs. The recommended operating voltage range for this motor is 3 – 12 V.

This is a higher-torque, lower-speed version of the 120:1 plastic gearmotor 90-degree output. At 6 V, the gearbox and motor provide approximately 100 oz-in of torque and 51 RPM. The free-running current is 70 mA, and the stall current is 800 mA. The gearbox is protected by a built-in safety clutch that will typically slip before gear teeth can shear.

This gearmotor comes pre-assembled, with the gears fully enclosed, and the output shaft is 6 mm long and 7 mm in diameter with two sides flattened. The output shaft is at a 90° angle from the axis of the motor shaft; we also sell a similar gearmotor with an offset output shaft.

There are two built-in mounting holes that work with our stamped aluminum L-bracket and extended stamped aluminum L-bracket, as shown in the pictures below:

Plastic gearmotor with 90-degree output (item #1120 or #1121) mounted with Pololu stamped aluminum L-bracket.

Plastic gearmotor with 90-degree output (item #1120 or #1121) mounted with Pololu extended stamped aluminum L-bracket.

A custom-molded GMPW plastic wheel for this gearmotor is available in a variety of colors.

Dimensions (in mm) of the 120:1 and 200:1 plastic gearmotors with 90-degree outputs.

You can download a pdf version of this drawing here (104k pdf).

People often buy this product together with:

This gearmotor is a miniature low-power, 6 V brushed DC motor with a 9.96:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.Key specs at 6 V: 1300 RPM and 40 mA with no load, 2 oz-in (0.2 kg-cm) and 0.36 A at stall.

These tiny brushed DC gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with five different motors: high-power 6 V and 12 V motors with long-life carbon brushes (HPCB), and high-power (HP), medium power (MP), and low power (LP) 6 V motors with shorter-life precious metal brushes. The 6 V and 12 V HPCB motors offer the same performance at their respective nominal voltages, just with the 12 V motor drawing half the current of the 6 V motor. The 6 V HPCB and 6 V HP motors are identical except for their brushes, which only affect the lifetime of the motor.

The HPCB versions (shown on the left in the picture below) can be differentiated from versions with precious metal brushes (shown on the right) by their copper-colored terminals. Note that the HPCB terminals are 0.5 mm wider than those on the other micro metal gearmotor versions (2 mm vs. 1.5 mm), and they are about 1 mm closer together (6 mm vs. 7 mm).

Versions of these gearmotors are also available with an additional 1 mm-diameter output shaft that protrudes from the rear of the motor. This 4.5 mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our magnetic encoder for micro metal gearmotors (see the picture on the right), to provide motor speed or position feedback.

With the exception of the 1000:1 gear ratio versions, all of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change.

Please see the micro metal gearmotor datasheet (2MB pdf) for more information, including detailed performance graphs for each micro metal gearmotor version. You can also use our dynamically sortable micro metal gearmotor comparison table for search for the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below.

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. The recommended upper limit for instantaneous torque is 35 oz-in (2.5 kg-cm) for the 1000:1 gearboxes and 25 oz-in (2 kg*cm) for all the other gear ratios; we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP and HPCB) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Exact gear ratio: ``(35×37) / (13×10) ~~ bb(9.96:1)``

In terms of size, these gearmotors are very similar to Sanyo’s popular 12 mm NA4S DC gearmotors, and gearmotors with this form factor are occasionally referred to as N20 motors. The versions with carbon brushes (HPCB) have slightly different terminal and end-cap dimensions than the versions with precious metal brushes, but all of the other dimensions are identical.

Dimensions of versions with carbon brushes (HPCB)

Dimensions of the Pololu micro metal gearmotors with carbon brushes (HPCB). Units are mm over [inches].

Dimensions of versions with precious metal brushes (LP, MP, and HP)

Dimensions of the Pololu micro metal gearmotors with precious metal brushes: low-power (LP), medium-power (MP), and high-power (HP). Units are mm over [inches].

These diagrams are also available as a downloadable PDF (262k pdf).

Wheels and hubs: The micro metal gearmotor’s output shaft matches our assortment of Pololu wheels and the Solarbotics RW2i rubber wheel. You can also use our Pololu universal mounting hubs to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft, and you can use our 12mm hex wheel adapter to use this motor with many common hobby RC wheels.

Pololu wheel 32×7mm on a micro metal gearmotor.

Black Pololu 70×8mm wheel on a Pololu micro metal gearmotor.

A pair of Pololu universal aluminum mounting hubs for 3 mm diameter shafts.

12mm Hex Wheel Adapter for 3mm Shaft on a Micro Metal Gearmotor.

Mounting brackets: Our mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm. Our micro metal gearmotors will also work with our 15.5D mm metal gearmotor bracket pair.

Black micro metal gearmotor mounting bracket pair with included screws and nuts.

White micro metal gearmotor mounting bracket pair with included screws and nuts.

Pololu micro metal gearmotor bracket extended with micro metal gearmotor.

Quadrature encoders: We offer several quadrature encoders that work with our micro metal gearmotors.

Magnetic Encoder Kit for Micro Metal Gearmotors assembled with ribbon cable wires.

Example of an installed micro metal gearmotor reflective optical encoder.

Note: The HPCB versions of our micro metal gearmotors are not compatible with our #2590 and #2591 optical encoders or our older #2598 magnetic encoders (the terminals are too wide to fit through the corresponding holes in the encoder boards). However, they are compatible with our newer #3081 magnetic encoders.

Motor controllers and drivers: We have a number of motor controllers, motor drivers, and robot controllers that make it easy to drive these micro metal gearmotors. For the 6 V micro metal gearmotors, consider the DRV8838 single-channel motor driver carrier, the DRV8833 dual motor driver carrier, and DRV8835 dual motor driver carrier (or DRV8835 shield for Arduino). For the 12 V micro metal gearmotors, consider the MAX14870 single-channel motor driver carrier, DRV8801 single-channel motor driver carrier, and A4990 dual motor driver carrier (or A4990 shield for Arduino).

DRV8838 Single Brushed DC Motor Driver Carrier.

Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view.

DRV8835 dual motor driver carrier.

Current sensors: We have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

We also incorporate these motors into some of our products, including our Zumo robot and 3pi robot :

Assembled Zumo 32U4 robot.

Pololu 3pi robot.

We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.

Some of the Pololu metal gearmotors.

People often buy this product together with:

This gearmotor is a miniature low-power, 6 V brushed DC motor with a 100.37:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.Key specs at 6 V: 120 RPM and 40 mA with no load, 12 oz-in (0.9 kg-cm) and 0.36 A at stall.

These tiny brushed DC gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with five different motors: high-power 6 V and 12 V motors with long-life carbon brushes (HPCB), and high-power (HP), medium power (MP), and low power (LP) 6 V motors with shorter-life precious metal brushes. The 6 V and 12 V HPCB motors offer the same performance at their respective nominal voltages, just with the 12 V motor drawing half the current of the 6 V motor. The 6 V HPCB and 6 V HP motors are identical except for their brushes, which only affect the lifetime of the motor.

The HPCB versions (shown on the left in the picture below) can be differentiated from versions with precious metal brushes (shown on the right) by their copper-colored terminals. Note that the HPCB terminals are 0.5 mm wider than those on the other micro metal gearmotor versions (2 mm vs. 1.5 mm), and they are about 1 mm closer together (6 mm vs. 7 mm).

Versions of these gearmotors are also available with an additional 1 mm-diameter output shaft that protrudes from the rear of the motor. This 4.5 mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our magnetic encoder for micro metal gearmotors (see the picture on the right), to provide motor speed or position feedback.

With the exception of the 1000:1 gear ratio versions, all of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change.

Please see the micro metal gearmotor datasheet (2MB pdf) for more information, including detailed performance graphs for each micro metal gearmotor version. You can also use our dynamically sortable micro metal gearmotor comparison table for search for the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below.

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. The recommended upper limit for instantaneous torque is 35 oz-in (2.5 kg-cm) for the 1000:1 gearboxes and 25 oz-in (2 kg*cm) for all the other gear ratios; we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP and HPCB) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Exact gear ratio: ``(35×37×35×38) / (12×11×13×10) ~~ bb(100.37:1)``

In terms of size, these gearmotors are very similar to Sanyo’s popular 12 mm NA4S DC gearmotors, and gearmotors with this form factor are occasionally referred to as N20 motors. The versions with carbon brushes (HPCB) have slightly different terminal and end-cap dimensions than the versions with precious metal brushes, but all of the other dimensions are identical.

Dimensions of versions with carbon brushes (HPCB)

Dimensions of the Pololu micro metal gearmotors with carbon brushes (HPCB). Units are mm over [inches].

Dimensions of versions with precious metal brushes (LP, MP, and HP)

Dimensions of the Pololu micro metal gearmotors with precious metal brushes: low-power (LP), medium-power (MP), and high-power (HP). Units are mm over [inches].

These diagrams are also available as a downloadable PDF (262k pdf).

Wheels and hubs: The micro metal gearmotor’s output shaft matches our assortment of Pololu wheels and the Solarbotics RW2i rubber wheel. You can also use our Pololu universal mounting hubs to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft, and you can use our 12mm hex wheel adapter to use this motor with many common hobby RC wheels.

Pololu wheel 32×7mm on a micro metal gearmotor.

Black Pololu 70×8mm wheel on a Pololu micro metal gearmotor.

A pair of Pololu universal aluminum mounting hubs for 3 mm diameter shafts.

12mm Hex Wheel Adapter for 3mm Shaft on a Micro Metal Gearmotor.

Mounting brackets: Our mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm. Our micro metal gearmotors will also work with our 15.5D mm metal gearmotor bracket pair.

Black micro metal gearmotor mounting bracket pair with included screws and nuts.

White micro metal gearmotor mounting bracket pair with included screws and nuts.

Pololu micro metal gearmotor bracket extended with micro metal gearmotor.

Quadrature encoders: We offer several quadrature encoders that work with our micro metal gearmotors.

Magnetic Encoder Kit for Micro Metal Gearmotors assembled with ribbon cable wires.

Example of an installed micro metal gearmotor reflective optical encoder.

Note: The HPCB versions of our micro metal gearmotors are not compatible with our #2590 and #2591 optical encoders or our older #2598 magnetic encoders (the terminals are too wide to fit through the corresponding holes in the encoder boards). However, they are compatible with our newer #3081 magnetic encoders.

Motor controllers and drivers: We have a number of motor controllers, motor drivers, and robot controllers that make it easy to drive these micro metal gearmotors. For the 6 V micro metal gearmotors, consider the DRV8838 single-channel motor driver carrier, the DRV8833 dual motor driver carrier, and DRV8835 dual motor driver carrier (or DRV8835 shield for Arduino). For the 12 V micro metal gearmotors, consider the MAX14870 single-channel motor driver carrier, DRV8801 single-channel motor driver carrier, and A4990 dual motor driver carrier (or A4990 shield for Arduino).

DRV8838 Single Brushed DC Motor Driver Carrier.

Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view.

DRV8835 dual motor driver carrier.

Current sensors: We have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

We also incorporate these motors into some of our products, including our Zumo robot and 3pi robot :

Assembled Zumo 32U4 robot.

Pololu 3pi robot.

We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.

Some of the Pololu metal gearmotors.

People often buy this product together with:

This gearmotor is a miniature high-power, 6 V brushed DC motor with a 100.37:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter. This version also has a 4.5 × 1 mm extended motor shaft.Key specs at 6 V: 320 RPM and 120 mA with no load, 30 oz-in (2.2 kg-cm) and 1.6 A at stall.

These tiny brushed DC gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with five different motors: high-power 6 V and 12 V motors with long-life carbon brushes (HPCB), and high-power (HP), medium power (MP), and low power (LP) 6 V motors with shorter-life precious metal brushes. The 6 V and 12 V HPCB motors offer the same performance at their respective nominal voltages, just with the 12 V motor drawing half the current of the 6 V motor. The 6 V HPCB and 6 V HP motors are identical except for their brushes, which only affect the lifetime of the motor.

The HPCB versions (shown on the left in the picture below) can be differentiated from versions with precious metal brushes (shown on the right) by their copper-colored terminals. Note that the HPCB terminals are 0.5 mm wider than those on the other micro metal gearmotor versions (2 mm vs. 1.5 mm), and they are about 1 mm closer together (6 mm vs. 7 mm).

Versions of these gearmotors are also available with an additional 1 mm-diameter output shaft that protrudes from the rear of the motor. This 4.5 mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our magnetic encoder for micro metal gearmotors (see the picture on the right), to provide motor speed or position feedback.

With the exception of the 1000:1 gear ratio versions, all of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change.

Please see the micro metal gearmotor datasheet (2MB pdf) for more information, including detailed performance graphs for each micro metal gearmotor version. You can also use our dynamically sortable micro metal gearmotor comparison table for search for the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below.

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. The recommended upper limit for instantaneous torque is 35 oz-in (2.5 kg-cm) for the 1000:1 gearboxes and 25 oz-in (2 kg*cm) for all the other gear ratios; we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP and HPCB) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Exact gear ratio: ``(35×37×35×38) / (12×11×13×10) ~~ bb(100.37:1)``

In terms of size, these gearmotors are very similar to Sanyo’s popular 12 mm NA4S DC gearmotors, and gearmotors with this form factor are occasionally referred to as N20 motors. The versions with carbon brushes (HPCB) have slightly different terminal and end-cap dimensions than the versions with precious metal brushes, but all of the other dimensions are identical.

Dimensions of versions with carbon brushes (HPCB)

Dimensions of the Pololu micro metal gearmotors with carbon brushes (HPCB). Units are mm over [inches].

Dimensions of versions with precious metal brushes (LP, MP, and HP)

Dimensions of the Pololu micro metal gearmotors with precious metal brushes: low-power (LP), medium-power (MP), and high-power (HP). Units are mm over [inches].

These diagrams are also available as a downloadable PDF (262k pdf).

Wheels and hubs: The micro metal gearmotor’s output shaft matches our assortment of Pololu wheels and the Solarbotics RW2i rubber wheel. You can also use our Pololu universal mounting hubs to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft, and you can use our 12mm hex wheel adapter to use this motor with many common hobby RC wheels.

Pololu wheel 32×7mm on a micro metal gearmotor.

Black Pololu 70×8mm wheel on a Pololu micro metal gearmotor.

A pair of Pololu universal aluminum mounting hubs for 3 mm diameter shafts.

12mm Hex Wheel Adapter for 3mm Shaft on a Micro Metal Gearmotor.

Mounting brackets: Our mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm. Our micro metal gearmotors will also work with our 15.5D mm metal gearmotor bracket pair.

Black micro metal gearmotor mounting bracket pair with included screws and nuts.

White micro metal gearmotor mounting bracket pair with included screws and nuts.

Pololu micro metal gearmotor bracket extended with micro metal gearmotor.

Quadrature encoders: We offer several quadrature encoders that work with our micro metal gearmotors.

Magnetic Encoder Kit for Micro Metal Gearmotors assembled with ribbon cable wires.

Example of an installed micro metal gearmotor reflective optical encoder.

Note: The HPCB versions of our micro metal gearmotors are not compatible with our #2590 and #2591 optical encoders or our older #2598 magnetic encoders (the terminals are too wide to fit through the corresponding holes in the encoder boards). However, they are compatible with our newer #3081 magnetic encoders.

Motor controllers and drivers: We have a number of motor controllers, motor drivers, and robot controllers that make it easy to drive these micro metal gearmotors. For the 6 V micro metal gearmotors, consider the DRV8838 single-channel motor driver carrier, the DRV8833 dual motor driver carrier, and DRV8835 dual motor driver carrier (or DRV8835 shield for Arduino). For the 12 V micro metal gearmotors, consider the MAX14870 single-channel motor driver carrier, DRV8801 single-channel motor driver carrier, and A4990 dual motor driver carrier (or A4990 shield for Arduino).

DRV8838 Single Brushed DC Motor Driver Carrier.

Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view.

DRV8835 dual motor driver carrier.

Current sensors: We have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

We also incorporate these motors into some of our products, including our Zumo robot and 3pi robot :

Assembled Zumo 32U4 robot.

Pololu 3pi robot.

We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.

Some of the Pololu metal gearmotors.

People often buy this product together with:

The Parallax continuous rotation servo is a Futaba S148 servo that has been modified for continuous rotation. Since servos have their own integrated control circuitry, this unit gives you an easy way to get your robot moving.Key specs at 6 V: 50 RPM (no-load), 38 oz-in (2.7 kg-cm), 43 g

Parallax (Futaba S148) continuous rotation servo.

The Parallax (Futaba S148) continuous rotation servo converts standard RC servo position pulses into continuous rotation speed. It can be controlled directly by a microcontroller without any additional electronics, which makes it a great actuator for robotics projects. The servo includes an adjustable potentiometer that can be used to center the servo and comes with a star-shaped servo horn and an 11″ (270 mm) lead.

Specs

Power: 4.8 – 6 V

Top 6 V speed: 50 RPM (with no load)

Torque: 2.7 kg-cm/38 oz-in at 6 V

Weight: 43 g/1.5 oz with servo horn and screw

Size (L x W x H): 40.5 mm x 20.0 mm x 36.1 mm / 1.60" x 0.8" x 1.42"

Control interface: RC servo pulse width control, 1.50 ms neutral

Manual adjustment port

This servo is compatible with our servo controllers and our servo wheels and sprockets.

Continuous rotation servo size comparison. From left to right: SpringRC SM-S4303R, Power HD AR-3606HB, FEETECH FS5106R, Parallax Feedback 360°, Parallax (Futaba S148), and FEETECH FS90R.

People often buy this product together with:

The HD-1440A analog servo from Power HD is one of the smallest servos we carry and is a great, inexpensive, tiny actuator for a small robot mechanism. Servo horns and associated hardware are included.Key specs at 6 V: 0.10 sec/60°, 11 oz-in (0.8 kg-cm), 4.4 g.

An example of hardware included with the Power HD sub-micro servo HD-1440A and the sub-micro servo 3.7g (generic). Actual hardware might vary.

This is a great general-purpose actuator for tiny mechanisms. The lead is terminated with a standard “JR”-style connector, which is Futaba-compatible. Mounting screws and an assortment of servo horns is included with this servo (hardware might vary). You can find more information about this servo under the specifications tab and in its datasheet (379k pdf).

Note that, as with most hobby servos, stalling or back-driving this servo can strip its gears.

Note: The case of this servo has changed from translucent blue to solid black (pictures of the two versions are available under the pictures tab).

People often buy this product together with:

Battery holder for eight AAA cells arranged as two back-to-back four-cell holders.

This battery holder features two 6", 24-gauge leads that have 5 mm of insulation stripped off of the ends.

People often buy this product together with:

This programmable module combines with a Raspberry Pi to serve as the control center of a small robot or electronics project. Its ATmega32U4 AVR microcontroller comes preloaded with an Arduino-compatible bootloader, and the board includes dual motor drivers that can deliver 1.8 A per channel to two brushed DC motors. An efficient voltage regulator (2.7 V to 11 V input) and level shifters enable it to power and communicate with a Raspberry Pi. This version (item #3117) is assembled with selected through-hole connectors and components installed for use as a Raspberry Pi add-on.

A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge, bottom view with dimensions.

The A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge is a programmable module well-suited for robotics applications, designed to work either as an auxiliary controller mounted to a Raspberry Pi or as a standalone control solution for a small robot. This A-Star (abbreviated A*) is based on the ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), which has built-in USB functionality, and it ships with a preloaded Arduino-compatible bootloader. Its complement of peripheral hardware includes dual motor drivers capable of delivering a continuous 1.8 A per channel, along with pushbuttons, LEDs, and an optional buzzer for building a user interface. An efficient switching voltage regulator allows the controller to work over a wide range of input voltages (2.7 V to 11 V).

The robot controller board conforms to the Raspberry Pi HAT specification, allowing it to be used as an add-on for a Raspberry Pi with a 40-pin GPIO header (Model B+ or newer, including Pi 3 Model B and Model A+) . On-board level shifters make it easy to set up I²C communication and interface other signals between the two controllers, and the A-Star automatically supplies 5 V power to an attached Raspberry Pi. In this setup, the Raspberry Pi can handle the high-level robot control while relying on the A-Star for low-level tasks like reading analog sensors and controlling timing-sensitive devices (e.g. servos).

We provide a library that helps establish communication between the A-Star and a Raspberry Pi, as well as a tutorial that demonstrates how to use the library and its included example code to build such a robot.

Our comprehensive user’s guide provides the basics you need to get started with the A-Star as well as detailed technical information for advanced users.

This product requires a USB A to Micro-B cable (not included) to connect to a computer.

Driving motors with an A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge on a Raspberry Pi Model B+ or Pi 2 Model B.

A-Star 32U4 Robot Controller LV (2.7 V to 11 V) configurations:

Item #3116: Surface mount components only (no through-hole components or mounting hardware)

Item #3117: Assembled with selected through-hole components for use as a Raspberry Pi add-on (Raspberry Pi mounting hardware included)

A-Star 32U4 Robot Controller SV (5.5 V to 36 V) configurations:

Item #3118: Surface mount components only (no through-hole components or mounting hardware)

Item #3119: Assembled with selected through-hole components for use as a Raspberry Pi add-on (Raspberry Pi mounting hardware included)

Dimensions: 65 mm × 56 mm (2.6″ × 2.2″)

Programmable ATmega32U4 MCU with 32 KB flash, 2.5 KB SRAM, 1 KB EEPROM, and native full-speed USB (clocked by precision 16 MHz crystal oscillator)

Preloaded with Arduino-compatible bootloader (no external programmer required)

All 26 general-purpose I/O lines from the ATmega32U4 are broken out (including PB0, PD5, and PE2); 7 of these can be used as hardware PWM outputs and 12 of these can be used as analog inputs (some I/O lines are used by on-board hardware)

Convenient 0.1″-spaced power, ground, and signal connection points

Dual bidirectional DRV8838 motor drivers (1.8 A per channel)

Buzzer option for simple sounds and music

3 user-controllable LEDs

3 user pushbuttons

Reset button

Level shifters for interfacing 5 V logic to 3.3 V Raspberry Pi

Power features:

5 V power can be sourced from USB or from a 2.7 V to 11 V external supply through on-board regulator (with several access points for connecting external power)

Switching 5 V regulator enables efficient operation

Power switch for external power inputs

Reverse-voltage protection on external power inputs

Power selection circuit allows for seamless switching between power sources while providing overcurrent protection, and feedback about which power source is selected

Provides 5 V power to Raspberry Pi

5 V power can be sourced from USB or from a 2.7 V to 11 V external supply through on-board regulator (with several access points for connecting external power)

Switching 5 V regulator enables efficient operation

Power switch for external power inputs

Reverse-voltage protection on external power inputs

Power selection circuit allows for seamless switching between power sources while providing overcurrent protection, and feedback about which power source is selected

Provides 5 V power to Raspberry Pi

6-pin ISP header for use with an external programmer

Comprehensive user’s guide

A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge with included hardware.

This version of the A-Star 32U4 Robot Controller LV with Raspberry Pi Bridge (2.7 V to 11 V input voltage) is assembled with selected through-hole connectors and components for use as a Raspberry Pi expansion board, as shown in the picture above. A 2×20-pin 0.1″ female header is preinstalled to serve as a Raspberry Pi GPIO connector, and a 6-pin strip of terminal blocks and a DC power jack are mounted for motor and power connections. A buzzer is also installed, along with two 2×1-pin male headers and shorting blocks for the buzzer and battery level jumpers.

This version ships with a set of four M2.5 standoffs (11 mm length), screws, and nuts that can be used to secure the board to the Raspberry Pi at the proper height for the GPIO connector.

For a version with SMT components only, making it more suitable for standalone use and allowing customization of through-hole components, see item #3116. For example, if you want to continue to have access to the Raspberry Pi’s 40 GPIO pins while the A-Star is plugged in, you can get the SMT-only version and install a stackable 2×20-pin female header.

A major feature of the A* Robot Controller LV is its power system, which allows it to efficiently operate from a 2.7 V to 11 V external source and provide power to an attached Raspberry Pi. The input voltage is regulated to 5 V by a TPS63061 switching step-up/step-down (buck-boost) converter from Texas Instruments. (We also make a standalone regulator based on this integrated circuit.) The regulator’s flexibility in input voltage is especially well-suited for battery-powered applications in which the battery voltage begins above 5 V and drops below 5 V as the battery discharges. Without the typical restriction on the battery voltage staying above 5 V throughout its life, a wider range of battery types can be considered. For example:

A 4-cell battery holder, which might have a 6 V output with fresh alkalines or a 4.0 V output with partially discharged NiMH cells, can be used to power this A*.

A disposable 9 V battery powering the board can be discharged to under 3 V instead of cutting out at 6 V, as with typical linear or step-down regulators.

As shown in the left graph below, the LV’s 5 V switching regulator has an efficiency – defined as (Power out)/(Power in) – of 80% to 90% for most combinations of input voltage and load.

The A-Star’s components, including the microcontroller and LEDs, draw 30 mA to 40 mA in typical applications (without the buzzer). The rest of the regulator’s achievable output current, which depends on input voltage as well as ambient conditions, can be used to power other devices; this can include an attached Raspberry Pi (which typically draws a few hundred milliamps). The blue line in the right graph above shows output currents at which the voltage regulator’s over-temperature protection typically kicks in after a few seconds. These currents represent the limit of the regulator’s capability and cannot be sustained for long periods; under typical operating conditions, a safe limit for the maximum continuous regulator output current is 60% to 70% of the values shown in the graph.

Like our other A-Star 32U4 programmable controllers, the A-Star 32U4 Robot Controller ships with a preloaded Arduino-compatible bootloader (which uses 4 KB of flash memory, leaving 28 KB available for the user program). We provide a software add-on that enables the board to be easily programmed from the Arduino environment and an Arduino library to make it easy to use the additional on-board hardware.

The A-Star 32U4 Robot Controller has the same microcontroller as the Arduino Leonardo and Arduino Micro, and it runs at the same frequency, so most code examples intended for those boards should also work on the A-Star.

The A-Star 32U4 Robot Controller is a part of our larger A-Star 32U4 family, all of whose members are based on the same ATmega32U4 microcontroller, feature native USB interfaces, and are preloaded with Arduino-compatible bootloaders. The table below shows some key features and specifications of our A-Star microcontroller boards to help you choose the right one for your application.

People often buy this product together with:

This programmable module combines with a Raspberry Pi to serve as the control center of a small robot or electronics project. Its ATmega32U4 AVR microcontroller comes preloaded with an Arduino-compatible bootloader, and the board includes dual motor drivers that can deliver 1.7 A per channel to two brushed DC motors. An efficient voltage regulator (5.5 V to 36 V input) and level shifters enable it to power and communicate with a Raspberry Pi. This version (item #3119) is assembled with selected through-hole connectors and components installed for use as a Raspberry Pi add-on.

A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge, bottom view with dimensions.

The A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge is a programmable module well-suited for robotics applications, designed to work either as an auxiliary controller mounted to a Raspberry Pi or as a standalone control solution for a small robot. This A-Star (abbreviated A*) is based on the ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), which has built-in USB functionality, and it ships with a preloaded Arduino-compatible bootloader. Its complement of peripheral hardware includes dual motor drivers capable of delivering a continuous 1.7 A per channel, along with pushbuttons, LEDs, and an optional buzzer for building a user interface. An efficient switching voltage regulator allows the controller to work over a wide range of input voltages (5.5 V to 36 V).

The robot controller board conforms to the Raspberry Pi HAT specification, allowing it to be used as an add-on for a Raspberry Pi with a 40-pin GPIO header (Model B+ or newer, including Pi 3 Model B and Model A+). On-board level shifters make it easy to set up I²C communication and interface other signals between the two controllers, and the A-Star automatically supplies 5 V power to an attached Raspberry Pi. In this setup, the Raspberry Pi can handle the high-level robot control while relying on the A-Star for low-level tasks like reading analog sensors and controlling timing-sensitive devices (e.g. servos).

We provide a library that helps establish communication between the A-Star and a Raspberry Pi, as well as a tutorial that demonstrates how to use the library and its included example code to build such a robot.

Our comprehensive user’s guide provides the basics you need to get started with the A-Star as well as detailed technical information for advanced users.

This product requires a USB A to Micro-B cable (not included) to connect to a computer.

Driving motors with an A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge on a Raspberry Pi Model B+ or Pi 2 Model B.

A-Star 32U4 Robot Controller SV (5.5 V to 36 V) configurations:

Item #3118: Surface mount components only (no through-hole components or mounting hardware)

Item #3119: Assembled with selected through-hole components for use as a Raspberry Pi add-on (Raspberry Pi mounting hardware included)

A-Star 32U4 Robot Controller LV (2.7 V to 11 V) configurations:

Item #3116: Surface mount components only (no through-hole components or mounting hardware)

Item #3117: Assembled with selected through-hole components for use as a Raspberry Pi add-on (Raspberry Pi mounting hardware included)

Dimensions: 65 mm × 56 mm (2.6″ × 2.2″)

Programmable ATmega32U4 MCU with 32 KB flash, 2.5 KB SRAM, 1 KB EEPROM, and native full-speed USB (clocked by precision 16 MHz crystal oscillator)

Preloaded with Arduino-compatible bootloader (no external programmer required)

All 26 general-purpose I/O lines from the ATmega32U4 are broken out (including PB0, PD5, and PE2); 7 of these can be used as hardware PWM outputs and 12 of these can be used as analog inputs (some I/O lines are used by on-board hardware)

Convenient 0.1″-spaced power, ground, and signal connection points

Dual bidirectional MAX14870 motor drivers (1.7 A continuous per channel, 2.5 A peak per channel)

Buzzer option for simple sounds and music

3 user-controllable LEDs

3 user pushbuttons

Reset button

Level shifters for interfacing 5 V logic to 3.3 V Raspberry Pi

Power features:

5 V power can be sourced from USB or from 5.5 V to 36 V external supply through on-board regulator (with several access points for connecting external power)

Switching 5 V regulator enables efficient operation

Power switch for external power inputs

Reverse-voltage protection on external power inputs

Power selection circuit allows for seamless switching between power sources while providing overcurrent protection, and feedback about which power source is selected

Provides 5 V power to Raspberry Pi

5 V power can be sourced from USB or from 5.5 V to 36 V external supply through on-board regulator (with several access points for connecting external power)

Switching 5 V regulator enables efficient operation

Power switch for external power inputs

Reverse-voltage protection on external power inputs

Power selection circuit allows for seamless switching between power sources while providing overcurrent protection, and feedback about which power source is selected

Provides 5 V power to Raspberry Pi

6-pin ISP header for use with an external programmer

Comprehensive user’s guide

A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge with included hardware.

This version of the A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge (5.5 V to 36 V input voltage) is assembled with selected through-hole connectors and components for use as a Raspberry Pi expansion board, as shown in the picture above. A 2×20-pin 0.1″ female header is preinstalled to serve as a Raspberry Pi GPIO connector, and a 6-pin strip of terminal blocks and a DC power jack are mounted for motor and power connections. A buzzer is also installed, along with two 2×1-pin male headers and shorting blocks for the buzzer and battery level jumpers.

This version ships with a set of four M2.5 standoffs (11 mm length), screws, and nuts that can be used to secure the board to the Raspberry Pi at the proper height for the GPIO connector.

For a version with SMT components only, making it more suitable for standalone use and allowing customization of through-hole components, see item #3118. For example, if you want to continue to have access to the Raspberry Pi’s 40 GPIO pins while the A-Star is plugged in, you can get the SMT-only version and install a stackable 2×20-pin female header.

A major feature of the A* Robot Controller SV is its power system, which allows it to efficiently operate from a 5.5 V to 36 V external source and provide power to an attached Raspberry Pi. The input voltage is regulated to 5 V by an MP4423H switching step-down (buck) converter from Monolithic Power Systems. (We also make a standalone regulator based on this integrated circuit.)

As shown in the left graph below, the SV’s 5 V switching regulator has an efficiency – defined as (Power out)/(Power in) – of 80% to 95% for most combinations of input voltage and load.

The A-Star’s components, including the microcontroller and LEDs, draw 30 mA to 40 mA in typical applications (without the buzzer). The rest of the regulator’s achievable output current, which depends on input voltage as well as ambient conditions, can be used to power other devices; this can include an attached Raspberry Pi (which typically draws a few hundred milliamps). The green line in the right graph above shows the output currents where the regulator’s output voltage drops below 4.75 V. These currents are close to the limits of the regulator’s capability and generally cannot be sustained for long periods; under typical operating conditions, a safe limit for the maximum continuous regulator output current is 60% to 70% of the values shown in the graph.

The dropout voltage of a step-down regulator is defined as the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to assure the target output can be achieved. As can be seen in the graph below, the dropout voltage of the Robot Controller SV’s regulator increases approximately linearly with the output current. For light loads where the dropout voltage is small, the board can operate almost down to 5 V. However, for larger loads, the dropout voltage should be taken into consideration when selecting a power supply; operating above 6 V will ensure the full output current is available.

Note: Batteries can have much higher voltages than their nominal voltages when fully charged, so be careful with nominal voltages above 24 V. A 36 V battery is not appropriate for this product.

Like our other A-Star 32U4 programmable controllers, the A-Star 32U4 Robot Controller ships with a preloaded Arduino-compatible bootloader (which uses 4 KB of flash memory, leaving 28 KB available for the user program). We provide a software add-on that enables the board to be easily programmed from the Arduino environment and an Arduino library to make it easy to use the additional on-board hardware.

The A-Star 32U4 Robot Controller has the same microcontroller as the Arduino Leonardo and Arduino Micro, and it runs at the same frequency, so most code examples intended for those boards should also work on the A-Star.

The A-Star 32U4 Robot Controller is a part of our larger A-Star 32U4 family, all of whose members are based on the same ATmega32U4 microcontroller, feature native USB interfaces, and are preloaded with Arduino-compatible bootloaders. The table below shows some key features and specifications of our A-Star microcontroller boards to help you choose the right one for your application.

People often buy this product together with:

This single-pole, double-throw (SPDT) momentary switch can be used as a general-purpose micro switch, but the long lever arm makes it especially useful as a tactile bump sensor for your robot (e.g whiskers or antennae). The switch body dimension is 20.0 x 6.4 x 10.2 mm, and the lever arm is 50 mm long.

This single-pole, double-throw (SPDT) momentary switch can be used as a general-purpose micro switch, but the 2"-long lever arm makes it especially useful as a simple tactile obstacle-detector for your robot. The switch body dimension is 20.0 x 6.4 x 10.2 mm (0.79" x 0.25" x 0.40"), and the lever arm is 50 mm (2") long. This three-pin switch can also be used as a two-pin single-pole, single-throw (SPST) switch that is open or closed by default, depending on which two pins are used.

Dimensions (in mm) of snap-action switch with 50mm lever: 3-pin, SPDT, 5A.

For a more sophisticated tactile sensor, see our force-sensing resistors.

People often buy this product together with:

This single-pole, double-throw (SPDT) momentary switch can be used as a general-purpose micro switch or tactile bump sensor for your robot. The switch body dimension is 20.0 x 6.4 x 10.2 mm, and the 16.3mm lever arm is has a roller at the tip.

This single-pole, double-throw (SPDT) momentary switch can be used as a general-purpose micro switch or tactile obstacle-detector for your robot. The switch body dimension is 20.0 x 6.4 x 10.2 mm (0.79" x 0.25" x 0.40"), and the 16.3mm (0.64") lever arm has a roller at the tip. This three-pin switch can also be used as a two-pin single-pole, single-throw (SPST) switch that is open or closed by default, depending on which two pins are used.

Dimensions (in mm) of snap-action switch with 16.3mm roller lever: 3-pin, SPDT, 5A.

For a more sophisticated tactile sensor, see our force-sensing resistors.

People often buy this product together with:

The Parallax ColorPAL combines an RGB LED, a light sensor, and a microcontroller to make a color sensor that can also be used as an ambient light detector and a color generator. Readings are reported via a 1-wire asynchronous serial interface.

ColorPAL side view.

The ColorPAL from Parallax is a miniature color and light sensor that can double as a color generator with its RGB LED. When sensing color, the ColorPAL uses its LED to illuminate a sample one color component at a time while measuring the light reflected back with a broad-spectrum light-to-voltage converter. The amount of light reflected from the sample under illumination from each red, green, and blue LED can be used to determine the sample’s color. For the ColorPAL to detect the color of a subject, the subject must be reflective and non-fluorescent. The color of objects that emit light (e.g. LEDs) cannot be detected.

Detects a wide range of colors and outputs data as 10-bit RGB (Red/Green/Blue) components.

Detects broad-spectrum ambient light with sensitivity down to 44µW/cm2 per lsb.

Generates 24-bit color using onboard RGB LED.

Plugs into servo headers or cables or solderless breadboards.

Single-pin interface uses a simple serial protocol to define and initiate color detection and generation.

Color detection and generation details handled by onboard microcontroller.

Onboard EEPROM for saving custom color detection and generation programs.

Autorun feature permits running a pre-designated EEPROM program with only a power supply.

Power requirements: 5.0 VDC

Communication: 1-wire serial (asynchronous, non-inverted, open-drain serial protocol) with automatic baud rate detection from 2400 – 7200 bps

Dimensions: 1.72 × 0.90 × 0.65 in (44 × 23 × 17 mm)

Communication with the ColorPAL takes place using serial I/O, transmitting and receiving at between 2400 and 7200 baud, using a non-inverted, open-drain protocol. The ColorPAL includes a pull-up resistor to Vdd, so you do not need to apply one externally. Because of the open-drain protocol, the pin used to communicate with the ColorPAL should always be configured as an input, except when being driven low. Also, when starting up, you should wait for this pin to be pulled high by the ColorPAL before trying to send it any commands. Please see the user’s manual (297k pdf) for more information.

People often buy this product together with:

Use this motor driver and power distribution board to get your Romi chassis running quickly. It offers all of the same features as the smaller Power Distribution board for Romi Chassis — battery contact slots, reverse voltage protection, several power switching options, and easy access to the various power busses — and adds a two-channel motor driver and powerful switching step-down regulator that can supply a continuous 2.5 A at 5 V or 3.3 V. Just add a microcontroller and sensors to complete your Romi robot.

This motor driver and power distribution board is designed specifically for the Romi chassis as a convenient way to drive the chassis’s motors and power the rest of the electronics that make up your robot. It features two DRV8838 motor drivers, one for each of the chassis’s motors, and a powerful switching step-down regulator that can supply a continuous 2.5 A at 5 V or 3.3 V. The board has slots for soldering in the Romi chassis battery contact tabs, and it incorporates the power switching and distribution functionality from the Power Distribution Board for Romi Chassis, so it offers all of the same features: reverse voltage protection, several power switching options based on the patented latching circuit from the Pololu pushbutton power switch, and easy access to the various power buses.

The board has a small pushbutton already installed for controlling power (one push turns power on and another push turns it off) and offers convenient points for connecting external pushbutton or tactile switches in parallel. It also offers several alternate pushbutton connection options that result in push-on-only or push-off-only operation, and additional inputs enable further power control options like allowing your robot to turn off its own power. Alternatively, the board can be reconfigured to disable the pushbutton circuit and give control to the small installed slide switch.

The board’s control pins and power buses are accessible through a set of 0.1″-spaced pins that are compatible with standard 0.1″ male and 0.1″ female headers, and the power buses are also accessible through a larger set of holes that are compatible with 3.5mm-pitch terminal blocks (you can combine a 2-pin block and a 3-pin block into a single 5-pin block that spans the three power holes and two ground holes).

Two 1/4″ #2-56 screws and two #2-56 nuts are included for mounting the board to the Romi chassis, and two low-profile female headers are included for connecting the motors to the board.

Installation

Motor Driver and Power Distribution Board for Romi Chassis with included hardware.

Motor Driver and Power Distribution Board for Romi Chassis mounted on a chassis prior to motor installation.

Before installing the motor driver and power distribution board on a Romi chassis, you should solder any headers, terminal blocks, wires, or other connectors you plan to use on the board. You have a few options for connecting the Romi chassis’s motors to the board:

If you plan on using the Romi Encoder Pair Kit with your motors, we recommend you solder these included female headers into the outer sets of holes (closest to the edges of the board) directly below where the motors will be. With the Romi encoders mounted on your motors and their included male header pins installed facing down, they will plug directly into these female headers when you push the motors into the motor clips.

The Romi Encoder can plug directly into the Motor Driver and Power Distribution Board for Romi Chassis.

Alternatively, if you do not intend to use Romi encoders, we recommend soldering wires to your motor leads and installing 3.5mm-pitch terminal blocks to the motor driver output holes along the front edge of the board. These terminal blocks will let you make temporary connections between your motors and the motor driver board. We suggest connecting the forward lead of each motor to the + (positive) motor output so that the motor directions will match the behavior described below.

Please read the rest of this page carefully to determine what additional connectors you might want and where they should be installed.

It is possible to remove the board from the chassis later to solder additional connections, and some of the through holes can be soldered through the slots in the chassis while the board is mounted, but soldering beforehand is easier and avoids the risk of inadvertently melting the chassis with your soldering iron.

The four battery terminals should be soldered to the board after it is mounted on the chassis, as described in the chassis assembly instructions. You will be able to remove the board and battery contacts from the chassis as a single piece after soldering.

Once your you have soldered your through-hole connections to the motor driver and power distribution board, please follow the instructions given in the Pololu Romi Chassis User’s Guide to finish assembling the chassis, mounting the control board, and soldering in the battery contacts. (The diagrams in those instructions show assembly with the larger Romi 32U4 Control Board, but the same steps apply for the smaller motor driver and power distribution board.)

Motor drivers

The motor driver and power distribution board has two Texas Instruments DRV8838 motor drivers that can power the Romi chassis’s motors. We recommend careful reading of the DRV8838 datasheet (1MB pdf) for information about the drivers.

By default, the drivers’ motor voltage (VM) is supplied by the board’s switched battery voltage, VSW, and their logic voltage (VCCMD) is supplied by the on-board regulator output, VREG (5 V by default). If you want to customize these voltages, you can cut the jumpers labeled VM = VSW and VCCMD = VREG and connect appropriate supplies to the VM and VCCMD pins.

The DRV8838 offers a simple two-pin PHASE/ENABLE control interface, which this board makes available for each motor as DIR and PWM, respectively. The DIR pin determines the motor direction (low drives the motor forward, high drives it in reverse) and the PWM pin can be supplied with a PWM signal to control the motor speed. The DIR and PWM control inputs are pulled low through weak internal pull-down resistors (approximately 100 kΩ). When the PWM pin is low, the motor outputs are both shorted to ground, which results in dynamic braking of a connected motor.

The two drivers’ SLEEP pins (labeled SLP) are connected together by default and can be driven low to put the drivers into a low-power sleep mode and turn off the motor outputs, which is useful if you want to let the motors coast. The SLEEP pins are pulled high through 10 kΩ pull-up resistors on the board so that the drivers are awake by default. In most applications, these pins can be left disconnected; if you want independent control of SLEEP on each side, you can cut the jumper labeled SLP L = R. The two SLEEP pins should not be driven separately without cutting this jumper.

The following simplified truth table shows how each driver operates:

Encoder connections

The motor driver and power distribution board is designed to allow the Romi Encoder Pair Kit to plug directly into the encoder headers. The encoders can be used to track the rotational speed and direction of the robot’s drive wheels. They provide a resolution of 12 counts per revolution of the motor shaft when counting both edges of both channels, which corresponds to approximately 1440 counts per revolution of the Romi’s wheels. For more information about the specifications of the Romi encoders, please see the Romi Encoder Pair Kit product page.

For typical use, one set of through holes on each side of the motor power and distribution board will be populated with the female header for the encoder board; we recommend using the outer set on each side for this purpose. The remaining set of through holes can be used to make connections to the encoder signals.

For both encoders, channel B leads channel A when the motor is rotating in the forward direction; that is, B rises before A rises and B falls before A falls. Note that this description designates the A and B signals as labeled on the motor driver and power distribution board itself, which puts A in front on both sides.

By default, both the logic voltage for the encoders (VCCENC) and the pull-up voltage for the open-drain encoder outputs (VPU) are supplied by the on-board regulator output, VREG (5 V by default). If you want to customize these voltages, you can cut the jumpers labeled VCCENC = VREG and VPU = VREG and connect appropriate supplies to the VCCENC and VPU pins.

Power switch circuit

By default, the on-board pushbutton can be used to toggle power: one push turns on power and another turns it off. Alternatively, a separate pushbutton can be connected to the BTNA and BTNB pins and used instead. Multiple pushbuttons can be wired in parallel for multiple control points, and each of the parallel pushbuttons, including the one on the board itself, will be able to turn the switch on or off. The latching circuit performs some button debouncing, but pushbuttons with excessive bouncing (several ms) might not function well with it.

For proper pushbutton operation, the board’s slide switch should be left in its Off position. (Sliding the switch to the On position will cause the board power to latch on, and the switch must be returned to the Off position before the board can be turned off with the pushbutton.)

Alternatively, to disable the pushbutton, you can cut the button jumper labeled Btn Jmp; this transfers control of the board’s power to the on-board slide switch instead. A separate slide or toggle switch can be connected to the GATE pin and used instead.

More advanced control options are available through the button connection pins and four control inputs:

Power distribution

The diagram below shows the layout of the power distribution buses and access points on the board.

VBAT is connected to the battery contact labeled BAT1+ and provides a direct connection to the battery supply. By default, VBAT is the high side of all six of the chassis’s AA battery cells in series, although this can be reconfigured with the battery jumper (see below).

VRP provides access to the battery voltage after reverse-voltage protection.

VSW is the battery voltage after reverse protection and the power switch circuit. By default, it provides power to the motors (VM) through the on-board motor drivers.

VREG is the output of the on-board step-down voltage regulator (see the “Voltage regulator” section below). By default, it is 5 V and provides logic power to the motor drivers (VCCMD) and encoder connectors (VCCENC and VPU).

BAT2+ provides access to the high side of two AA cells in series. This can be useful if you reconfigure the board to provide two separate battery supplies as described below.

Voltage regulator

An MP4423H switching buck converter regulates the switched battery voltage (VSW) to provide a regulated output, VREG. The regulated output is 5 V by default, but it can be changed to 3.3 V by cutting the jumper labeled VREG Select. Under typical conditions, up to 2 A of current is available from the VREG output. (We also make a standalone regulator based on this integrated circuit.)

Battery supply configuration

The motor driver and power distribution board’s default configuration provides battery power, VBAT, from all six of the chassis’s AA cells in series (nominally about 7.2 V with rechargeable batteries or 9 V with alkaline batteries). However, the board’s battery jumper, labeled Bat Jmp, allows you to reconfigure the battery connections to provide two independent supplies: BAT1, with 4 cells in series (nominally 4.8 V rechargeable or 6 V alkaline), and BAT2, with 2 cells in series (nominally 2.4 V rechargeable or 3 V alkaline). Cutting the connection between the BAT1− and BAT2+ pads separates the two sets of batteries, and using solder to bridge the BAT1− and GND pads establishes a common ground between the two new supplies.

Warning: Do not bridge the BAT1− and GND pads without first disconnecting BAT1− from BAT2+. Failing to do so could create a short circuit across the BAT2 batteries.

Note that the onboard regulator might not be able to supply 5 V as reliably if VBAT is reconfigured to come from a 4-cell supply, especially if you are using rechargeable batteries.

Schematic

A simplified schematic diagram of this board is available for download: Schematic diagram of the Motor Driver and Power Distribution Board for Romi Chassis (272k pdf)

In addition to the motor driver and power distribution board, we have a few other boards designed to mount onto a Romi chassis:

The Romi 32U4 Control Board turns the Romi chassis into an integrated robot platform. In addition to the same motor drivers and power circuit (including 5 V regulator) found on this board, the Romi 32U4 board includes an on-board ATmega32U4 microcontroller, a number of other peripherals and sensors, and interfaces for an optional LCD or Raspberry Pi.

The Power Distribution Board for Romi Chassis is a more basic board that only includes reverse voltage protection and a pushbutton power switch circuit; it is intended to be a convenient way to access the chassis’s battery power and pass it on to the rest of your electronics.

People often buy this product together with:

The Romi 32U4 Control Board turns the Romi chassis into a programmable robot based on the Arduino-compatible ATmega32U4 MCU. Its features include integrated dual motor drivers, a versatile power circuit, and inertial sensors, as well as connections for quadrature encoders and an optional LCD. The board also has the ability to interface with an added Raspberry Pi, making the foundation for a complete Raspberry Pi-controlled Romi robot.

The Romi 32U4 Control Board is designed to be assembled with a Romi chassis to create a capable integrated robot platform that can easily be programmed and customized.

Like our A-Star 32U4 programmable controllers, the Romi 32U4 Control Board is built around a USB-enabled ATmega32U4 AVR microcontroller from Microchip (formerly Atmel), and it ships preloaded with an Arduino-compatible bootloader. The control board features two H-bridge motor drivers and is designed to connect to a Romi Encoder Pair Kit (available separately) to allow closed-loop motor control. It also includes a powerful 5 V switching step-down regulator that can supply up to 2 A continuously, along with a versatile power switching and distribution circuit. A 3-axis accelerometer and gyro enable a Romi 32U4 robot to make inertial measurements, estimate its orientation, and detect external forces. Three on-board pushbuttons offer a convenient interface for user input, while indicator LEDs, a buzzer, and a connector for an optional LCD allow the robot to provide feedback.

Romi 32U4 Control Board on a Romi chassis, top view.

Romi 32U4 Control Board with LCD on a Romi chassis.

The Romi 32U4 Control Board can be used either as a standalone control solution or as a base for a more powerful Raspberry Pi controller. Its on-board connector and mounting holes allow a compatible Raspberry Pi (Model B+ or newer, including Pi 3 Model B and Model A+) to plug directly into the control board. Integrated level shifters make it easy to set up I²C communication and interface other signals between the two controllers, and the control board automatically supplies 5 V power to an attached Raspberry Pi. In this setup, the Raspberry Pi can handle the high-level robot control while relying on the Romi 32U4 Control Board for low-level tasks, like running motors, reading encoders, and interfacing with other analog or timing-sensitive devices.

Romi 32U4 Control Board with Raspberry Pi on a Romi chassis.

The I/O lines of both the ATmega32U4 and the Raspberry Pi are broken out to 0.1″-spaced through-holes along the front and rear of the control board, and the board’s power rails are similarly accessible, enabling sensors and other peripherals to easily be connected.

A software add-on is available that makes it easy to program a Romi 32U4 robot from the Arduino environment, and we have Arduino libraries and example sketches to help get you started. A USB A to Micro-B cable (not included) is required for programming.

The Romi 32U4 Control Board ships with all of its surface-mount components populated, and it includes a number of through-hole parts and mounting hardware, as shown in the picture above. Note that assembly (including soldering) is required; please see the user’s guide for assembly instructions.

The Romi chassis itself and other parts required to build a complete Romi 32U4 robot are not included; these are listed below, along with some optional additions.

What you will need

To build a robot with the Romi 32U4 Control Board, you will need a few additional parts:

a Romi Chassis Kit (this includes motors, wheels, one ball caster, and battery contacts)

a Romi Encoder Pair Kit

six AA batteries; The Romi chassis and control board work with both alkaline and NiMH batteries, though we recommend rechargeable NiMH cells

a USB A to Micro-B cable to connect the robot to your computer for programming and debugging

tools to help with kit assembly; see the user’s guide for a list of specific tools

Optional accessories

You might also consider getting these for your Romi 32U4 robot:

an 8×2 character LCD

a compatible Raspberry Pi (Model B+ or newer, including Pi 3 Model B and Model A+)

sensors

connectors (headers, jumper wires, etc) for adding those sensors or other peripherals

In addition to the Romi 32U4 Control Board, we have some more basic boards designed to mount onto a Romi chassis:

The Motor Driver and Power Distribution Board for Romi Chassis includes the same motor drivers and power circuit (including 5 V regulator) as the Romi 32U4 Control Board, but offers you flexibility in choosing and connecting your own microcontroller.

The Power Distribution Board for Romi Chassis only includes reverse voltage protection and a pushbutton power switch circuit; it is intended to be a convenient way to access the chassis’s battery power and pass it on to the rest of your electronics.

The Romi 32U4 Control Board uses the same microcontroller and includes many of the same features as some of our other programmable robots and controller boards. Consider these alternatives if you want similar electronics on a different chassis:

The Zumo 32U4 is a smaller tracked robot sized to qualify for Mini Sumo competitions and equipped with appropriate sensors. It is available fully assembled or as a kit.

The A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge shares most of the same functionality as the Romi 32U4 Control Board, including the ability to interface with a Raspberry Pi, but it is a smaller board with a more general-purpose form factor instead of being designed to work with a specific chassis. It is also available in a lower-voltage LV version.

People often buy this product together with:

This power distribution board is designed specifically for the Romi chassis as a convenient way to access the chassis’s battery power and pass that on the rest of the electronics that make up your robot. It has slots for soldering directly to the chassis’s battery contacts offers reverse voltage protection, several power switching options, and easy access to the various power busses. Just add your own motor drivers, microcontroller, and sensors to complete your Romi robot.

This power distribution board is designed specifically for the Romi chassis as a convenient way to access the chassis’s battery power and pass that on to the rest of the electronics that make up your robot. The board features reverse voltage protection and the patented latching circuit from the Pololu pushbutton power switch, providing a compact, solid-state power switch for your robot that can be controlled with a momentary pushbutton: one push turns on power and another push turns it off.

The board has a small pushbutton already installed and offers convenient points for connecting external pushbutton or tactile switches in parallel. It also offers several alternate pushbutton connection options that result in push-on-only or push-off-only operation, and additional inputs enable further power control options like allowing your robot to turn off its own power. Alternatively, the board can be reconfigured to disable the pushbutton circuit and give control to the small installed slide switch.

The board’s power buses are accessible through a set of 0.1″-spaced pins that are compatible with standard 0.1″ male and 0.1″ female headers, and also through a larger set of holes that are compatible with 3.5mm-pitch terminal blocks (you can combine a 2-pin block and a 3-pin block into a single 5-pin block that spans the three power holes and two ground holes).

Two 1/4″ #2-56 screws and two #2-56 nuts are included for mounting the board to the Romi chassis.

Power Distribution Board for Romi Chassis.

Motor Driver and Power Distribution Board for Romi Chassis.

Installation

Power Distribution Board for Romi Chassis with included hardware.

Power Distribution Board for Romi Chassis on a black chassis.

Before installing the power distribution board on a Romi chassis, you should solder any headers, terminal blocks, wires, or other connectors you plan to use on the board (not included). Please read the rest of this page carefully to determine what additional connectors you might want and where they should be installed.

It is possible to remove the board from the chassis later to solder additional connections, and some of the through holes can be soldered through the slots in the chassis while the board is mounted, but soldering beforehand is easier and avoids the risk of inadvertently melting the chassis with your soldering iron.

The four battery terminals should be soldered to the board after it is mounted on the chassis, as described in the chassis assembly instructions. You will be able to remove the board and battery contacts from the chassis as a single piece after soldering.

Once your you have soldered your through-hole connections to the power distribution board, please follow the instructions given in the Pololu Romi Chassis User’s Guide to finish assembling the chassis, mounting the control board, and soldering in the battery contacts. (The diagrams in those instructions show assembly with the larger Romi 32U4 Control Board, but the same steps apply for the smaller power distribution board.)

Power switch circuit

By default, the on-board pushbutton can be used to toggle power: one push turns on power and another turns it off. Alternatively, a separate pushbutton can be connected to the BTNA and BTNB pins and used instead. Multiple pushbuttons can be wired in parallel for multiple control points, and each of the parallel pushbuttons, including the one on the board itself, will be able to turn the switch on or off. The latching circuit performs some button debouncing, but pushbuttons with excessive bouncing (several ms) might not function well with it.

For proper pushbutton operation, the board’s slide switch should be left in its Off position. (Sliding the switch to the On position will cause the board power to latch on, and the switch must be returned to the Off position before the board can be turned off with the pushbutton.)

Alternatively, to disable the pushbutton, you can cut the button jumper labeled Btn Jmp; this transfers control of the board’s power to the on-board slide switch instead. A separate slide or toggle switch can be connected to the GATE pin and used instead.

More advanced control options are available through the button connection pins and four control inputs:

Power distribution

The diagram below shows the layout of the power distribution buses and access points on the board.

VBAT is connected to the battery contact labeled BAT1+ and provides a direct connection to the battery supply. By default, VBAT is the high side of all six of the chassis’s AA battery cells in series, although this can be reconfigured with the battery jumper (see below).

VRP provides access to the battery voltage after reverse-voltage protection.

VSW is the battery voltage after reverse protection and the power switch circuit.

VREG is not connected to anything by default, but along with the adjacent ground and VSW pins, the VREG pins provide a good place to connect an optional voltage regulator. For example, adding a D24V5F5 step-down regulator would make a regulated 5 V supply available for a microcontroller and other electronics on your chassis.

BAT2+ provides access to the high side of two AA cells in series. This can be useful if you reconfigure the board to provide two separate battery supplies as described below.

Battery supply configuration

The power distribution board’s default configuration provides battery power, VBAT, from all six of the chassis’s AA cells in series (nominally about 7.2 V with rechargeable batteries or 9 V with alkaline batteries). However, the board’s battery jumper, labeled Bat Jmp, allows you to reconfigure the battery connections to provide two independent supplies: BAT1, with 4 cells in series (nominally 4.8 V rechargeable or 6 V alkaline), and BAT2, with 2 cells in series (nominally 2.4 V rechargeable or 3 V alkaline). Cutting the connection between the BAT1− and BAT2+ pads separates the two sets of batteries, and using solder to bridge the BAT1− and GND pads establishes a common ground between the two new supplies.

Warning: Do not bridge the BAT1− and GND pads without first disconnecting BAT1− from BAT2+. Failing to do so could create a short circuit across the BAT2 batteries.

Simplified schematic diagram

This schematic is also available as a downloadable pdf (110k pdf).

In addition to the power distribution board, we have a few other boards designed to mount onto a Romi chassis:

The Motor Driver and Power Distribution Board for Romi Chassis adds motor drivers and a more versatile power circuit (including a 5 V switching regulator); just add a microcontroller and sensors to build a Romi robot.

The Romi 32U4 Control Board turns the Romi chassis into an integrated robot platform. In addition to the same motor drivers and power circuit found on the motor driver and power distribution board, the Romi 32U4 board includes an on-board ATmega32U4 microcontroller, a number of other peripherals and sensors, and interfaces for an optional LCD or Raspberry Pi.

People often buy this product together with:

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 38 V and efficiently reduces it to 5 V. The board measures only 0.7″ × 0.8″, but it allows a typical continuous output current of up to 5 A. Typical efficiencies of 85% to 95% make this regulator well suited for high-power applications like powering motors or servos. High efficiencies are maintained at light loads by dynamically changing the switching frequency, and an optional shutdown pin enables a low-power state with a current draw of a few hundred microamps.

The D24V50Fx family of step-down voltage regulators generates lower output voltages from input voltages as high as 38 V. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with typical efficiencies between 85% and 95%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. The available output current is a function of the input voltage and efficiency (see the Typical Efficiency and Output Current section below), but the output current can typically be as high as 5 A.

At light loads, the switching frequency automatically changes to maintain high efficiencies. These regulators have a typical quiescent (no load) current draw of less than 1 mA, and the ENABLE pin can be used to put the boards in a low-power state that reduces the quiescent current to approximately 10 µA to 20 µA per volt on VIN.

The modules have built-in reverse-voltage protection, short-circuit protection, a thermal shutdown feature that helps prevent damage from overheating, a soft-start feature that reduces inrush current, and an under-voltage lockout.

Several different fixed output voltages are available:

Several alternatives are available for this product.

Select from the options below and click “Go” to find a particular version.

Close

Alternatives available with variations in these parameter(s): output voltage Select variant…

The different voltage versions of this regulator all look very similar, so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. This product page applies to all versions of the D24V50Fx family.

For lower-power applications, please consider our D24V25Fx family of step-down voltage regulators; these are slightly smaller, pin-compatible versions of this regulator with typical maximum output current of 2.5 A.

Side-by-side comparison of the 2.5A D24V25Fx (left) and 5A D24V50Fx (right) step-down voltage regulators.

Two larger, higher-power, 5 V versions of this regulator are also available: one with a typical maximum output current of 6 A, and the other with a typical maximum output current of 9 A. The higher-power versions also have a few additional features, like a “power good” signal and the ability to lower their output voltage, and they include optional terminal blocks for easy removable connections.

Input voltage:

4.5 V to 38 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 38 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

4.5 V to 38 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 38 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

Fixed 3.3 V or 5 V (depending on regulator version) with 4% accuracy

Typical maximum continuous output current: 5 A

Integrated reverse-voltage protection, over-current protection, over-temperature shutoff, soft-start, and under-voltage lockout

Typical efficiency of 85% to 95%, depending on input voltage and load; the switching frequency automatically changes at light loads to maintain high efficiencies

Typical no-load quiescent current under 1 mA; can be reduced to 10 µA to 20 µA per volt on VIN by disabling the board* Compact size: 0.7″ × 0.8″ × 0.35″ (17.8 mm × 20.3 mm × 8.8 mm)

Two 0.086″ mounting holes for #2 or M2 screws

Connections

This buck regulator has five connection points for four different connections: enable (EN), input voltage (VIN), 2x ground (GND), and output voltage (VOUT).

The input voltage, VIN, powers the regulator. Voltages between 4.5 V and 38 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 4.5 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for graphs of dropout voltages as a function of the load).

The output voltage, VOUT, is fixed and depends on the regulator version: the D24V50F3 version outputs 3.3 V and the D24V50F5 version outputs 5 V.

The regulator is enabled by default: a 100 kΩ pull-up resistor on the board connects the ENABLE pin to reverse-protected VIN. The ENABLE pin can be driven low (under 0.6 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from ENABLE to VIN and by the reverse-voltage protection circuit, which will draw between 10 µA and 20 µA per volt on VIN when ENABLE is held low. If you do not need this feature, you should leave the ENABLE pin disconnected.

Pololu 5A Step-Down Voltage Regulator D24V50Fx with included hardware.

Pololu 5A Step-Down Voltage Regulator D24V50Fx, bottom view.

The five connection points are labeled on the top of the PCB and are arranged with a 0.1″ spacing for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. Either the included 5×1 straight male header strip or the 5×1 right angle male header strip can be soldered into these holes. For the most compact installation, you can solder wires directly to the board.

Pololu 5A Step-Down Voltage Regulator D24V50Fx, side view.

The board has two 0.086″ mounting holes intended for #2 or M2 screws. The mounting holes are at opposite corners of the board and are separated by 0.53″ horizontally and 0.63″ vertically.

Typical efficiency and output current

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. This family of switching regulators typically has an efficiency of 85% to 95%, though the actual efficiency in a given system depends on input voltage, output voltage, and output current. See the efficiency graph near the bottom of this page for more information.

The maximum achievable output current is typically around 5 A, but this depends on many factors, including the ambient temperature, air flow, heat sinking, and the input and output voltage.

Typical dropout voltage

The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. See the “Details” section below for more information on the dropout voltage for this specific regulator version.

Switching frequency and behavior under light loads

The regulator generally operates at a switching frequency of around 600 kHz, but the frequency drops when encountering a light load to improve efficiency. This could make it harder to filter out noise on the output caused by switching.

The graphs below show the typical efficiency and dropout voltage of the 5 V D24V50F5 regulator as a function of the output current:

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.The over-current limit of the regulator operates on a combination of current and temperature: the current threshold decreases as the regulator temperature goes up. However, there might be some operating points at low input voltages and high output currents (well over 5 A) where the current is just under the limit and the regulator might not shut off before damage occurs. If you are using this regulator in an application where the input voltage is near the lower limit and the load could exceed 5 A for sustained periods (more than five seconds), consider using additional protective components such as fuses or circuit breakers.

People often buy this product together with:

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 36 V and efficiently reduces it to 5 V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.5 A and features reverse voltage protection. Typical efficiencies of 85% to 95% make this regulator well suited for powering moderate loads like sensors or small motors. An optional shutdown pin enables a low-power state with a current draw of around 20 μA to 350 μA, depending on the input voltage, and a power-good output indicates when the regulator cannot adequately maintain the output voltage.

The D24V22Fx family of step-down voltage regulators generates lower output voltages from input voltages as high as 36 V. They are synchronous switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with typical efficiencies of 85% to 95%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. These regulators can typically support continuous output currents of over 2 A, though the actual available output current is a function of the input voltage and efficiency (see the Typical efficiency and output current section below). In general, the available output current is a little higher for the lower-voltage versions than it is for the higher-voltage versions, and it decreases as the input voltage increases.

These regulators have a typical quiescent (no load) current draw of around 1 mA, and an enable pin can be used to put the boards in a low-power state that reduces the quiescent current to approximately 5 µA to 10 µA per volt on VIN.

The modules have built-in reverse-voltage protection, short-circuit protection, a thermal shutdown feature that helps prevent damage from overheating, and a soft-start feature that reduces inrush current.

Several different fixed output voltages are available:

Several alternatives are available for this product.

Select from the options below and click “Go” to find a particular version.

Close

Alternatives available with variations in these parameter(s): output voltage Select variant…

The different voltage versions of this regulator all look very similar, so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. This product page applies to all versions of the D24V22Fx family.

The D24V22Fx family is intended to replace our older D24V25Fx family of step-down voltage regulators. The two designs have the same size and similar current capabilities and input voltage ranges, but they do not have the same pinout and are based on different internal circuits, so there are fundamental differences in operation. In particular, these newer D24V22Fx regulators have much lower dropout voltages and provide a “power good” signal, and the newer design allows for higher output voltages (e.g. 12 V).

Input voltage:

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

Fixed 3.3 V, 5 V, 6 V, 7.5 V, 9 V, or 12 V output (depending on regulator version) with 4% accuracy

Typical maximum continuous output current: >2 A

Typical efficiency of 85% to 95%, depending on input voltage, output voltage, and load

Switching frequency: ~400 kHz

Integrated reverse-voltage protection, over-current protection, over-temperature shutoff, and soft-start

1 mA typical no-load quiescent current; this can be reduced to approximately 5 µA to 10 µA per volt on VIN by disabling the board

“Power good” output indicates when the regulator cannot adequately maintain the output voltage

Compact size: 0.7″ × 0.7″ × 0.31″ (17.8 mm × 17.8 mm × 8 mm)

Two 0.086″ mounting holes for #2 or M2 screws

Connections

These buck regulators have five main connection points for five different electrical nodes: power good (PG), enable (EN), input voltage (VIN), ground (GND), and output voltage (VOUT). The board also features a second ground connection point off the main row of connections that might be convenient for applications where you are soldering wires directly to the board rather than using it in a breadboard.

The input voltage, VIN, powers the regulator. Voltages between 4 V and 36 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 4 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for a graph of dropout voltages as a function of the load).

The output voltage, VOUT, is fixed and depends on the regulator version: the D24V22F3 version outputs 3.3 V, the D24V22F5 version outputs 5 V, the D24V22F6 version outputs 6 V, the D24V22F7 version outputs 7.5 V, the D24V22F9 version outputs 9 V, and the D24V22F12 version outputs 12 V.

The regulator is enabled by default: a 270 kΩ pull-up resistor on the board connects the EN pin to reverse-protected VIN. The EN pin can be driven low (under 1 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from EN to VIN and by the reverse-voltage protection circuit, which altogether will draw between 5 µA and 10 µA per volt on VIN when EN is held low. If you do not need this feature, you should leave the EN pin disconnected.

The “power good” indicator, PG, is an open-drain output that goes low when the regulator’s output voltage falls below around 85% of the nominal voltage and becomes high-impedance when the output voltage rises above around 90%. An external pull-up resistor is required to use this pin.

Pololu Step-Down Voltage Regulator D24V22Fx with included hardware.

Pololu Step-Down Voltage Regulator D24V22Fx, bottom view.

The five main connection points are labeled on the top of the PCB and are arranged with a 0.1″ spacing for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. Either the included 5×1 straight male header strip or the 5×1 right angle male header strip can be soldered into these holes. For the most compact installation, you can solder wires directly to the board.

Pololu Step-Down Voltage Regulator D24V22Fx, side view.

The board has two 0.086″ (2.18 mm) diameter mounting holes intended for #2 or M2 screws. The mounting holes are at opposite corners of the board and are separated by 0.52″ (13.21 mm) both horizontally and vertically. For all the board dimensions, see the dimension diagram (204k pdf).

Typical efficiency and output current

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. This family of switching regulators typically has an efficiency of 85% to 95%, though the actual efficiency in a given system depends on input voltage, output voltage, and output current. See the efficiency graph near the bottom of this page for more information.

The maximum achievable output current is typically over 2 A, but this depends on many factors, including the ambient temperature, air flow, heat sinking, and the input and output voltage.

Typical dropout voltage

The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. See the “Details” section below for more information on the dropout voltage for this specific regulator version.

The graphs below show the typical efficiency and dropout voltage of the 5 V D24V22F5 regulator as a function of the output current:

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.

People often buy this product together with:

This small synchronous switching step-down (or buck) regulator takes an input voltage from 4 V to 36 V and efficiently reduces it to 3.3 V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.6 A and features reverse voltage protection. Typical efficiencies of 85% to 95% make this regulator well suited for powering moderate loads like sensors or small motors. An optional shutdown pin enables a low-power state with a current draw of around 20 μA to 350 μA, depending on the input voltage, and a power-good output indicates when the regulator cannot adequately maintain the output voltage.

The D24V22Fx family of step-down voltage regulators generates lower output voltages from input voltages as high as 36 V. They are synchronous switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with typical efficiencies of 85% to 95%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. These regulators can typically support continuous output currents of over 2 A, though the actual available output current is a function of the input voltage and efficiency (see the Typical efficiency and output current section below). In general, the available output current is a little higher for the lower-voltage versions than it is for the higher-voltage versions, and it decreases as the input voltage increases.

These regulators have a typical quiescent (no load) current draw of around 1 mA, and an enable pin can be used to put the boards in a low-power state that reduces the quiescent current to approximately 5 µA to 10 µA per volt on VIN.

The modules have built-in reverse-voltage protection, short-circuit protection, a thermal shutdown feature that helps prevent damage from overheating, and a soft-start feature that reduces inrush current.

Several different fixed output voltages are available:

Several alternatives are available for this product.

Select from the options below and click “Go” to find a particular version.

Close

Alternatives available with variations in these parameter(s): output voltage Select variant…

The different voltage versions of this regulator all look very similar, so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. This product page applies to all versions of the D24V22Fx family.

The D24V22Fx family is intended to replace our older D24V25Fx family of step-down voltage regulators. The two designs have the same size and similar current capabilities and input voltage ranges, but they do not have the same pinout and are based on different internal circuits, so there are fundamental differences in operation. In particular, these newer D24V22Fx regulators have much lower dropout voltages and provide a “power good” signal, and the newer design allows for higher output voltages (e.g. 12 V).

Input voltage:

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

Fixed 3.3 V, 5 V, 6 V, 7.5 V, 9 V, or 12 V output (depending on regulator version) with 4% accuracy

Typical maximum continuous output current: >2 A

Typical efficiency of 85% to 95%, depending on input voltage, output voltage, and load

Switching frequency: ~400 kHz

Integrated reverse-voltage protection, over-current protection, over-temperature shutoff, and soft-start

1 mA typical no-load quiescent current; this can be reduced to approximately 5 µA to 10 µA per volt on VIN by disabling the board

“Power good” output indicates when the regulator cannot adequately maintain the output voltage

Compact size: 0.7″ × 0.7″ × 0.31″ (17.8 mm × 17.8 mm × 8 mm)

Two 0.086″ mounting holes for #2 or M2 screws

Connections

These buck regulators have five main connection points for five different electrical nodes: power good (PG), enable (EN), input voltage (VIN), ground (GND), and output voltage (VOUT). The board also features a second ground connection point off the main row of connections that might be convenient for applications where you are soldering wires directly to the board rather than using it in a breadboard.

The input voltage, VIN, powers the regulator. Voltages between 4 V and 36 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 4 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for a graph of dropout voltages as a function of the load).

The output voltage, VOUT, is fixed and depends on the regulator version: the D24V22F3 version outputs 3.3 V, the D24V22F5 version outputs 5 V, the D24V22F6 version outputs 6 V, the D24V22F7 version outputs 7.5 V, the D24V22F9 version outputs 9 V, and the D24V22F12 version outputs 12 V.

The regulator is enabled by default: a 270 kΩ pull-up resistor on the board connects the EN pin to reverse-protected VIN. The EN pin can be driven low (under 1 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from EN to VIN and by the reverse-voltage protection circuit, which altogether will draw between 5 µA and 10 µA per volt on VIN when EN is held low. If you do not need this feature, you should leave the EN pin disconnected.

The “power good” indicator, PG, is an open-drain output that goes low when the regulator’s output voltage falls below around 85% of the nominal voltage and becomes high-impedance when the output voltage rises above around 90%. An external pull-up resistor is required to use this pin.

Pololu Step-Down Voltage Regulator D24V22Fx with included hardware.

Pololu Step-Down Voltage Regulator D24V22Fx, bottom view.

The five main connection points are labeled on the top of the PCB and are arranged with a 0.1″ spacing for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. Either the included 5×1 straight male header strip or the 5×1 right angle male header strip can be soldered into these holes. For the most compact installation, you can solder wires directly to the board.

Pololu Step-Down Voltage Regulator D24V22Fx, side view.

The board has two 0.086″ (2.18 mm) diameter mounting holes intended for #2 or M2 screws. The mounting holes are at opposite corners of the board and are separated by 0.52″ (13.21 mm) both horizontally and vertically. For all the board dimensions, see the dimension diagram (204k pdf).

Typical efficiency and output current

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. This family of switching regulators typically has an efficiency of 85% to 95%, though the actual efficiency in a given system depends on input voltage, output voltage, and output current. See the efficiency graph near the bottom of this page for more information.

The maximum achievable output current is typically over 2 A, but this depends on many factors, including the ambient temperature, air flow, heat sinking, and the input and output voltage.

Typical dropout voltage

The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. See the “Details” section below for more information on the dropout voltage for this specific regulator version.

The graph below shows the typical efficiency of the 3.3 V D24V22F3 regulator as a function of the output current:

Since the regulator’s input voltage must be at least 4 V, dropout voltage is not a consideration for this 3.3 V version.

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.

People often buy this product together with:

This compact sonar range finder by Maxbotix detects objects from 0 to 6.45 m (21.2 ft) with a resolution of 2.5 cm (1") for distances beyond 15 cm (6"). Unlike other sonar range finders, the LV-MaxSonar has virtually no dead zone: it can detect even small objects up to and touching the front sensor face!The EZ0, EZ1, EZ2, EZ3, and EZ4 versions have progressively narrower beam angles.

MaxBotix ultrasonic sensor line comparison chart.

The Maxbotix LV-MaxSonar-EZ family of sonar range finders offers very short- to long-range detection and ranging in an incredibly small package with ultra-low power consumption. The LV-MaxSonar-EZ detects objects from 0 to 6.45 meters (21.2 feet) and provides sonar range information beyond 15 cm (6") with a resolution of 2.5 cm resolution (1 in). Objects between 0 and 15 cm range as 15 cm. The sensor provides three output interfaces, all of which are active simultaneously: digital pulse width output, analog voltage output, and asynchronous serial digital output. The LV-MaxSonar is available in five factory-calibrated beam patterns (EZ0-4).

For a higher-resolution, longer-range version, please consider the XL-MaxSonar-EZ and XL-MaxSonar-AE families of distance sensors.

Small and light: 0.870" x 0.785" x 0.645" (2.2 x 2.0 x 1.6 cm), 0.15 oz (4.3 g)

Long range detection: 0 – 6.45 m (21.2 ft)

No dead zone (detections from 0 to 6" are output as 6")

Resolution of 1" (2.5 cm)

Low typical current consumption: 2 mA

Runs on 2.5 – 5.5 V

42 kHz ultrasonic sensor

20 Hz reading rate

Free-run or triggered operation

Three interfaces (all are active simultaneously):

Serial output: asynchronous, logic-level, inverted, 9600 bps 8N1

Analog output: (Vcc/512) / inch (10 mV/inch when input voltage Vcc = 5 V)

Pulse width output: 147 μs/inch

Serial output: asynchronous, logic-level, inverted, 9600 bps 8N1

Analog output: (Vcc/512) / inch (10 mV/inch when input voltage Vcc = 5 V)

Pulse width output: 147 μs/inch

Since there are 15 members of the XL- and LV-MaxSonar acoustic distance sensor family, we recommend using the Maxbotix sonar range finder selection guide when choosing a acoustic range sensor for your application. There are 5 different beam configurations for the LV-MaxSonar family (EZ0 – EZ4), each pictured below.

LV-MaxSonar-EZ beam patterns (range shown on 1-foot grid to various diameter dowels)

Maxbotix LV-MaxSonar-EZ0 MB1000 beam characteristics:

Maxbotix LV-MaxSonar-EZ1 MB1010 beam characteristics:

Maxbotix LV-MaxSonar-EZ2 MB1020 beam characteristics:

Maxbotix LV-MaxSonar-EZ3 MB1030 beam characteristics:

Maxbotix LV-MaxSonar-EZ4 MB1040 beam characteristics:

People often buy this product together with:

This compact sonar range finder by Maxbotix detects objects from 0 to 6.45 m (21.2 ft) with a resolution of 2.5 cm (1") for distances beyond 15 cm (6"). Unlike other sonar range finders, the LV-MaxSonar has virtually no dead zone: it can detect even small objects up to and touching the front sensor face!The EZ0, EZ1, EZ2, EZ3, and EZ4 versions have progressively narrower beam angles.

MaxBotix ultrasonic sensor line comparison chart.

The Maxbotix LV-MaxSonar-EZ family of sonar range finders offers very short- to long-range detection and ranging in an incredibly small package with ultra-low power consumption. The LV-MaxSonar-EZ detects objects from 0 to 6.45 meters (21.2 feet) and provides sonar range information beyond 15 cm (6") with a resolution of 2.5 cm resolution (1 in). Objects between 0 and 15 cm range as 15 cm. The sensor provides three output interfaces, all of which are active simultaneously: digital pulse width output, analog voltage output, and asynchronous serial digital output. The LV-MaxSonar is available in five factory-calibrated beam patterns (EZ0-4).

For a higher-resolution, longer-range version, please consider the XL-MaxSonar-EZ and XL-MaxSonar-AE families of distance sensors.

Small and light: 0.870" x 0.785" x 0.645" (2.2 x 2.0 x 1.6 cm), 0.15 oz (4.3 g)

Long range detection: 0 – 6.45 m (21.2 ft)

No dead zone (detections from 0 to 6" are output as 6")

Resolution of 1" (2.5 cm)

Low typical current consumption: 2 mA

Runs on 2.5 – 5.5 V

42 kHz ultrasonic sensor

20 Hz reading rate

Free-run or triggered operation

Three interfaces (all are active simultaneously):

Serial output: asynchronous, logic-level, inverted, 9600 bps 8N1

Analog output: (Vcc/512) / inch (10 mV/inch when input voltage Vcc = 5 V)

Pulse width output: 147 μs/inch

Serial output: asynchronous, logic-level, inverted, 9600 bps 8N1

Analog output: (Vcc/512) / inch (10 mV/inch when input voltage Vcc = 5 V)

Pulse width output: 147 μs/inch

Since there are 15 members of the XL- and LV-MaxSonar acoustic distance sensor family, we recommend using the Maxbotix sonar range finder selection guide when choosing a acoustic range sensor for your application. There are 5 different beam configurations for the LV-MaxSonar family (EZ0 – EZ4), each pictured below.

LV-MaxSonar-EZ beam patterns (range shown on 1-foot grid to various diameter dowels)

Maxbotix LV-MaxSonar-EZ0 MB1000 beam characteristics:

Maxbotix LV-MaxSonar-EZ1 MB1010 beam characteristics:

Maxbotix LV-MaxSonar-EZ2 MB1020 beam characteristics:

Maxbotix LV-MaxSonar-EZ3 MB1030 beam characteristics:

Maxbotix LV-MaxSonar-EZ4 MB1040 beam characteristics:

People often buy this product together with:

The GP2Y0A60SZ distance sensor from Sharp offers a wide detection range of 4″ to 60″ (10 cm to 150 cm) and a high update rate of 60 Hz. The distance is indicated by an analog voltage, so only a single analog input is required to interface with the module. The sensor ships installed on our compact carrier board, which makes it easy to integrate this great sensor into your project, and is configured for 3V mode.

Pololu Carrier with Sharp GP2Y0A60SZLF Analog Distance Sensor 10-150cm, front view with dimensions.

Sharp’s distance sensors are a popular choice for many projects that require accurate distance measurements. This particular sensor is small and affordable, making it an attractive alternative to sonar rangefinders, while its wide sensing range and resistance to interference from ambient IR set it apart from other IR distance sensors. It consists of a Sharp GP2Y0A60SZLF module installed on our compact carrier board, which includes all of the external components required to make it work and provides a 0.1″ pin spacing that is compatible with standard connectors, solderless breadboards, and perfboards. With an ability to measure distances from as close as four inches to as far as five feet (10 cm to 150 cm), this sensor has the widest range of any of our Sharp distance sensors, and its 60 Hz update rate is more than twice that of Sharp’s older GP2Y0A02YK0F analog distance sensor that has a similar sensing range.

Interfacing to most microcontrollers is straightforward: the single analog output, OUT, can be connected to an analog-to-digital converter for taking distance measurements, or the output can be connected to a comparator for threshold detection. The sensor automatically updates the output approximately every 16 ms. The enable pin, EN, can be driven low to disable the IR emitter and put the sensor into a low-current stand-by mode. This pin is pulled high on the carrier board through a 10 kΩ pull-up resistor to enable the sensor by default.

A 1×4 strip of 0.1″ header pins and a 1×4 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards, or you can solder wires directly to the board itself for more compact installations. The board features one 0.125″ mounting hole that works with #4 or M3 screws (not included); if you do not need the mounting hole, you can cut that part of the board off to reduce its size.

The GP2Y0A60SZ supports two operating modes: 5V and 3V. In 5V mode, the recommended operating voltage is 2.7 V to 5.5 V, and the output voltage differential over the full distance range is approximately 3 V, varying from around 3.6 V at 10 cm to 0.6 V at 150 cm. In 3V mode, the recommended operating voltage is 2.7 V to 3.6 V, and the output voltage differential over the full distance range is approximately 1.6 V, varying from around 1.9 V at 10 cm to 0.3 V at 150 cm. The GP2Y0A60SZ datasheet (701k pdf) contains a plot of analog output voltage as a function of the distance for the two modes.

Our GP2Y0A60 carrier board is available configured for 5V mode or configured for 3V mode:

The only difference between the two versions is the presence or absence of a zero ohm resistor as shown in the picture above (the component location is marked by a rectangle on the silkscreen). You can convert a 5V version to 3V by removing the resistor, and you can convert a 3V version to 5V by shorting across the two pads.

Note that the 5V version can be powered all the way down to 2.7 V, and the relationship between the sensor output voltage and distance is mostly independent of the supply voltage. The main drawback to powering the 5V version at a lower voltage is the output voltage will not exceed the supply voltage, so the effective minimum detection distance might increase (i.e. for distances that would result in output voltages above your supply voltage, the output will instead be capped at the supply voltage). On the other hand, if you mostly care about measuring distances closer to the maximum end of the range, you could benefit from the increased output voltage differential of the 5V version even if you are only powering it at 3.3 V.

Operating voltage:

5V version: 2.7 V to 5.5 V

3V version: 2.7 V to 3.6 V

5V version: 2.7 V to 5.5 V

3V version: 2.7 V to 3.6 V

Average current consumption: 33 mA (typical)

Distance measuring range: 10 cm to 150 cm (4″ to 60″)

Output type: analog voltage

Output voltage differential over distance range:

5V version: 3.0 V (typical)

3V version: 1.6 V (typical)

5V version: 3.0 V (typical)

3V version: 1.6 V (typical)

Update period: 16.5 ± 4 ms

Enable pin can optionally be used to disable the emitter and save power

Size without header pins: 33 mm × 10.4 mm × 10.2 mm (1.3″ × 0.41″ × 0.4″)

Weight without header pins: 2.5 g (0.09 oz)

The above schematic shows the additional components the carrier board incorporates to make the GP2Y0A60SZLF easier to use. This schematic is also available as a downloadable pdf (142k pdf).

We carry several other Sharp distance sensors, including the shorter range Sharp GP2Y0A41SK0F analog distance sensor (4 – 30 cm) and Sharp GP2Y0A21YK0F analog distance sensor (10 – 80 cm). With regard to performance, this GP2Y0A60SZ is most similar to the Sharp GP2Y0A02YK0F analog distance sensor (20 – 150 cm), but the GP2Y0A60SZ offers a lower minimum detection distance and more than twice the sampling rate in a much smaller package:

Sharp GP2Y0A02YK0F Sensor 20-150cm (left) next to Pololu Carrier with Sharp GP2Y0A60SZLF Sensor 10-150cm (right).

We also carry three digital Sharp distance sensors that have lower minimum detection distances, quicker response times, lower current draws, and much smaller packages; they are available with a 5 cm, 10 cm, or 15 cm maximum detection distance and simply tell you if something is in their detection range, not how far away it is.

A variety of Sharp distance sensors.

People often buy this product together with:

This small digital distance sensor detects objects between 0.5 cm and 15 cm (0.2″ and 6″) away. With its quick response time, small size, low current draw, and short minimum sensing distance, this sensor is a good choice for non-contact, close-proximity object detection, and our compact carrier PCB makes it easy to integrate into your project.

These sensors are a great way to quickly detect the presence of nearby objects. It consists of a Sharp GP2Y0D805, GP2Y0D810, or GP2Y0D815 sensor module installed on our tiny carrier board for these sensors, which includes all of the external components required to make them work. The available versions offer three different sensing ranges:

Carrier with GP2Y0D805Z0F: 0.5 cm to 5 cm

Carrier with GP2Y0D810Z0F: 2 cm to 10 cm

Carrier with GP2Y0D815Z0F: 0.5 cm to 15 cm

There are a few millimeters of hysteresis around the maximum range threshold and no hysteresis at the minimum range threshold. Note that these sensors will only tell you if there is an object within the detection range along their narrow lines of sight; they will not tell you how far away the object is.

With detection distances up to 150 mm and a typical sampling rate of almost 400 Hz, these sensors provides an attractive alternative to shorter-range LED-phototransistor reflectance pairs and longer-range but slower sensors such as the Sharp GP2Y0A41SK0F analog distance sensor. The output, Vo, is driven low when the sensor detects an object; otherwise, the output is high.

Sharp GP2Y0D805Z0F digital distance sensor 5 cm measuring characteristics.

Sharp GP2Y0D810Z0F digital distance sensor 10 cm measuring characteristics.

Sharp GP2Y0D815Z0F digital distance sensor 15 cm measuring characteristics.

Some example applications include:

break-beam sensor or photogate alternative

non-contact bumper or obstacle detector

a counter or timer of objects as they pass by

The Pololu carrier board lets you interface with the GP2Y0D805, GP2Y0D810, or GP2Y0D815 sensor using a three-pin 0.1″ connector, such as the included 3×1 straight male header strip and 3×1 right-angle male header strip. You can connect to these pins with a servo cable or with a custom-made cable using pre-crimped wires and a 3×1 crimp connector housing.

The square pad is ground, the middle pad is VIN (2.7 – 6.2 V), and the remaining pad is the sensor output, OUT. Depending on your power source, you might notice an increase in performance by placing a large (>10 uF) capacitor between power and ground somewhere near the sensor.

A red LED on the back of the PCB lights when the output is low, indicating that the sensor is detecting something. With the LED in the circuit, the low output signal will be around 1 V. If so desired, you can disable this LED by cutting the trace between it and the OUT pin where it is marked on the silkscreen or by desoldering the LED, in which case the low voltage will be below 0.6 V.

The GP2Y0D805, GP2Y0D810, and GP2Y0D815 have an optional enable input that can be used to put the sensor into low-power mode. The Pololu carrier board connects this input to Vcc so that the sensor is always enabled, but you can solder a wire to the pad labeled “enable” on the back of the PCB if you want control over this input. Note that you will need to cut the trace that connects the enable line to Vcc on the PCB if you want to be able to disable the sensor. This trace is marked on the silkscreen, and there is a caret that indicates where we suggest you make the cut.

The carrier board has a 0.086″ mounting hole for a #2 or M2 screw. You can make the module more compact by cutting or grinding off this portion of the PCB if you do not need the mounting hole.

Operating voltage: 2.7 V to 6.2 V

Average current consumption: 5 mA (typical)

Distance measuring range

GP2Y0D805Z0F: 0.5 cm to 5 cm (0.2″ to 2″)

GP2Y0D810Z0F: 2 cm to 10 cm (0.8″ to 4″)

GP2Y0D815Z0F: 0.5 cm to 5 cm (0.2″ to 6″)

GP2Y0D805Z0F: 0.5 cm to 5 cm (0.2″ to 2″)

GP2Y0D810Z0F: 2 cm to 10 cm (0.8″ to 4″)

GP2Y0D815Z0F: 0.5 cm to 5 cm (0.2″ to 6″)

Output type: digital signal (low when detecting an object, high otherwise)

Steady state update period: 2.56 ms typical (3.77 ms max)

Enable pad can optionally be used to disable the emitter and save power (this feature requires you to cut a trace first)

Size without header pins: 21.6 mm × 8.9 mm × 10.4 mm (0.85″ × 0.35″ × 0.41″)

Weight without header pins: 1.5 g (0.05 oz)

Pololu carrier for Sharp GP2Y0D805Z0F, GP2Y0D810Z0F, and GP2Y0D815Z0F sensors schematic diagram.

We carry several analog Sharp distance sensors as well: the Sharp GP2Y0A51SK0F 2 – 15 cm, the Sharp GP2Y0A41SK0F 4 – 30 cm, the Sharp GP2Y0A21YK0F 10 – 80 cm, and the Sharp GP2Y0A02YK0F 20 – 150 cm. These analog distance sensors have longer minimum detection distances and much slower response times than the GP2Y0D805, GP2Y0D810, and GP2Y0D815, but they can see farther and report the distance to the detected object rather than simply if an object is detected.

A variety of Sharp distance sensors. From left to right: GP2Y0A02, GP2Y0A21 or GP2Y0A41, GP2Y0A51, and GP2Y0D8xx.

We also carry the newer Sharp GP2Y0A60SZ analog distance sensor (10 – 150 cm), which outperforms the other analog Sharp distance sensors in almost all respects, offering a low minimum detection distance, high maximum detection distance, wide 3 V output voltage differential, high 60 Hz sampling rate, operation down to 2.7 V, and optional enable control, all in a smaller package.

Sharp GP2Y0A02YK0F Sensor 20-150cm (left) next to Pololu Carrier with Sharp GP2Y0A60SZLF Sensor 10-150cm (right).

Note: This product comes with the GP2Y0D805Z0F, GP2Y0D810Z0F, or GP2Y0D815Z0F soldered into the carrier PCB. We sell the sensor modules by themselves, and we sell the carrier PCB without the sensor for those who already have the sensor or who want to solder the board together personally.

People often buy this product together with:

This small digital distance sensor detects objects between 0.5 cm and 5 cm (0.2″ and 2″) away. With its quick response time, small size, low current draw, and short minimum sensing distance, this sensor is a good choice for non-contact, close-proximity object detection, and our compact carrier PCB makes it easy to integrate into your project.

These sensors are a great way to quickly detect the presence of nearby objects. It consists of a Sharp GP2Y0D805, GP2Y0D810, or GP2Y0D815 sensor module installed on our tiny carrier board for these sensors, which includes all of the external components required to make them work. The available versions offer three different sensing ranges:

Carrier with GP2Y0D805Z0F: 0.5 cm to 5 cm

Carrier with GP2Y0D810Z0F: 2 cm to 10 cm

Carrier with GP2Y0D815Z0F: 0.5 cm to 15 cm

There are a few millimeters of hysteresis around the maximum range threshold and no hysteresis at the minimum range threshold. Note that these sensors will only tell you if there is an object within the detection range along their narrow lines of sight; they will not tell you how far away the object is.

With detection distances up to 150 mm and a typical sampling rate of almost 400 Hz, these sensors provides an attractive alternative to shorter-range LED-phototransistor reflectance pairs and longer-range but slower sensors such as the Sharp GP2Y0A41SK0F analog distance sensor. The output, Vo, is driven low when the sensor detects an object; otherwise, the output is high.

Sharp GP2Y0D805Z0F digital distance sensor 5 cm measuring characteristics.

Sharp GP2Y0D810Z0F digital distance sensor 10 cm measuring characteristics.

Sharp GP2Y0D815Z0F digital distance sensor 15 cm measuring characteristics.

Some example applications include:

break-beam sensor or photogate alternative

non-contact bumper or obstacle detector

a counter or timer of objects as they pass by

The Pololu carrier board lets you interface with the GP2Y0D805, GP2Y0D810, or GP2Y0D815 sensor using a three-pin 0.1″ connector, such as the included 3×1 straight male header strip and 3×1 right-angle male header strip. You can connect to these pins with a servo cable or with a custom-made cable using pre-crimped wires and a 3×1 crimp connector housing.

The square pad is ground, the middle pad is VIN (2.7 – 6.2 V), and the remaining pad is the sensor output, OUT. Depending on your power source, you might notice an increase in performance by placing a large (>10 uF) capacitor between power and ground somewhere near the sensor.

A red LED on the back of the PCB lights when the output is low, indicating that the sensor is detecting something. With the LED in the circuit, the low output signal will be around 1 V. If so desired, you can disable this LED by cutting the trace between it and the OUT pin where it is marked on the silkscreen or by desoldering the LED, in which case the low voltage will be below 0.6 V.

The GP2Y0D805, GP2Y0D810, and GP2Y0D815 have an optional enable input that can be used to put the sensor into low-power mode. The Pololu carrier board connects this input to Vcc so that the sensor is always enabled, but you can solder a wire to the pad labeled “enable” on the back of the PCB if you want control over this input. Note that you will need to cut the trace that connects the enable line to Vcc on the PCB if you want to be able to disable the sensor. This trace is marked on the silkscreen, and there is a caret that indicates where we suggest you make the cut.

The carrier board has a 0.086″ mounting hole for a #2 or M2 screw. You can make the module more compact by cutting or grinding off this portion of the PCB if you do not need the mounting hole.

Operating voltage: 2.7 V to 6.2 V

Average current consumption: 5 mA (typical)

Distance measuring range

GP2Y0D805Z0F: 0.5 cm to 5 cm (0.2″ to 2″)

GP2Y0D810Z0F: 2 cm to 10 cm (0.8″ to 4″)

GP2Y0D815Z0F: 0.5 cm to 5 cm (0.2″ to 6″)

GP2Y0D805Z0F: 0.5 cm to 5 cm (0.2″ to 2″)

GP2Y0D810Z0F: 2 cm to 10 cm (0.8″ to 4″)

GP2Y0D815Z0F: 0.5 cm to 5 cm (0.2″ to 6″)

Output type: digital signal (low when detecting an object, high otherwise)

Steady state update period: 2.56 ms typical (3.77 ms max)

Enable pad can optionally be used to disable the emitter and save power (this feature requires you to cut a trace first)

Size without header pins: 21.6 mm × 8.9 mm × 10.4 mm (0.85″ × 0.35″ × 0.41″)

Weight without header pins: 1.5 g (0.05 oz)

Pololu carrier for Sharp GP2Y0D805Z0F, GP2Y0D810Z0F, and GP2Y0D815Z0F sensors schematic diagram.

We carry several analog Sharp distance sensors as well: the Sharp GP2Y0A51SK0F 2 – 15 cm, the Sharp GP2Y0A41SK0F 4 – 30 cm, the Sharp GP2Y0A21YK0F 10 – 80 cm, and the Sharp GP2Y0A02YK0F 20 – 150 cm. These analog distance sensors have longer minimum detection distances and much slower response times than the GP2Y0D805, GP2Y0D810, and GP2Y0D815, but they can see farther and report the distance to the detected object rather than simply if an object is detected.

A variety of Sharp distance sensors. From left to right: GP2Y0A02, GP2Y0A21 or GP2Y0A41, GP2Y0A51, and GP2Y0D8xx.

We also carry the newer Sharp GP2Y0A60SZ analog distance sensor (10 – 150 cm), which outperforms the other analog Sharp distance sensors in almost all respects, offering a low minimum detection distance, high maximum detection distance, wide 3 V output voltage differential, high 60 Hz sampling rate, operation down to 2.7 V, and optional enable control, all in a smaller package.

Sharp GP2Y0A02YK0F Sensor 20-150cm (left) next to Pololu Carrier with Sharp GP2Y0A60SZLF Sensor 10-150cm (right).

Note: This product comes with the GP2Y0D805Z0F, GP2Y0D810Z0F, or GP2Y0D815Z0F soldered into the carrier PCB. We sell the sensor modules by themselves, and we sell the carrier PCB without the sensor for those who already have the sensor or who want to solder the board together personally.

People often buy this product together with:

This small digital distance sensor detects objects between 2 cm and 10 cm (0.8″ and 4″) away. With its quick response time, small size, and low current draw, this sensor is a good choice for non-contact object detection, and our compact carrier PCB makes it easy to integrate into your project.

These sensors are a great way to quickly detect the presence of nearby objects. It consists of a Sharp GP2Y0D805, GP2Y0D810, or GP2Y0D815 sensor module installed on our tiny carrier board for these sensors, which includes all of the external components required to make them work. The available versions offer three different sensing ranges:

Carrier with GP2Y0D805Z0F: 0.5 cm to 5 cm

Carrier with GP2Y0D810Z0F: 2 cm to 10 cm

Carrier with GP2Y0D815Z0F: 0.5 cm to 15 cm

There are a few millimeters of hysteresis around the maximum range threshold and no hysteresis at the minimum range threshold. Note that these sensors will only tell you if there is an object within the detection range along their narrow lines of sight; they will not tell you how far away the object is.

With detection distances up to 150 mm and a typical sampling rate of almost 400 Hz, these sensors provides an attractive alternative to shorter-range LED-phototransistor reflectance pairs and longer-range but slower sensors such as the Sharp GP2Y0A41SK0F analog distance sensor. The output, Vo, is driven low when the sensor detects an object; otherwise, the output is high.

Sharp GP2Y0D805Z0F digital distance sensor 5 cm measuring characteristics.

Sharp GP2Y0D810Z0F digital distance sensor 10 cm measuring characteristics.

Sharp GP2Y0D815Z0F digital distance sensor 15 cm measuring characteristics.

Some example applications include:

break-beam sensor or photogate alternative

non-contact bumper or obstacle detector

a counter or timer of objects as they pass by

The Pololu carrier board lets you interface with the GP2Y0D805, GP2Y0D810, or GP2Y0D815 sensor using a three-pin 0.1″ connector, such as the included 3×1 straight male header strip and 3×1 right-angle male header strip. You can connect to these pins with a servo cable or with a custom-made cable using pre-crimped wires and a 3×1 crimp connector housing.

The square pad is ground, the middle pad is VIN (2.7 – 6.2 V), and the remaining pad is the sensor output, OUT. Depending on your power source, you might notice an increase in performance by placing a large (>10 uF) capacitor between power and ground somewhere near the sensor.

A red LED on the back of the PCB lights when the output is low, indicating that the sensor is detecting something. With the LED in the circuit, the low output signal will be around 1 V. If so desired, you can disable this LED by cutting the trace between it and the OUT pin where it is marked on the silkscreen or by desoldering the LED, in which case the low voltage will be below 0.6 V.

The GP2Y0D805, GP2Y0D810, and GP2Y0D815 have an optional enable input that can be used to put the sensor into low-power mode. The Pololu carrier board connects this input to Vcc so that the sensor is always enabled, but you can solder a wire to the pad labeled “enable” on the back of the PCB if you want control over this input. Note that you will need to cut the trace that connects the enable line to Vcc on the PCB if you want to be able to disable the sensor. This trace is marked on the silkscreen, and there is a caret that indicates where we suggest you make the cut.

The carrier board has a 0.086″ mounting hole for a #2 or M2 screw. You can make the module more compact by cutting or grinding off this portion of the PCB if you do not need the mounting hole.

Operating voltage: 2.7 V to 6.2 V

Average current consumption: 5 mA (typical)

Distance measuring range

GP2Y0D805Z0F: 0.5 cm to 5 cm (0.2″ to 2″)

GP2Y0D810Z0F: 2 cm to 10 cm (0.8″ to 4″)

GP2Y0D815Z0F: 0.5 cm to 5 cm (0.2″ to 6″)

GP2Y0D805Z0F: 0.5 cm to 5 cm (0.2″ to 2″)

GP2Y0D810Z0F: 2 cm to 10 cm (0.8″ to 4″)

GP2Y0D815Z0F: 0.5 cm to 5 cm (0.2″ to 6″)

Output type: digital signal (low when detecting an object, high otherwise)

Steady state update period: 2.56 ms typical (3.77 ms max)

Enable pad can optionally be used to disable the emitter and save power (this feature requires you to cut a trace first)

Size without header pins: 21.6 mm × 8.9 mm × 10.4 mm (0.85″ × 0.35″ × 0.41″)

Weight without header pins: 1.5 g (0.05 oz)

Pololu carrier for Sharp GP2Y0D805Z0F, GP2Y0D810Z0F, and GP2Y0D815Z0F sensors schematic diagram.

We carry several analog Sharp distance sensors as well: the Sharp GP2Y0A51SK0F 2 – 15 cm, the Sharp GP2Y0A41SK0F 4 – 30 cm, the Sharp GP2Y0A21YK0F 10 – 80 cm, and the Sharp GP2Y0A02YK0F 20 – 150 cm. These analog distance sensors have longer minimum detection distances and much slower response times than the GP2Y0D805, GP2Y0D810, and GP2Y0D815, but they can see farther and report the distance to the detected object rather than simply if an object is detected.

A variety of Sharp distance sensors. From left to right: GP2Y0A02, GP2Y0A21 or GP2Y0A41, GP2Y0A51, and GP2Y0D8xx.

We also carry the newer Sharp GP2Y0A60SZ analog distance sensor (10 – 150 cm), which outperforms the other analog Sharp distance sensors in almost all respects, offering a low minimum detection distance, high maximum detection distance, wide 3 V output voltage differential, high 60 Hz sampling rate, operation down to 2.7 V, and optional enable control, all in a smaller package.

Sharp GP2Y0A02YK0F Sensor 20-150cm (left) next to Pololu Carrier with Sharp GP2Y0A60SZLF Sensor 10-150cm (right).

Note: This product comes with the GP2Y0D805Z0F, GP2Y0D810Z0F, or GP2Y0D815Z0F soldered into the carrier PCB. We sell the sensor modules by themselves, and we sell the carrier PCB without the sensor for those who already have the sensor or who want to solder the board together personally.

People often buy this product together with:

The GP2Y0A60SZ distance sensor from Sharp offers a wide detection range of 4″ to 60″ (10 cm to 150 cm) and a high update rate of 60 Hz. The distance is indicated by an analog voltage, so only a single analog input is required to interface with the module. The sensor ships installed on our compact carrier board, which makes it easy to integrate this great sensor into your project, and is configured for 5V mode.

Pololu Carrier with Sharp GP2Y0A60SZLF Analog Distance Sensor 10-150cm, front view with dimensions.

Sharp’s distance sensors are a popular choice for many projects that require accurate distance measurements. This particular sensor is small and affordable, making it an attractive alternative to sonar rangefinders, while its wide sensing range and resistance to interference from ambient IR set it apart from other IR distance sensors. It consists of a Sharp GP2Y0A60SZLF module installed on our compact carrier board, which includes all of the external components required to make it work and provides a 0.1″ pin spacing that is compatible with standard connectors, solderless breadboards, and perfboards. With an ability to measure distances from as close as four inches to as far as five feet (10 cm to 150 cm), this sensor has the widest range of any of our Sharp distance sensors, and its 60 Hz update rate is more than twice that of Sharp’s older GP2Y0A02YK0F analog distance sensor that has a similar sensing range.

Interfacing to most microcontrollers is straightforward: the single analog output, OUT, can be connected to an analog-to-digital converter for taking distance measurements, or the output can be connected to a comparator for threshold detection. The sensor automatically updates the output approximately every 16 ms. The enable pin, EN, can be driven low to disable the IR emitter and put the sensor into a low-current stand-by mode. This pin is pulled high on the carrier board through a 10 kΩ pull-up resistor to enable the sensor by default.

A 1×4 strip of 0.1″ header pins and a 1×4 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards, or you can solder wires directly to the board itself for more compact installations. The board features one 0.125″ mounting hole that works with #4 or M3 screws (not included); if you do not need the mounting hole, you can cut that part of the board off to reduce its size.

The GP2Y0A60SZ supports two operating modes: 5V and 3V. In 5V mode, the recommended operating voltage is 2.7 V to 5.5 V, and the output voltage differential over the full distance range is approximately 3 V, varying from around 3.6 V at 10 cm to 0.6 V at 150 cm. In 3V mode, the recommended operating voltage is 2.7 V to 3.6 V, and the output voltage differential over the full distance range is approximately 1.6 V, varying from around 1.9 V at 10 cm to 0.3 V at 150 cm. The GP2Y0A60SZ datasheet (701k pdf) contains a plot of analog output voltage as a function of the distance for the two modes.

Our GP2Y0A60 carrier board is available configured for 5V mode or configured for 3V mode:

The only difference between the two versions is the presence or absence of a zero ohm resistor as shown in the picture above (the component location is marked by a rectangle on the silkscreen). You can convert a 5V version to 3V by removing the resistor, and you can convert a 3V version to 5V by shorting across the two pads.

Note that the 5V version can be powered all the way down to 2.7 V, and the relationship between the sensor output voltage and distance is mostly independent of the supply voltage. The main drawback to powering the 5V version at a lower voltage is the output voltage will not exceed the supply voltage, so the effective minimum detection distance might increase (i.e. for distances that would result in output voltages above your supply voltage, the output will instead be capped at the supply voltage). On the other hand, if you mostly care about measuring distances closer to the maximum end of the range, you could benefit from the increased output voltage differential of the 5V version even if you are only powering it at 3.3 V.

Operating voltage:

5V version: 2.7 V to 5.5 V

3V version: 2.7 V to 3.6 V

5V version: 2.7 V to 5.5 V

3V version: 2.7 V to 3.6 V

Average current consumption: 33 mA (typical)

Distance measuring range: 10 cm to 150 cm (4″ to 60″)

Output type: analog voltage

Output voltage differential over distance range:

5V version: 3.0 V (typical)

3V version: 1.6 V (typical)

5V version: 3.0 V (typical)

3V version: 1.6 V (typical)

Update period: 16.5 ± 4 ms

Enable pin can optionally be used to disable the emitter and save power

Size without header pins: 33 mm × 10.4 mm × 10.2 mm (1.3″ × 0.41″ × 0.4″)

Weight without header pins: 2.5 g (0.09 oz)

The above schematic shows the additional components the carrier board incorporates to make the GP2Y0A60SZLF easier to use. This schematic is also available as a downloadable pdf (142k pdf).

We carry several other Sharp distance sensors, including the shorter range Sharp GP2Y0A41SK0F analog distance sensor (4 – 30 cm) and Sharp GP2Y0A21YK0F analog distance sensor (10 – 80 cm). With regard to performance, this GP2Y0A60SZ is most similar to the Sharp GP2Y0A02YK0F analog distance sensor (20 – 150 cm), but the GP2Y0A60SZ offers a lower minimum detection distance and more than twice the sampling rate in a much smaller package:

Sharp GP2Y0A02YK0F Sensor 20-150cm (left) next to Pololu Carrier with Sharp GP2Y0A60SZLF Sensor 10-150cm (right).

We also carry three digital Sharp distance sensors that have lower minimum detection distances, quicker response times, lower current draws, and much smaller packages; they are available with a 5 cm, 10 cm, or 15 cm maximum detection distance and simply tell you if something is in their detection range, not how far away it is.

A variety of Sharp distance sensors.

People often buy this product together with:

The Pololu AltIMU-10 v5 is an inertial measurement unit (IMU) and altimeter that features the same LSM6DS33 gyro and accelerometer and LIS3MDL magnetometer as the MinIMU-9 v5, and adds an LPS25H digital barometer. An I²C interface accesses ten independent pressure, rotation, acceleration, and magnetic measurements that can be used to calculate the sensor’s altitude and absolute orientation. The board operates from 2.5 to 5.5 V and has a 0.1″ pin spacing.

The Pololu AltIMU-10 v5 is a compact (1.0″ × 0.5″) board that combines ST’s LSM6DS33 3-axis gyroscope and 3-axis accelerometer, LIS3MDL 3-axis magnetometer, and LPS25H digital barometer to form an inertial measurement unit (IMU) and altimeter; we therefore recommend careful reading of the LSM6DS33 datasheet (1MB pdf), LIS3MDL datasheet (2MB pdf), and LPS25H datasheet (1MB pdf) before using this product. These sensors are great ICs, but their small packages make them difficult for the typical student or hobbyist to use. They also operate at voltages below 3.6 V, which can make interfacing difficult for microcontrollers operating at 5 V. The AltIMU-10 v5 addresses these issues by incorporating additional electronics, including a voltage regulator and a level-shifting circuit, while keeping the overall size as compact as possible. The board ships fully populated with its SMD components, including the LSM6DS33, LIS3MDL, and LPS25H, as shown in the product picture.

Compared to the previous AltIMU-10 v4, the v5 version uses newer MEMS sensors that provide some increases in accuracy (lower noise and zero-rate offsets). The AltIMU-10 v5 is pin-compatible with the AltIMU-10 v4, but because it uses different sensor chips, software written for older IMU versions will need to be changed to work with the v5.

The AltIMU-10 v5 is also pin-compatible with the MinIMU-9 v5 and offers the same functionality augmented by a digital barometer that can be used to obtain pressure and altitude measurements. It includes a second mounting hole and is only 0.2″ longer than the MinIMU-9 v5. Any code written for the MinIMU-9 v5 should also work with the AltIMU-10 v5.

Side-by-side comparison of the MinIMU-9 v5 with the AltIMU-10 v5.

The LSM6DS33, LIS3MDL, and LPS25H have many configurable options, including dynamically selectable sensitivities for the gyro, accelerometer, and magnetometer and selectable resolutions for the barometer. Each sensor also has a choice of output data rates. The three ICs can be accessed through a shared I²C/TWI interface, allowing the sensors to be addressed individually via a single clock line and a single data line. Additionally, a slave address configuration pin allows users to change the sensors’ I²C addresses and have two AltIMUs connected on the same I²C bus. (For additional information, see the I²C Communication section below.)

The nine independent rotation, acceleration, and magnetic readings provide all the data needed to make an attitude and heading reference system (AHRS), and readings from the absolute pressure sensor can be easily converted to altitudes, giving you a total of ten independent measurements (sometimes called 10DOF). With an appropriate algorithm, a microcontroller or computer can use the data to calculate the orientation and height of the AltIMU board. The gyro can be used to very accurately track rotation on a short timescale, while the accelerometer and compass can help compensate for gyro drift over time by providing an absolute frame of reference. The respective axes of the two chips are aligned on the board to facilitate these sensor fusion calculations. (For an example of such a system using an Arduino, see the picture below and the Sample Code section at the bottom of this page.)

Visualization of AHRS orientation calculated from MinIMU-9 readings.

The carrier board includes a low-dropout linear voltage regulator that provides the 3.3 V required by the LSM6DS33, LIS3MDL, and LPS25H, allowing the module to be powered from a single 2.5 V to 5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 5 V systems. The board’s 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

Specifications

Dimensions: 1.0″ × 0.5″ × 0.1″ (25 mm × 13 mm × 3 mm)

Weight without header pins: 0.8 g (0.03 oz)

Operating voltage: 2.5 V to 5.5 V

Supply current: 5 mA

Output format (I²C):

Gyro: one 16-bit reading per axis

Accelerometer: one 16-bit reading per axis

Magnetometer: one 16-bit reading per axis

Barometer: 24-bit pressure reading (4096 LSb/mbar)

Gyro: one 16-bit reading per axis

Accelerometer: one 16-bit reading per axis

Magnetometer: one 16-bit reading per axis

Barometer: 24-bit pressure reading (4096 LSb/mbar)

Sensitivity range:

Gyro: ±125, ±245, ±500, ±1000, or ±2000°/s

Accelerometer: ±2, ±4, ±8, or ±16 g

Magnetometer: ±4, ±8, ±12, or ±16 gauss

Barometer: 260 mbar to 1260 mbar (26 kPa to 126 kPa)

Gyro: ±125, ±245, ±500, ±1000, or ±2000°/s

Accelerometer: ±2, ±4, ±8, or ±16 g

Magnetometer: ±4, ±8, ±12, or ±16 gauss

Barometer: 260 mbar to 1260 mbar (26 kPa to 126 kPa)

Included Components

A 1×6 strip of 0.1″ header pins and a 1×5 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards or solder wires directly to the board itself for more compact installations. The board features two mounting holes that work with #2 or M2 screws (not included).

Connections

A minimum of four connections is necessary to use the AltIMU-10 v5: VIN, GND, SCL, and SDA. VIN should be connected to a 2.5 V to 5.5 V source, GND to 0 volts, and SCL and SDA should be connected to an I²C bus operating at the same logic level as VIN. (Alternatively, if you are using the board with a 3.3 V system, you can leave VIN disconnected and bypass the built-in regulator by connecting 3.3 V directly to VDD.)

Pololu AltIMU-10 v5 gyro, accelerometer, compass, and altimeter pinout.

Two Pololu AltIMU-10 v5 modules in a breadboard.

Pinout

The CS, data ready, and interrupt pins of the LSM6DS33, LIS3MDL, and LPS25H are not accessible on the AltIMU-10 v5. In particular, the absence of the CS pin means that the optional SPI interface of these ICs is not available. If you want these features, consider using our LSM6DS33 carrier, LIS3MDL carrier, and LPS25H carrier boards.

Schematic Diagram

The above schematic shows the additional components the carrier board incorporates to make the LSM6DS33, LIS3MDL, and LPS25H easier to use, including the voltage regulator that allows the board to be powered from a single 2.5 V to 5.5 V supply and the level-shifter circuit that allows for I²C communication at the same logic voltage level as VIN. This schematic is also available as a downloadable pdf: AltIMU-10 v5 schematic (119k pdf).

I²C Communication

The LSM6DS33’s gyro and accelerometer, the LIS3MDL’s magnetometer, and the LPS25H’s barometer can be queried and configured through the I²C bus. Each of the four sensors acts as a slave device on the same I²C bus (i.e. their clock and data lines are tied together to ease communication). Additionally, level shifters on the I²C clock (SCL) and data lines (SDA) enable I²C communication with microcontrollers operating at the same voltage as VIN (2.5 V to 5.5 V). A detailed explanation of the protocols used by each device can be found in the LSM6DS33 datasheet (1MB pdf), the LIS3MDL datasheet (2MB pdf), and the LPS25H datasheet (1MB pdf). More detailed information about I²C in general can be found in NXP’s I²C-bus specification (1MB pdf).

The LSM6DS33, LIS3MDL, and LPS25H each have separate slave addresses on the I²C bus. The board connects the slave address select pins (SA0 or SA1) of the three ICs together and pulls them all to VDD through a 10 kΩ resistor. You can drive the pin labeled SA0 low to change the slave address. This allows you to have two AltIMUs (or an AltIMU v5 and a MinIMU v5) connected on the same I²C bus. The following table shows the slave addresses of the sensors:

All three chips on the AltIMU-10 v5 are compliant with fast mode (400 kHz) I²C standards as well as with the normal mode.

We have written a basic LSM6DS33 Arduino library, LIS3MDL Arduino library, and LPS25H Arduino library that make it easy to interface the AltIMU-10 v5 with an Arduino or Arduino-compatible board like an A-Star. They also make it simple to configure the sensors and read the raw gyro, accelerometer, magnetometer, and pressure data.

For a demonstration of what you can do with this data, you can turn an Arduino connected to a AltIMU-10 v5 into an attitude and heading reference system, or AHRS, with this Arduino program. It uses the data from the AltIMU-10 v5 to calculate estimated roll, pitch, and yaw angles, and you can visualize the output of the AHRS with a 3D test program on your PC (as shown in a screenshot above). This software is based on the work of Jordi Munoz, William Premerlani, Jose Julio, and Doug Weibel.

The datasheets provide all the information you need to use the sensors on the AltIMU-10 v5, but picking out the important details can take some time. Here are some pointers for communicating with and configuring the LSM6DS33, LIS3MDL, and LPS25H that we hope will get you up and running a little bit faster:

The gyro, accelerometer, magnetometer, and pressure sensor are all in power-down mode by default. You have to turn them on by setting the correct configuration registers.

You can read or write multiple registers in the LIS3MDL or LPS25H with a single I²C command by asserting the most significant bit of the register address to enable address auto-increment.

The register address in the LSM6DS33 automatically increments during a multiple byte access, allowing you to read or write multiple registers in a single I²C command. Unlike how some other ST sensors work, the auto-increment is enabled by default; you can turn it off with the IF_INC field in the CTRL3_C register.

In addition to the datasheets, ST provides application notes for the LSM6DS33 (1MB pdf) and LIS3MDL (598k pdf) containing additional information and hints about using them.

We carry several inertial measurement and orientation sensors. The table below compares their capabilities:

People often buy this product together with:

The Pololu MinIMU-9 v5 is an inertial measurement unit (IMU) that packs an LSM6DS33 3-axis gyro and 3-axis accelerometer and an LIS3MDL 3-axis magnetometer onto a tiny 0.8″ × 0.5″ board. An I²C interface accesses nine independent rotation, acceleration, and magnetic measurements that can be used to calculate the sensor’s absolute orientation. The MinIMU-9 v5 board includes a voltage regulator and a level-shifting circuit that allow operation from 2.5 to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

The Pololu MinIMU-9 v5 is a compact (0.8″ × 0.5″) board that combines ST’s LSM6DS33 3-axis gyroscope and 3-axis accelerometer and LIS3MDL 3-axis magnetometer to form an inertial measurement unit (IMU); we therefore recommend careful reading of the LSM6DS33 datasheet (1MB pdf) and LIS3MDL datasheet (2MB pdf) before using this product. These sensors are great ICs, but their small packages make them difficult for the typical student or hobbyist to use. They also operate at voltages below 3.6 V, which can make interfacing difficult for microcontrollers operating at 5 V. The MinIMU-9 v5 addresses these issues by incorporating additional electronics, including a voltage regulator and a level-shifting circuit, while keeping the overall size as compact as possible. The board ships fully populated with its SMD components, including the LSM6DS33 and LIS3MDL, as shown in the product picture.

Compared to the previous MinIMU-9 v3, the v5 version uses newer MEMS sensors that provide some increases in accuracy (lower noise and zero-rate offsets). The MinIMU-9 v5 is pin-compatible with the MinIMU-9 v3, but because it uses different sensor chips, software written for older IMU versions will need to be changed to work with the v5.

The MinIMU-9 v5 is also pin-compatible with the AltIMU-10 v5, which offers the same functionality augmented by a digital barometer that can be used to obtain pressure and altitude measurements. The AltIMU includes a second mounting hole and is 0.2″ longer than the MinIMU. Any code written for the MinIMU-9 v5 should also work with the AltIMU-10 v5.

Side-by-side comparison of the MinIMU-9 v5 with the AltIMU-10 v5.

The LSM6DS33 and LIS3MDL have many configurable options, including dynamically selectable sensitivities for the gyro, accelerometer, and magnetometer. Each sensor also has a choice of output data rates. The two ICs can be accessed through a shared I²C/TWI interface, allowing the sensors to be addressed individually via a single clock line and a single data line. Additionally, a slave address configuration pin allows users to change the sensors’ I²C addresses and have two MinIMUs connected on the same I²C bus. (For additional information, see the I²C Communication section below.)

The nine independent rotation, acceleration, and magnetic readings (sometimes called 9DOF) provide all the data needed to make an attitude and heading reference system (AHRS). With an appropriate algorithm, a microcontroller or computer can use the data to calculate the orientation of the MinIMU board. The gyro can be used to very accurately track rotation on a short timescale, while the accelerometer and compass can help compensate for gyro drift over time by providing an absolute frame of reference. The respective axes of the two chips are aligned on the board to facilitate these sensor fusion calculations. (For an example of such a system using an Arduino, see the picture below and the Sample Code section at the bottom of this page.)

Visualization of AHRS orientation calculated from MinIMU-9 readings.

The carrier board includes a low-dropout linear voltage regulator that provides the 3.3 V required by the LSM6DS33 and LIS3MDL, allowing the module to be powered from a single 2.5 V to 5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 5 V systems. The board’s 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

Specifications

Dimensions: 0.8″ × 0.5″ × 0.1″ (20 mm × 13 mm × 3 mm)

Weight without header pins: 0.7 g (0.02 oz)

Operating voltage: 2.5 V to 5.5 V

Supply current: 5 mA

Output format (I²C):

Gyro: one 16-bit reading per axis

Accelerometer: one 16-bit reading per axis

Magnetometer: one 16-bit reading per axis

Gyro: one 16-bit reading per axis

Accelerometer: one 16-bit reading per axis

Magnetometer: one 16-bit reading per axis

Sensitivity range:

Gyro: ±125, ±245, ±500, ±1000, or ±2000°/s

Accelerometer: ±2, ±4, ±8, or ±16 g

Magnetometer: ±4, ±8, ±12, or ±16 gauss

Gyro: ±125, ±245, ±500, ±1000, or ±2000°/s

Accelerometer: ±2, ±4, ±8, or ±16 g

Magnetometer: ±4, ±8, ±12, or ±16 gauss

Included Components

A 1×6 strip of 0.1″ header pins and a 1×5 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards or solder wires directly to the board itself for more compact installations. The board features two mounting holes that work with #2 or M2 screws (not included).

Connections

A minimum of four connections is necessary to use the MinIMU-9 v5: VIN, GND, SCL, and SDA. VIN should be connected to a 2.5 V to 5.5 V source, GND to 0 volts, and SCL and SDA should be connected to an I²C bus operating at the same logic level as VIN. (Alternatively, if you are using the board with a 3.3 V system, you can leave VIN disconnected and bypass the built-in regulator by connecting 3.3 V directly to VDD.)

Pololu MinIMU-9 v5 gyro, accelerometer, and compass pinout.

Two Pololu MinIMU-9 v5 modules in a breadboard.

Pinout

The CS, data ready, and interrupt pins of the LSM6DS33 and LIS3MDL are not accessible on the MinIMU-9 v5. In particular, the absence of the CS pin means that the optional SPI interface of these ICs is not available. If you want these features, consider using our LSM6DS33 carrier and LIS3MDL carrier boards.

Schematic Diagram

The above schematic shows the additional components the carrier board incorporates to make the LSM6DS33 and LIS3MDL easier to use, including the voltage regulator that allows the board to be powered from a single 2.5 V to 5.5 V supply and the level-shifter circuit that allows for I²C communication at the same logic voltage level as VIN. This schematic is also available as a downloadable pdf: MinIMU-9 v5 schematic (106k pdf).

I²C Communication

The LSM6DS33’s gyro and accelerometer and the LIS3MDL’s magnetometer can be queried and configured through the I²C bus. Each of the three sensors acts as a slave device on the same I²C bus (i.e. their clock and data lines are tied together to ease communication). Additionally, level shifters on the I²C clock (SCL) and data lines (SDA) enable I²C communication with microcontrollers operating at the same voltage as VIN (2.5 V to 5.5 V). A detailed explanation of the protocols used by each device can be found in the LSM6DS33 datasheet (1MB pdf) and the LIS3MDL datasheet (2MB pdf). More detailed information about I²C in general can be found in NXP’s I²C-bus specification (1MB pdf).

The LSM6DS33 and LIS3MDL each have separate slave addresses on the I²C bus. The board connects the slave address select pins (SA0 or SA1) of the two ICs together and pulls them both to VDD through a 10 kΩ resistor. You can drive the pin labeled SA0 low to change the slave address. This allows you to have two MinIMUs (or a MinIMU v5 and an AltIMU v5) connected on the same I²C bus. The following table shows the slave addresses of the sensors:

Both chips on the MinIMU-9 v5 are compliant with fast mode (400 kHz) I²C standards as well as with the normal mode.

We have written a basic LSM6DS33 Arduino library and LIS3MDL Arduino library that make it easy to interface the MinIMU-9 v5 with an Arduino or Arduino-compatible board like an A-Star. They also make it simple to configure the sensors and read the raw gyro, accelerometer, and magnetometer data.

For a demonstration of what you can do with this data, you can turn an Arduino connected to a MinIMU-9 v5 into an attitude and heading reference system, or AHRS, with this Arduino program. It uses the data from the MinIMU-9 to calculate estimated roll, pitch, and yaw angles, and you can visualize the output of the AHRS with a 3D test program on your PC (as shown in a screenshot above). This software is based on the work of Jordi Munoz, William Premerlani, Jose Julio, and Doug Weibel.

The datasheets provide all the information you need to use the sensors on the MinIMU-9 v5, but picking out the important details can take some time. Here are some pointers for communicating with and configuring the LSM6DS33 and LIS3MDL that we hope will get you up and running a little bit faster:

The gyro, accelerometer, and magnetometer are all in power-down mode by default. You have to turn them on by setting the correct configuration registers.

You can read or write multiple registers in the LIS3MDL with a single I²C command by asserting the most significant bit of the register address to enable address auto-increment.

The register address in the LSM6DS33 automatically increments during a multiple byte access, allowing you to read or write multiple registers in a single I²C command. Unlike how some other ST sensors work, the auto-increment is enabled by default; you can turn it off with the IF_INC field in the CTRL3_C register.

In addition to the datasheets, ST provides application notes for the LSM6DS33 (1MB pdf) and LIS3MDL (598k pdf) containing additional information and hints about using them.

We carry several inertial measurement and orientation sensors. The table below compares their capabilities:

People often buy this product together with:

This tiny logic level shifter features four bi-directional channels, allowing for safe and easy communication between devices operating at different logic levels. It can convert signals as low as 1.5 V to as high as 18 V and vice versa, and its four channels are enough to support most common bidirectional and unidirectional digital interfaces, including I²C, SPI, and asynchronous TTL serial.

As digital devices get smaller and faster, once ubiquitous 5 V logic has given way to ever lower-voltage standards like 3.3 V, 2.5 V, and even 1.8 V, leading to an ecosystem of components that need a little help talking to each other. For example, a 5 V part might fail to read a 3.3 V signal as high, and a 3.3 V part might be damaged by a 5 V signal. This level shifter solves these problems by offering bidirectional voltage translation of up to four independent signals, converting between logic levels as low as 1.5 V on the lower-voltage side and as high as 18 V on the higher-voltage side, and its compact size and breadboard-compatible pin spacing make it easy to integrate into projects.

The logic high levels on each side of the shifter are achieved by 10 kΩ pull-up resistors to their respective supplies; these provide quick enough rise times to allow decent conversion of fast mode (400 kHz) I²C signals or other similarly fast digital interfaces (e.g. SPI or asynchronous TTL serial). External pull-ups can be added to speed up the rise time further at the expense of higher current draw. See the schematic diagram below for more information.

Dual-supply bus translation:

Lower-voltage (LV) supply can be 1.5 V to 7 V

Higher-voltage (HV) supply can be LV to 18 V

Lower-voltage (LV) supply can be 1.5 V to 7 V

Higher-voltage (HV) supply can be LV to 18 V

Four bidirectional channels

Small size: 0.4″ × 0.5″ × 0.08″ (13 mm × 10 mm × 2 mm)

Breadboard-compatible pin spacing

Example wiring diagram for connecting 5 V and 3.3 V devices through the 4-channel bidirectional logic level shifter.

This logic level converter requires two supply voltages: the lower-voltage logic supply (1.5 V to 7 V) connects to the LV pin and the higher-voltage supply (LV to 18 V) connects to the HV pin. The HV supply must be higher than the LV supply for proper operation. Logic low voltages will pass directly from Hx to the corresponding Lx (and vice versa), while logic high voltages will be converted between the HV level to the LV level as the signal passes from Hx to Lx or Lx to Hx.

The level shifter circuit does not require a ground connection to either device, so there are no ground pins on the board. (Some competing level shifter modules provide ground connections that simply act as a pass-through; we have opted to leave these off and make the board smaller.) The two devices being connected through the level shifter must still share a common ground.

The picture below shows a level-shifted TTL serial connection (RX and TX) between a 5 V Arduino Uno and a 3.3 V Raspberry Pi.

Using the 4-channel bidirectional logic level shifter to create a serial connection between a 5 V Arduino Uno and a 3.3 V Raspberry Pi.

A 0.1″-pitch male header strip is included for use with this board. The strip can be broken into smaller pieces and soldered in so the board can be used with perfboards, breadboards, or 0.1″ female connectors. Alternatively, wires can be soldered directly to the board for more compact installations. The connections are labeled on the back side of the of the PCB, so you might find it more convenient to solder the pins in the way that allows the labeled side to be facing up.

Schematic diagram

The logic level conversion is accomplished with a simple circuit consisting of a single n-channel MOSFET and a pair of 10 kΩ pull-up resistors for each channel. When Lx is driven low, the MOSFET turns on and the zero passes through to Hx. When Hx is driven low, Lx is also driven low through the MOSFET’s body diode, at which point the MOSFET turns on. In all other cases, both Lx and Hx are pulled high to their respective logic supply voltages. External pull-ups can be added to speed up the rise time. This same circuit is detailed in NXP’s application note on I²C bus level-shifting techniques, and we have used it before on carrier boards for 3.3 V sensors with I²C interfaces – like the MinIMU-9 – to enable them to work directly with both 3.3 V and 5 V systems.

This schematic is also available as a downloadable PDF (135k pdf).

People often buy this product together with:

This sensor module has 8 IR LED/phototransistor pairs mounted on a 0.375" pitch, making it a great detector for a line-following robot. Pairs of LEDs are arranged in series to halve current consumption, and a MOSFET allows the LEDs to be turned off for additional sensing or power-savings options. Each sensor provides a separate digital I/O-measurable output.

Note: The QTR-8RC reflectance sensor array requires digital I/O lines to take readings. The similar QTR-8A reflectance sensor array is available with analog outputs, and the reflectance sensor is available individually as a QTR-1RC reflectance sensor or QTR-1A reflectance sensor.

Functional Description

The QTR-8RC reflectance sensor array is intended as a line sensor, but it can be used as a general-purpose proximity or reflectance sensor. The module is a convenient carrier for eight IR emitter and receiver (phototransistor) pairs evenly spaced at intervals of 0.375" (9.525 mm). To use a sensor, you must first charge the output node by applying a voltage to its OUT pin. You can then read the reflectance by withdrawing the externally supplied voltage and timing how long it takes the output voltage to decay due to the integrated phototransistor. Shorter decay time is an indication of greater reflection. This measurement approach has several advantages, especially when coupled with the ability of the QTR-8RC module to turn off LED power:

No analog-to-digital converter (ADC) is required

Improved sensitivity over voltage-divider analog output

Parallel reading of multiple sensors is possible with most microcontrollers

Parallel reading allows optimized use of LED power enable option

The outputs are all independent, but the LEDs are arranged in pairs to halve current consumption. The LEDs are controlled by a MOSFET with a gate normally pulled high, allowing the LEDs to be turned off by setting the MOSFET gate to a low voltage. Turning the LEDs off might be advantageous for limiting power consumption when the sensors are not in use or for varying the effective brightness of the LEDs through PWM control.

This sensor was designed to be used with the board parallel to the surface being sensed.

The LED current-limiting resistors for 5 V operation are arranged in two stages; this allows a simple bypass of one stage to enable operation at 3.3 V. The LED current is approximately 20–25 mA, making the total board consumption just under 100 mA. The schematic diagram of the module is shown below:

For a similar array with three sensors, consider our QTR-3RC reflectance sensor array. The sensors on the QTR-8RC are also available individually as the QTR-1RC reflectance sensor, and the QTR-L-1RC is an alternative designed to be used with the board perpendicular to the surface.

QTR sensor size comparison. Clockwise from top left: QTR-3RC, QTR-1RC, QTR-L-1RC, QTR-8RC.

Specifications

Dimensions: 2.95" x 0.5" x 0.125" (without header pins installed)

Operating voltage: 3.3-5.0 V

Supply current: 100 mA

Output format: 8 digital I/O-compatible signals that can be read as a timed high pulse

Optimal sensing distance: 0.125" (3 mm)

Maximum recommended sensing distance: 0.375" (9.5 mm)

Weight without header pins: 0.11 oz (3.09 g)

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

Interfacing the QTR-8RC Outputs to Digital I/O Lines

The QTR-8RC module has eight identical sensor outputs that, like the Parallax QTI, require a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as several dozen microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all 8 sensors. If lower-frequency sampling is sufficient, substantial power savings can be realized by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 100 mA to 10 mA.

Our Pololu AVR library provides functions that make it easy to use these sensors with our Orangutan robot controllers; please see the QTR Reflectance Sensors section of our library command reference for more information. We also have a Arduino library for these sensors.

Breaking the Module in Two

If you don’t need or cannot fit all eight sensors, you can break off two sensors and still use all 8 sensors as two separate modules, as shown below. The PCB can be scored from both sides along the perforation and then bent until it snaps apart. Each of the two resulting pieces will function as an independent line sensor.

Included Components

This module ships with a 25-pin 0.1" header strip and a 100 Ohm through-hole resistor as shown below.

You can break the header strip into smaller pieces and solder them onto your reflectance sensor array as desired, or you can solder wires directly to the unit or use a right-angle header strip for a more compact installation. The pins on the module are arranged so that they can all be accessed using either an 11×1 strip or an 8×2 strip.

The resistor is required to make the two-sensor array functional after the original eight-sensor array is broken into two pieces. This resistor is only needed once the board has been broken.

Solder the included resistor to the 2-sensor array piece as shown to make the separated piece functional.

How it works in detail

For more information about how this sensor works, see the “How it works in detail” section of the QTR-1RC product page.

People often buy this product together with:

The QTR-1RC reflectance sensor carries a single infrared LED and phototransistor pair in an inexpensive, tiny 0.5" x 0.3" module that can be mounted almost anywhere and is great for edge detection and line following. The output is designed to be measured by a digital I/O line. This sensor is sold in packs of two units.

Note: The QTR-1RC reflectance sensor requires a digital I/O line to take readings. The similar QTR-1A reflectance sensor is available with an analog output.

Functional description

The Pololu QTR-1RC reflectance sensor carries a single infrared (IR) LED and phototransistor pair. To use the sensor, you must first charge the output node by applying a voltage to the OUT pin. You can then read the reflectance by withdrawing the externally supplied voltage and timing how long it takes the output voltage to decay due to the integrated phototransistor. Shorter decay time is an indication of greater reflection. This measurement approach has several advantages, especially when multiple units are used:

No analog-to-digital converter (ADC) is required

Improved sensitivity over voltage-divider analog output

Parallel reading of multiple sensors is possible with most microcontrollers

The LED current-limiting resistor is set to deliver approximately 17 mA to the LED when VIN is 5 V. The current requirement can be met by some microcontroller I/O lines, allowing the sensor to be powered up and down through an I/O line to conserve power.

This sensor was designed to be used with the board parallel to the surface being sensed. Because of its small size, multiple units can easily be arranged to fit various applications such as line sensing and proximity/edge detection.

For a line sensor with eight of these units arranged in a row, please see the QTR-8RC reflectance sensor array; for a similar array of three slightly different sensor components, see the QTR-3RC. For a similar, smaller sensor with longer range, and intended for use with the board perpendicular to the surface, please see the QTR-L-1RC reflectance sensor.

QTR sensor size comparison. Clockwise from top left: QTR-3RC, QTR-1RC, QTR-L-1RC, QTR-8RC.

Specifications

Dimensions: 0.3" x 0.5" x 0.1" (without optional header pins installed)

Operating voltage: 5.0 V

Supply current: 17 mA

Output format: digital I/O-compatible signal that can be read as a timed high pulse

Optimal sensing distance: 0.125" (3 mm)

Maximum recommended sensing distance: 0.375" (9.5 mm)

Weight without header pins: 0.008 oz (0.2 g)

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

Interfacing the QTR-1RC output to a digital I/O line

Like the Parallax QTI, this sensor requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as several dozen microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling.

Our Pololu AVR library provides functions that make it easy to use these sensors with our Orangutan robot controllers; please see the QTR Reflectance Sensors section of our library command reference for more information. We also have a Arduino library for these sensors.

Included components

This module has a single mounting hole intended for a #2 screw (not included); if this mounting hole is not needed, this portion of the PCB can be ground off to make the unit even smaller. Each pack of two reflectance sensors includes sets of straight male header strips and right-angle male header strips, which allow you to mount them in the orientation of your choice (note: the header pins might ship as 1×6 strips that you can break into two 1×3 pieces). You can also solder wires, such as ribbon cable, directly to the pads for the most compact installation.

How it works in detail

With only four components (or five, if you count the coupled IR LED and phototransistor separately), the operation of this sensor is relatively basic. The emitter side is just an IR LED with an appropriate current-limiting resistor. The light from the emitter leaves the sensor, reflects off a nearby surface, and returns to the detector.

The detector side is a resistor-capacitor (RC) circuit, where the resistance comes from the phototransistor and is a measure of the incident infrared light, and the decay time is proportional to the resistance. The first step of the sensor-reading process—driving the sensor output high—discharges the integrated 10 nF capacitor and puts both sides at the same voltage (VIN). Alternatively, you can think of this as “charging the output node”, and it is functionally equivalent to charging a capacitor with one side connected to ground. Once you are no longer supplying an external voltage to the output pin, the capacitor can slowly charge through the phototransistor, with the rate of charging being a function of the phototransistor’s resistance (which is in turn a function of the incident IR). As the capacitor charges, the voltage on the output side drops, eventually reaching zero when the capacitor is fully charged. Alternatively, you can think of this as “discharging the output node”, and it is functionally equivalent to discharging a capacitor with one side connected to ground.

The 220 Ω resistor on the OUT line serves to limit the current flow, making it possible for a microcontroller output to safely charge the output node prior to each reading. It has very little effect on the sensor output.

QTR-1RC and QTR-L-1RC reflectance sensor schematic diagram.

QTR-1RC output (yellow) when 1/8" above a white/black interface and microcontroller timing of that output (blue).

People often buy this product together with:

This small, inexpensive motor controller allows variable speed and direction control of two small, brushed DC motors using a simple serial interface, making it easy to add motors to your microcontroller- or computer-based project. The motor supply voltage range is 4.5 to 13.5 V; the continuous current per channel is up to 1 A (3 A peak). The logic supply can be as low as 2.7 V, allowing operation with modern microcontrollers running at 3.3 V.

The qik 2s9v1 is Pololu’s second-generation dual serial motor controller. The compact module allows any microcontroller or computer with a serial port (external RS-232 level converter required) or USB-to-serial adapter to easily drive two small, brushed DC motors with full direction and speed control. It provides ultrasonic, 8-bit PWM speed control via an advanced, two-way serial protocol that features automatic baud rate detection up to 38.4 kbps and optional CRC error checking. Two status LEDs give visual feedback about the serial connection and any encountered error conditions, making debugging easy, and a demo mode allows easy verification of proper operation.

The improvements over the previous generation and competing products include:

high-frequency (ultrasonic) PWM to eliminate switching-induced motor shaft hum or whine

a robust, high-speed communication protocol with user-configurable error condition response

visible LEDs and a demo mode to help troubleshoot problematic installations

reverse power protection on the motor supply (not on the logic supply)

For a more advanced, higher-power version of this controller, please consider the qik 2s12v10. For a simpler carrier of the qik’s motor driver, please consider the TB6612FNG dual motor driver carrier, and for a robot controller based on the qik’s driver, please consider the Baby Orangutan and Orangutan SV-328 robot controllers and 3pi robot, which connect the TB6612 to a user-programmable AVR microcontroller.

November 27, 2013 update: We have changed this product by replacing the large, silver electrolytic capacitor with a much smaller ceramic capacitor. This lowers the profile of the board but does not affect functionality at all. The main product picture shows this new version; the rest of the pictures on this product page still show the previous version with the tall electrolytic capacitor.

Simple bidirectional control of two DC brush motors.

4.5 V to 13.5 V motor supply range.

1 A maximum continuous current per motor (3 A peak).

2.7 V to 5.5 V logic supply range.

Logic-level, non-inverted, two-way serial control for easy connection to microcontrollers or robot controllers.

Optional automatic baud rate detection.

Two on-board indicator LEDs (status/heartbeat and serial error indicator) for debugging and feedback.

Serial error output to make it easier for the main controller to recover from a serial error condition.

Jumper-enabled demo mode allows initial testing without any programming.

Optional CRC error detection eliminates serial errors caused by noise or software faults.

Optional motor shutdown on serial error or timeout for additional safety.

Supports daisy-chaining the qik to other qiks and Pololu serial motor and servo controllers, allowing the control of up to hundreds of motors and servos with a single serial line.

Comprehensive user’s guide.

The qik ships with a 16×1 straight 0.100" male header strip, a 12×1 right angle 0.100" male header strip, and two red shorting blocks. This hardware offers several options when it comes to making connections to the qik.

For the most compact installation, wires can be directly soldered to the qik pins themselves. For less permanent connections, the 16×1 straight header strip can be broken into a 12×1 piece and two 2×1 pieces. The 2×1 pieces can optionally be soldered into the jumper pins, and the 12×1 header strip of your choice can be soldered into the qik control pins. This allows connections to the qik via custom-made cables that have female headers on them, or the qik can simply be plugged into a breadboard. Using the right angle header allows for a compact profile or for vertical mounting into a breadboard; using the straight header allows for breadboarding as shown in the picture above.

We have written a basic Arduino library for the qik dual serial motor controllers that makes it simple to interface these controllers with an Arduino. The library handles the details of serial communication with the qik, allowing two brushed DC motors to be controlled easily.

People often buy this product together with:

This compact board breaks out the pins of a microSD card connector necessary to interface with the card through SPI (Serial Peripheral Interface), and it can be directly integrated into 5 V systems thanks to its on board 3.3 V regulator and level shifting circuits. The 0.1″ pin spacing allows compatibility with standard perfboards, solderless breadboards, and 0.1" connectors.

This carrier board makes it easy to interface a microSD memory card (originally known as TransFlash) with an SPI-capable microcontroller, offering a convenient and inexpensive way to add gigabytes of non-volatile storage to an embedded project. It includes a 3.3 V regulator and level shifters on the four SPI lines, enabling direct integration into 5 V systems, and it provides access to the all of the connections through single 1×9 row of 0.1″-spaced through-holes. A breakaway 0.1″ male header strip is included, which can be soldered in to use the board with breadboards, perfboards, or 0.1″ female connectors, and the board has two mounting holes for #2 or M2 screws.

Breakout Board for microSD Card with 3.3V Regulator and Level Shifters with included header pins.

Breakout Board for microSD Card with 3.3V Regulator and Level Shifters plugged into a breadboard with microSD card (not included) inserted.

For 3.3 V projects, we carry a smaller Breakout Board for MicroSD Card without the 3.3 V regulator, level shifters, and mounting holes. This more basic module (shown in the right picture below) breaks out all of the microSD pins (including the ones used for the SD bus mode interface) rather than just the SPI-interface pins.

Breakout Board for microSD Card with 3.3V Regulator and Level Shifters.

Breakout Board for microSD Card.

For a microSD socket and user-programmable microcontroller on a single board, consider our A-Star 32U4 Prime controllers, which essentially use the same level-shifting circuits to interface a microSD card with an Arduino-compatible ATmega32U4 MCU running at 5 V.

Since many microcontrollers have built-in SPI interfaces, most hobbyist projects communicate with Secure Digital cards in SPI bus mode; this is the only mode supported by this board. (The alternative SD bus mode is proprietary, and a license from the SD Association is required for access to the full specifications.) The pins on this board are labeled according to their functions in SPI mode.

The board is powered by applying 5 V to the VDD pin, and all of the logic pins can be interfaced directly with 5 V systems thanks to integrated level shifters. The output of the integrated 3.3 V regulator can be accessed through the 3V3 pin, and the regulator can be disabled to turn off the microSD card and save power by driving the EN pin low.

By default, the EN and CD (Card Detect) pins are each pulled up to VDD through 100 kΩ resistors. However, there are cuttable traces on the underside of the board to allow you to disconnect each pull-up as desired. These traces are located between pairs of pads (labeled “EN” and “CD” on the board’s silkscreen) that can be bridged with solder to reconnect the pull-up resistor. Alternatively, the neighboring EN and CD pads of these surface-mount jumpers (highlighted in the picture below) can be connected if you want the regulator to automatically be enabled when the microSD card is inserted and disabled when it is removed.

Communicating with a microSD card

The SD Association publishes a set of simplified specifications for SD cards containing information on interfacing with them. However, there are a number of ways to get started without understanding the specifications or writing your own code from scratch, since many microcontroller development platforms provide libraries for communicating with SD cards. For example:

The SD library for Arduino provides functions for accessing files and directories on an SD card. (It also works with Arduino-compatible boards like our A-Star programmable controllers.)

The SD Card File System library for mbed allows similar filesystem access.

Schematic

Breakout Board for Micro SD Card with 3.3V Regulator and Level Shifter schematic diagram.

This schematic is also available as a downloadable pdf (106k pdf).

People often buy this product together with:

Add quadrature encoders to your LP, MP, or HP micro metal gearmotors (extended back shaft version required) with this kit that uses a magnetic disc and hall effect sensors to provide 12 counts per revolution of the motor shaft. The sensors operate from 2.7 V to 18 V and provide digital outputs that can be connected directly to a microcontroller or other digital circuit.Note: This version is not compatible with the HPCB micro metal gearmotors; it is only compatible with LP, MP, and HP dual-shaft micro metal gearmotors.

Discontinuation notice: This encoder is not compatible with our HPCB micro metal gearmotors (the HPCB motor terminals are too large to fit the corresponding PCB holes), but it is compatible with the LP, MP, and HP versions of our micro metal gearmotors. We have released a new version of this board that enlarges the motor terminal holes so they are compatible with all our micro metal gearmotors. The new version is functionally identical to this older version and can serve as a drop-in replacement. We will be discontinuing this product when the remaining stock is gone.

These older encoders are now only available by large-volume special order. Please contact us for more information.

Magnetic Encoder Kit for Micro Metal Gearmotors (old version; not compatible with HPCB micro metal gearmotors).

Magnetic Encoder Kit for Micro Metal Gearmotors (HPCB compatible).

This kit includes two dual-channel Hall Effect sensor boards and two 6-pole magnetic discs that can be used to add quadrature encoding to two micro metal gearmotors with extended back shafts (motors are not included with this kit). The encoder board senses the rotation of the magnetic disc and provides a resolution of 12 counts per revolution of the motor shaft when counting both edges of both channels. To compute the counts per revolution of the gearbox output shaft, multiply the gear ratio by 12.

This compact encoder solution fits within the 12 mm × 10 mm cross section of the motors on three of the four sides, and it only extends 0.6 mm past the edge of the fourth side (note: if you need it to be flush with that last side, you can carefully grind the board down a little and solder to the remaining half-holes). The assembly does not extend past the end of the extended motor shaft, which protrudes 5 mm beyond the plastic end cap on the back of the motor.

Note: This sensor system is intended for users comfortable with the physical encoder installation. It only works with micro metal gearmotors that have extended back shafts.

The encoder board is designed to be soldered directly to the back of the motor, with the back shaft of the motor protruding through the hole in the middle of the circuit board. One way to achieve good alignment between the board and the motor is to tack down the board to one motor pin and to solder the other pin only when the board is flat and well aligned. Be careful to avoid prolonged heating of the motor pins, which could deform the plastic end cap of the motor or the motor brushes. Once the board is soldered down to the two terminals, the motor leads are connected to the M1 and M2 pads along the edge of the board; the remaining four pads are used to power the sensors and access the two quadrature outputs:

The sensors are powered through the VCC and GND pins. VCC can be 2.7 V to 18 V, and the quadrature outputs A and B are digital signals that are either driven low (0 V) by the sensors or pulled to VCC through 10 kΩ pull-up resistors, depending on the applied magnetic field. The sensors’ comparators have built-in hysteresis, which prevents spurious signals in cases where the motor stops near a transition point.

Encoder A and B outputs of a magnetic encoder on a high-power (HP) micro metal gearmotor running at 6 V.

The board’s six pads have a 2 mm pitch, so they do not work with common 0.1″ connectors. One option for connecting to the board is to solder in individual wires, such as in the example below:

Alternatively, you can solder a 2mm-pitch connector to the board. The examples below show a male header, which gives you the option of making a detachable cable terminated by a 6-pin 2mm-pitch female header. If the pins are angled over the motor, as shown in the picture below, they will just barely protrude through the holes in the board. Note that in this orientation, there is room to plug in a female header even when our extended micro metal gearmotor bracket is being used.

If the pins are pointed away from the motor, they will need to be angled so that they sufficiently clear the magnetic disc. With a decent soldering iron, it is possible to solder them in this orientation even after the encoder has been installed on the motor.

Once the board is soldered to the motor, the magnetic encoder disc can be pushed onto the motor shaft. One easy way to accomplish this is to press the motor onto the disc while it is sitting on a flat surface, pushing until the shaft makes contact with that surface. The size of the gap between the encoder disc and the sensor board does not have a big impact on performance as long as the motor shaft is at least all the way through the disc.

This schematic is also available as a downloadable pdf (125k pdf).

People often buy this product together with:

The six-channel Micro Maestro raises the performance bar for serial servo controllers with features such as a native USB interface and internal scripting control. Whether you want high-performance servo control (0.25μs resolution with built-in speed and acceleration control) or a general I/O controller (e.g. to interface with a sensor or ESC via your USB port), this tiny, versatile device will deliver. The fully assembled version ships with header pins installed.

For a full list of products shown in this video, see the blog post.

The Micro Maestro is the smallest of Pololu’s second-generation USB servo controllers. The Maestros are available in four sizes and can be purchased fully assembled or as partial kits:

Maestro family of USB servo controllers: Mini 24, Mini 18, Mini 12, and Micro 6.

Micro Maestro — fully assembled

Micro Maestro — partial kit

Mini Maestro 12 — fully assembled

Mini Maestro 12 — partial kit

Mini Maestro 18 — fully assembled

Mini Maestro 18 — partial kit

Mini Maestro 24 — fully assembled

Mini Maestro 24 — partial kit

The Mini Maestros offer higher channel counts and some additional features (see the Maestro comparison table below for details).

Micro Maestro 6-channel USB servo controller bottom view with quarter for size reference.

The Micro Maestro is a highly versatile servo controller and general-purpose I/O board in a highly compact (0.85"×1.20") package. It supports three control methods: USB for direct connection to a computer, TTL serial for use with embedded systems, and internal scripting for self-contained, host controller-free applications. The channels can be configured as servo outputs for use with radio control (RC) servos or electronic speed controls (ESCs), as digital outputs, or as analog inputs. The extremely precise, high-resolution servo pulses have a jitter of less than 200 ns, making these servo controllers well suited for high-performance applications such as robotics and animatronics, and built-in speed and acceleration control for each channel make it easy to achieve smooth, seamless movements without requiring the control source to constantly compute and stream intermediate position updates to the Micro Maestro. Units can be daisy-chained with additional Pololu servo and motor controllers on a single serial line.

A free configuration and control program is available for Windows and Linux, making it simple to configure and test the device over USB, create sequences of servo movements for animatronics or walking robots, and write, step through, and run scripts stored in the servo controller. The Micro Maestro’s 1 KB of internal script memory allows storage of servo positions that can be automatically played back without any computer or external microcontroller connected.

Because the Micro Maestro’s channels can also be used as general-purpose digital outputs and analog inputs, they provide an easy way to read sensors and control peripherals directly from a PC over USB, and these channels can be used with the scripting system to enable creation of self-contained animatronic displays that respond to external stimuli and trigger additional events beyond just moving servos.

Bottom view with dimensions (in inches) of Pololu Micro and Mini Maestro servo controllers.

The Micro Maestro is available fully assembled with 0.1″ male header pins installed as shown in the product picture or as a partial kit, which ship with these header pins included but unsoldered, allowing the use of different gender connectors or wires to be soldered directly to the pads for lighter, more compact installations. The Mini Maestro 12, 18, and 24 are also available fully assembled or as partial kits. A USB A to mini-B cable (not included) is required to connect this device to a computer. The Micro and Mini Maestros have 0.086″ diameter mounting holes that work with #2 and M2 screws.

Micro Maestro 6-channel USB servo controller assembled.

Micro Maestro 6-channel USB servo controller partial kit.

Three control methods: USB, TTL (5V) serial, and internal scripting

0.25μs output pulse width resolution (corresponds to approximately 0.025° for a typical servo, which is beyond what the servo could resolve)

Pulse rate configurable from 33 to 100 Hz (2)

Wide pulse range of 64 to 3280 μs (2)

Individual speed and acceleration control for each channel

Channels can be optionally configured to go to a specified position or turn off on startup or error

Channels can also be used as general-purpose digital outputs or analog inputs

A simple scripting language lets you program the controller to perform complex actions even after its USB and serial connections are removed

Comprehensive user’s guide

Free configuration and control application for Windows makes it easy to:

Configure and test your controller

Create, run, and save sequences of servo movements for animatronics and walking robots

Write, step through, and run scripts stored in the servo controller

Configure and test your controller

Create, run, and save sequences of servo movements for animatronics and walking robots

Write, step through, and run scripts stored in the servo controller

Two ways to write software to control the Maestro from a PC:

Virtual COM port makes it easy to send serial commands from any development environment that supports serial communication

Pololu USB Software Development Kit allows use of more advanced native USB commands and includes example code in C#, Visual Basic .NET, and Visual C++

Virtual COM port makes it easy to send serial commands from any development environment that supports serial communication

Pololu USB Software Development Kit allows use of more advanced native USB commands and includes example code in C#, Visual Basic .NET, and Visual C++

TTL serial features:

Supports 300 – 200000 bps in fixed-baud mode, 300 – 115200 bps in autodetect-baud mode (2)

Simultaneously supports the Pololu protocol, which gives access to advanced functionality, and the simpler Scott Edwards MiniSSC II protocol (there is no need to configure the device for a particular protocol mode)

Can be daisy-chained with other Pololu servo and motor controllers using a single serial transmit line

Can function as a general-purpose USB-to-TTL serial adapter for projects controlled from a PC

Supports 300 – 200000 bps in fixed-baud mode, 300 – 115200 bps in autodetect-baud mode (2)

Simultaneously supports the Pololu protocol, which gives access to advanced functionality, and the simpler Scott Edwards MiniSSC II protocol (there is no need to configure the device for a particular protocol mode)

Can be daisy-chained with other Pololu servo and motor controllers using a single serial transmit line

Can function as a general-purpose USB-to-TTL serial adapter for projects controlled from a PC

Our Maestro Arduino library makes it easier to get started controlling a Maestro from an Arduino or compatible boards like our A-Stars

Board can be powered off of USB or a 5 – 16 V battery, and it makes the regulated 5V available to the user

Compact size of 0.85" × 1.20" (2.16 × 3.05 cm) and light weight of 0.17 oz (4.8 g) with headers

Upgradable firmware

1 This is the weight of the board without header pins or terminal blocks.

2 The available pulse rate and range depend on each other and factors such as baud rate and number of channels used. See the Maestro User’s Guide for details.

3 The user script system is more powerful on the Mini Maestro than on the Micro Maestro. See See the Maestro User’s Guide for details.

The Micro and Mini Maestros are available with through-hole connectors preinstalled or as partial kits, with the through-hole connectors included but not soldered in. The preassembled versions are appropriate for those who want to be able to use the product without having to solder anything or who are happy with the default connector configuration, while the partial kit versions enable the installation of custom connectors, such as right-angle headers that allow servos to be plugged in from the side rather than the top, or colored header pins that make it easier to tell which way to plug in the servo cables. The following picture shows an example of a partial-kit version of the 24-channel Mini Maestro assembled with colored male header pins:

24-channel Mini Maestro (partial kit version) assembled with colored male header pins.

Micro Maestro as the brains of a tiny hexapod robot.

Serial servo controller for multi-servo projects (e.g. robot arms, animatronics) based on BASIC Stamp or Arduino platforms.

PC-based servo control over USB port

PC-based control of motors by interfacing with an ESC over USB

PC interface for sensors and other electronics:

Read a gyro or accelerometer from a PC for novel user interfaces

Read a gyro or accelerometer from a PC for novel user interfaces

General I/O expansion for microcontroller projects

Programmable, self-contained Halloween or Christmas display controller that responds to sensors. The picture to the right and the video below show a self-contained hexapod robot that uses three micro servos and two digital distance sensors for autonomous walking.

Self-contained servo tester

An example setup using a Micro Maestro to control a ShiftBar and Satellite LED Module is shown in the picture below and one of the videos above. Maestro source code to control a ShiftBar or ShiftBrite is available in the Example scripts section of the Maestro User’s guide.

Connecting the Micro Maestro to a chain of ShiftBars. A single 12V supply powers all of the devices.

People often buy this product together with:

This sensor is a carrier/breakout board for ST’s VL53L0X laser-ranging sensor, which measures the range to a target object up to 2 m away. The VL53L0X uses time-of-flight measurements of infrared pulses for ranging, allowing it to give accurate results independent of the target’s color and surface. Distance measurements can be read through a digital I²C interface. The board has a 2.8 V linear regulator and integrated level-shifters that allow it to work over an input voltage range of 2.6 V to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

The VL53L0X from ST Microelectronics is a time-of-flight ranging system integrated into a compact module. This board is a carrier for the VL53L0X, so we recommend careful reading of the VL53L0X datasheet (1MB pdf) before using this product.

The VL53L0 uses ST’s FlightSense technology to precisely measure how long it takes for emitted pulses of infrared laser light to reach the nearest object and be reflected back to a detector, so it can be considered a tiny, self-contained lidar system. This time-of-flight (TOF) measurement enables it to accurately determine the absolute distance to a target without the object’s reflectance greatly influencing the measurement. The sensor can report distances of up to 2 m (6.6 ft) with 1 mm resolution, but its effective range and accuracy (noise) depend heavily on ambient conditions and target characteristics like reflectance and size, as well as the sensor configuration. (The sensor’s accuracy is specified to range from ±3% at best to over ±10% in less optimal conditions.)

Ranging measurements are available through the sensor’s I²C (TWI) interface, which is also used to configure sensor settings, and the sensor provides two additional pins: a shutdown input and an interrupt output.

The VL53L0X is a great IC, but its small, leadless, LGA package makes it difficult for the typical student or hobbyist to use. It also operates at a recommended voltage of 2.8 V, which can make interfacing difficult for microcontrollers operating at 3.3 V or 5 V. Our breakout board addresses these issues, making it easier to get started using the sensor, while keeping the overall size as small as possible.

The carrier board includes a low-dropout linear voltage regulator that provides the 2.8 V required by the VL53L0X, which allows the sensor to be powered from a 2.6 V to 5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 3.3 V or 5 V systems, and the board’s 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards. The board ships fully populated with its SMD components, including the VL53L0X, as shown in the product picture.

For for similar alternatives to this sensor, see our shorter-range 60 cm VL6180X carrier and longer-range 400 cm VL53L1X carrier. Both of these are physical drop-in replacements for the VL53L0X carrier, but they have different APIs, so software for the VL53L0X will need to be rewritten to work with the VL6180X or VL53L1X.

VL53L0X datasheet graph of typical ranging performance (in default mode).

Specifications

Dimensions: 0.5″ × 0.7″ × 0.085″ (13 mm × 18 mm × 2 mm)

Weight without header pins: 0.5 g (0.02 oz)

Operating voltage: 2.6 V to 5.5 V

Supply current: 10 mA (typical average during active ranging)

Varies with configuration, target, and environment. Peak current can reach 40 mA.

Varies with configuration, target, and environment. Peak current can reach 40 mA.

Output format (I²C): 16-bit distance reading (in millimeters)

Distance measuring range: up to 2 m (6.6 ft); see the graph at the right for typical ranging performance.

Effective range depends on configuration, target, and environment.

The datasheet does not specify a minimum range, but in our experience, the effective limit is about 3 cm.

Effective range depends on configuration, target, and environment.

The datasheet does not specify a minimum range, but in our experience, the effective limit is about 3 cm.

Included components

A 1×7 strip of 0.1″ header pins and a 1×7 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards, or you can solder wires directly to the board itself for more compact installations.

VL53L0X Time-of-Flight Distance Sensor Carrier with included header pins.

VL53L0X Time-of-Flight Distance Sensor Carrier in a breadboard.

The board has two mounting holes spaced 0.5″ apart that work with #2 and M2 screws (not included).

Important note: This product might ship with a protective liner covering the sensor IC. The liner must be removed for proper sensing performance.

Connections

At least four connections are necessary to use the VL53L0X board: VIN, GND, SCL, and SDA. The VIN pin should be connected to a 2.6 V to 5.5 V source, and GND should be connected to 0 volts. An on-board linear voltage regulator converts VIN to a 2.8 V supply for the VL53L0X IC.

The I²C pins, SCL and SDA, are connected to built-in level-shifters that make them safe to use at voltages over 2.8 V; they should be connected to an I²C bus operating at the same logic level as VIN.

The XSHUT pin is an input and the GPIO1 pin is an open-drain output; both pins are pulled up to 2.8 V by the board. They are not connected to level-shifters on the board and are not 5V-tolerant, but they are usable as-is with many 3.3 V and 5 V microcontrollers: the microcontroller can read the GPIO1 output as long as its logic high threshold is below 2.8 V, and the microcontroller can alternate its own output between low and high-impedance states to drive the XSHUT pin. Alternatively, our 4-channel bidirectional logic level shifter can be used externally with those pins.

Pinout

Schematic diagram

The above schematic shows the additional components the carrier board incorporates to make the VL53L0 easier to use, including the voltage regulator that allows the board to be powered from a 2.6 V to 5.5 V supply and the level-shifter circuit that allows for I²C communication at the same logic voltage level as VIN. This schematic is also available as a downloadable PDF (110k pdf).

I²C communication

The VL53L0X can be configured and its distance readings can be queried through the I²C bus. Level shifters on the I²C clock (SCL) and data (SDA) lines enable I²C communication with microcontrollers operating at the same voltage as VIN (2.6 V to 5.5 V). A detailed explanation of the I²C interface on the VL53L0X can be found in its datasheet (1MB pdf), and more detailed information about I²C in general can be found in NXP’s I²C-bus specification (1MB pdf).

The sensor’s 7-bit slave address defaults to 0101001b on power-up. It can be changed to any other value by writing one of the device configuration registers, but the new address only applies until the sensor is reset or powered off. ST provides an application note (196k pdf) that describes how to use multiple VL53L0X sensors on the same I²C bus by individually bringing each sensor out of reset and assigning it a unique address.

The I²C interface on the VL53L0X is compliant with the I²C fast mode (400 kHz) standard. In our tests of the board, we were able to communicate with the chip at clock frequencies up to 400 kHz; higher frequencies might work but were not tested.

Sensor configuration and control

In contrast with the information available for many other devices, ST has not publicly released a register map and descriptions or other documentation about configuring and controlling the VL53L0X. Instead, communication with the sensor is intended to be done through ST’s VL53L0X API (STSW-IMG005), a set of C functions that take care of the low-level interfacing. To use the VL53L0X, you can customize the API to run on a host platform of your choice using the information in the API documentation. Alternatively, it is possible to use the API source code as a guide for your own implementation.

Sample Code

We have written a basic Arduino library for the VL53L0X, which can be used as an alternative to ST’s official API for interfacing this sensor with an Arduino or Arduino-compatible controller. The library makes it simple to configure the VL53L0X and read the distance data through I²C. It also includes example sketches that show you how to use the library.

People often buy this product together with:

The Tic T500 USB Multi-Interface Stepper Motor Controller makes basic control of a stepper motor easy, with quick configuration over USB using our free software. The controller supports six control interfaces: USB, TTL serial, I²C, analog voltage (potentiometer), quadrature encoder, and hobby radio control (RC). This version incorporates an MPS MP6500 driver and ships with soldered header pins and terminal blocks. It can operate from 4.5 V to 35 V and can deliver up to approximately 1.5 A per phase without a heat sink or forced air flow (or 2.5 A max with sufficient additional cooling).

The Tic family of stepper motor controllers makes it easy to add basic control of a bipolar stepper motor to a variety of projects. These versatile, general-purpose modules support six different control interfaces: USB for direct connection to a computer, TTL serial and I²C for use with a microcontroller, RC hobby servo pulses for use in an RC system, analog voltages for use with a potentiometer or analog joystick, and quadrature encoder for use with a rotary encoder dial. They also offer many settings that can be configured using our free configuration utility (for Windows, Linux, and macOS). This software simplifies initial setup of the device and allows for in-system testing and monitoring of the controller via USB (a micro-B USB cable is required to connect the Tic to a computer).

The table below lists the members of the Tic family and shows the key differences among them.

1 See product pages and user’s guide for operating voltage limitations.

Tic T500 USB Multi-Interface Stepper Motor Controller, bottom view with dimensions.

Tic T834 USB Multi-Interface Stepper Motor Controller, bottom view with dimensions.

Tic T825 USB Multi-Interface Stepper Motor Controller, bottom view with dimensions.

Tic T249 USB Multi-Interface Stepper Motor Controller, bottom view with dimensions.

Features and specifications

Open-loop speed or position control of one bipolar stepper motor

A variety of control interfaces:

USB for direct connection to a computer

TTL serial operating at 5 V for use with a microcontroller

I²C for use with a microcontroller

RC hobby servo pulses for use in an RC system

Analog voltage for use with a potentiometer or analog joystick

Quadrature encoder input for use with a rotary encoder dial, allowing full rotation without limits (not for position feedback)

STEP/DIR inputs for compatibility with existing stepper motor control firmware

USB for direct connection to a computer

TTL serial operating at 5 V for use with a microcontroller

I²C for use with a microcontroller

RC hobby servo pulses for use in an RC system

Analog voltage for use with a potentiometer or analog joystick

Quadrature encoder input for use with a rotary encoder dial, allowing full rotation without limits (not for position feedback)

STEP/DIR inputs for compatibility with existing stepper motor control firmware

Acceleration and deceleration limiting

Maximum stepper speed: 50,000 steps per second

Very slow speeds down to 1 step every 200 seconds (or 1 step every 1428 seconds with reduced resolution).

Up to six different microstep resolutions:

The Tic T825, Tic T834, and T249 support full step, half step, 1/4 step, 1/8 step, 1/16 step, and 1/32 step

The Tic T500 supports full step, half step, 1/4 step, 1/8 step

The Tic T825, Tic T834, and T249 support full step, half step, 1/4 step, 1/8 step, 1/16 step, and 1/32 step

The Tic T500 supports full step, half step, 1/4 step, 1/8 step

Digitally adjustable current limit

Optional safety controls to avoid unexpectedly powering the motor

Input calibration (learning) and adjustable scaling degree for analog and RC signals

5 V regulator (no external logic voltage supply needed)

Optional limit switch inputs with homing capabilities

Optional kill switch inputs

STEP/DIR outputs for controlling external stepper motor drivers

Connects to a computer through USB via a USB A to Micro-B cable (not included)

Free configuration software available for Windows, Linux, and macOS

Comprehensive user’s guide

New revision (tic03b): As of 3 January 2019, we are shipping a new revision of the Tic T500 that works better with low-resistance, low-inductance stepper motors at high input voltages and high current limits, which could lead to lost steps with the original tic03a version. Please contact us if you have the older version and would like a free replacement.

The Tic T500 is based on the MP6500 IC from Monolithic Power Systems. This driver IC features automatic decay mode selection, using internal current sensing to automatically adjust the decay mode as necessary to provide the smoothest current waveform. The Tic T500 can operate from 4.5 V to 35 V and can deliver up to approximately 1.5 A continuous per phase without a heat sink or forced air flow (the peak current per phase is 2.5 A). This version is sold with connectors soldered so no soldering is necessary to use it.

Powering the Tic T500 with a supply voltage between 4.5 V and 5.5 V might cause its logic voltage to be lower than normal, which could affect operation. See the user’s guide for more information.

Tic T500 USB Multi-Interface Stepper Motor Controller (Connectors Soldered).

A version is also available with header pins and terminal blocks included but not soldered.

People often buy this product together with:

sensors

size(mm)

output

max current

optimalrange

LED

board

1

5.0 × 20.0

analog

3.5 mA

5 mA

10 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses.

Pinout diagram of the QTRX/QTRXL-HD-01A Reflectance Sensor Array.

QTRX-HD-01A Reflectance Sensor, front and back views.

QTRX/QTRXL-HD-01A Reflectance Sensor dimensions.

Dimensions: 5.0 × 20.0 × 4.4 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 1

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 5 mA

Output format: analog voltage (0 V to VCC)

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.25 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

4 mm × 9

37.0 × 20.0

analog

3.5 mA

22 mA

10 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage and separate controls for the odd and even emitters. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 40 mm. This version features high-performance, low-current QTRX sensors with lenses.

Pinout diagram of a QTRX-HD-xA Reflectance Sensor Array.

QTRX-HD-09A Reflectance Sensor Array, front and back views.

QTRX-HD-09A Reflectance Sensor Array, front and back views.

Dimensions: 37.0 × 20.0 × 3.0 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 9

Sensor pitch: 4 mm

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 22 mA

Output format: analog voltages (0 V to VCC)

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 40 mm

Weight: 2.1 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

8 mm × 5

37.0 × 20.0

RC (digital)

3.5 mA

14 mA

10 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 40 mm. This version features high-performance, low-current QTRX sensors with lenses.

Pinout diagram of a QTRX-MD-xRC Reflectance Sensor Array.

QTRX-MD-05RC Reflectance Sensor Array, front and back views.

QTRX-MD-05RC Reflectance Sensor Array dimensions.

Dimensions: 37.0 × 20.0 × 3.0 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 5

Sensor pitch: 8 mm

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 14 mA

Output format: digital I/O-compatible signals that can be read in parallel as timed high pulses

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 40 mm

Weight: 1.9 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

sensors

size(mm)

output

max current

optimalrange

LED

board

1

5.0 × 20.0

analog

30 mA

32 mA

5 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a traditional-style QTR sensor without lenses.

Pinout diagram of the QTR-HD-01A Reflectance Sensor Array.

QTR-HD-01A Reflectance Sensor, front and back views.

QTR-HD-01A Reflectance Sensor dimensions.

Dimensions: 5.0 × 20.0 × 3.9 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTR

Sensor count: 1

Full-brightness LED current: 30 mA (independent of supply voltage)

Max board current: 32 mA

Output format: analog voltage (0 V to VCC)

Optimal sensing distance: 5 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.25 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

People often buy this product together with:

sensors

size(mm)

output

max current

optimalrange

LED

board

1

5.0 × 20.0

RC (digital)

30 mA

32 mA

5 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a traditional-style QTR sensor without lenses.

Pinout diagram of the QTR-HD-01RC Reflectance Sensor Array.

QTR-HD-01RC Reflectance Sensor, front and back views.

QTR-HD-01RC Reflectance Sensor dimensions.

Dimensions: 5.0 × 20.0 × 3.9 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTR

Sensor count: 1

Full-brightness LED current: 30 mA (independent of supply voltage)

Max board current: 32 mA

Output format: digital I/O-compatible signal that can be read as a timed high pulse

Optimal sensing distance: 5 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.25 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

People often buy this product together with:

sensors

size(mm)

output

max current

optimalrange

LED

board

1

5.0 × 20.0

RC (digital)

3.5 mA

5 mA

10 mm

This IR LED/phototransistor pair is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features a high-performance, low-current QTRX sensor with lenses.

Pinout diagram of the QTRX/QTRXL-HD-01RC Reflectance Sensor Array.

QTRX-HD-01RC Reflectance Sensor, front and back views.

QTRX/QTRXL-HD-01RC Reflectance Sensor dimensions.

Dimensions: 5.0 × 20.0 × 4.4 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 1

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 5 mA

Output format: digital I/O-compatible signal that can be read as a timed high pulse

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.25 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

8 mm × 2

13.0 × 20.0

analog

3.5 mA

5 mA

10 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features high-performance, low-current QTRX sensors with lenses.

QTRX-MD-02A Reflectance Sensor Array dimensions.

Dimensions: 13.0 × 20.0 × 3.0 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 2

Sensor pitch: 8 mm

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 5 mA

Output format: analog voltages (0 V to VCC)

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.7 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

8 mm × 2

13.0 × 20.0

RC (digital)

3.5 mA

5 mA

10 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features high-performance, low-current QTRX sensors with lenses.

QTRX-MD-02RC Reflectance Sensor Array dimensions.

Dimensions: 13.0 × 20.0 × 3.0 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 2

Sensor pitch: 8 mm

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 5 mA

Output format: digital I/O-compatible signals that can be read in parallel as timed high pulses

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.7 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

4 mm × 3

13.0 × 20.0

analog

3.5 mA

9 mA

10 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features high-performance, low-current QTRX sensors with lenses.

QTRX-HD-03A Reflectance Sensor Array dimensions.

Dimensions: 13.0 × 20.0 × 3.0 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 3

Sensor pitch: 4 mm

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 9 mA

Output format: analog voltages (0 V to VCC)

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.8 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

4 mm × 3

13.0 × 20.0

RC (digital)

3.5 mA

9 mA

10 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features high-performance, low-current QTRX sensors with lenses.

QTRX-HD-03RC Reflectance Sensor Array dimensions.

Dimensions: 13.0 × 20.0 × 3.0 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTRX

Sensor count: 3

Sensor pitch: 4 mm

Full-brightness LED current: 3.5 mA (independent of supply voltage)

Max board current: 9 mA

Output format: digital I/O-compatible signals that can be read in parallel as timed high pulses

Optimal sensing distance: 10 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.8 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

4 mm × 3

13.0 × 20.0

analog

30 mA

62 mA

5 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features the traditional-style QTR sensors without lenses.

QTR-HD-03A Reflectance Sensor Array dimensions.

Dimensions: 13.0 × 20.0 × 2.5 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTR

Sensor count: 3

Sensor pitch: 4 mm

Full-brightness LED current: 30 mA (independent of supply voltage)

Max board current: 62 mA

Output format: analog voltages (0 V to VCC)

Optimal sensing distance: 5 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.8 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

pitch × sensors

size(mm)

output

max current

optimalrange

LED

board

4 mm × 3

13.0 × 20.0

RC (digital)

30 mA

62 mA

5 mm

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 30 mm. This version features the traditional-style QTR sensors without lenses.

QTR-HD-03RC Reflectance Sensor Array dimensions.

Dimensions: 13.0 × 20.0 × 2.5 mm (see the dimension diagram (1MB pdf) for more details)

Operating voltage: 2.9 V to 5.5 V

Sensor type: QTR

Sensor count: 3

Sensor pitch: 4 mm

Full-brightness LED current: 30 mA (independent of supply voltage)

Max board current: 62 mA

Output format: digital I/O-compatible signals that can be read in parallel as timed high pulses

Optimal sensing distance: 5 mm

Maximum recommended sensing distance: 30 mm

Weight: 0.8 g

These reflectance sensors feature a linear array of infrared emitter/phototransistor pair modules in a high-density (4 mm pitch) or medium-density (8 mm pitch) arrangement, which makes them well suited for applications that require detection of changes in reflectivity. This change in reflectivity can be due to a color change at a fixed distance, such as when sensing a black line on a white background, as well as due to a change in the distance to or presence of an object in front of the sensor. A variety of sensor counts and densities is available so you can pick the ideal arrangement for your application. Since the outputs are all independent, you can connect just some of the channels to attain an irregular or non-standard sensor spacing.

Unlike our original QTR sensor modules, these units have integrated LED drivers that provide brightness control independent of the supply voltage, which can be anywhere from 2.9 V to 5.5 V, while enabling optional dimming to any of 32 possible brightness settings. For high-density (HD) modules with five or more sensors and medium-density (MD) modules with eleven or more sensors, there are separate controls for the odd-numbered and even-numbered LEDs, which gives you extra options for detecting light reflected at various angles. See the “Emitter control” section below for more information on using this feature.

Two different sensor options are available, denoted by “QTR” or “QTRX” in the product name. The “QTR” versions feature lower-cost sensor modules without lenses while the “QTRX” versions feature higher-performance sensor modules with lenses, which allow similar performance at a much lower IR LED current. You can see the two different sensor styles in the pictures below of the 4-channel modules:

QTR-HD-04A Reflectance Sensor Array.

QTRX-HD-04RC Reflectance Sensor Array.

We also have several single-channel modules with the “QTRXL” designator that offer extra-long range by using the QTRX-style sensor module with higher current through the emitter.

Each sensor option is available in two output types: an “A” version with analog voltage outputs between 0 V and VCC, and an “RC” version with outputs that can be read with a digital I/O line on a microcontroller by first setting the lines high and then releasing them and timing how long it takes them to read as low (typically anywhere from a few microseconds to a few milliseconds). The lower the output voltage or shorter the voltage decay time, the higher the reflectance. The following simplified schematic diagrams show the circuits for the individual channels:

Schematic diagrams of individual QTR sensor channels for A version (left) and RC version (right). This applies only to the newer QTRs with dimmable emitters.

Our Arduino library makes it easy to use these sensor modules with an Arduino or compatible controller by providing methods for controlling the emitters, calibrating the module, and reading the individual sensor values from either the A or RC versions. It also has a method specifically for line-following applications to compute the location of the line under the array.

Note: Unlike most of our products, these sensor arrays do not ship with any headers or connectors included, so you will need to supply your own or solder wires directly to the board to use it. See our selection of male headers, female headers, and pre-crimped wires for various connector options.

Each sensor on the A versions outputs its reflectance measurement as an analog voltage that can range from 0 V when the reflectance is very strong to VCC when the reflectance is very weak. The typical sequence for reading a sensor is:

Use a microcontroller’s analog-to-digital converter (ADC) to measure the voltages.

Use a comparator with an adjustable threshold to convert each analog voltage into a digital (i.e. black/white) signal that can be read by the digital I/O line of a microcontroller.

Connect each output directly to a digital I/O line of a microcontroller and rely upon its logic threshold.

This last method will work if you are able to get high reflectance from your white surface as depicted in the left image, but will probably fail if you have a lower-reflectance signal profile like the one on the right.

QTR-1A output 1/8" away from a spinning white disk with a black line on it.

QTR-1A output 3/8" away from a spinning white disk with a black line on it.

Each sensor on the RC versions requires a digital I/O line capable of driving the output line high and then measuring the time for the output voltage to decay. The typical sequence for reading a sensor is:

QTR-1RC output (yellow) when 1/8" above a black line and microcontroller timing of that output (blue).

QTR-1RC output (yellow) when 1/8" above a white surface and microcontroller timing of that output (blue).

Turn on IR LEDs (optional).

Set the I/O line to an output and drive it high.

Allow at least 10 μs for the sensor output to rise.

Make the I/O line an input (high impedance).

Measure the time for the voltage to decay by waiting for the I/O line to go low.

Turn off IR LEDs (optional).

These steps can typically be executed in parallel on multiple I/O lines.

With a strong reflectance, the decay time can be as low as a few microseconds; with no reflectance, the decay time can be up to a few milliseconds. The exact time of the decay depends on your microcontroller’s I/O line characteristics. Meaningful results can be available within 1 ms in typical cases (i.e. when not trying to measure subtle differences in low-reflectance scenarios), allowing up to 1 kHz sampling of all sensors. If lower-frequency sampling is sufficient, you can achieve substantial power savings by turning off the LEDs. For example, if a 100 Hz sampling rate is acceptable, the LEDs can be off 90% of the time, lowering average current consumption from 125 mA to 13 mA.

These reflectance sensor arrays maintain a constant current through their IR emitters, keeping the emitters’ brightness constant, independent of the supply voltage (2.9 V to 5.5 V). The emitters can be controlled with the board’s CTRL pins, and the details of the control depends on the array size and density:

HD units with 5 or more sensors and MD units with 11 or more sensors have two emitter control pins: CTRL ODD and CTRL EVEN. By default, these are connected together with a 1 kΩ resistor and pulled up, turning on all the emitters by default and allowing them to be controlled with a signal on either pin, but the CTRL ODD and CTRL EVEN pins can be driven separately for independent control of the odd-numbered and even-numbered emitters.

MD units with 3-10 sensors also have two emitter control pins since these are made by only populating every other sensor on an HD board, but only the CTRL ODD pin will have an effect on these versions (it is not possible to independently control alternate emitters).

HD units with 4 or fewer sensors and MD units with 2 or fewer sensors have a single CTRL pin that controls all of the emitters.

Driving a CTRL pin low for at least 1 ms turns off the associated emitter LEDs, while driving it high (or allowing the board to pull it high) turns on the emitters with the board’s default (full) current, which is 30 mA for “QTR” versions and 3.5 mA for “QTRX” versions. For more advanced use, the CTRL pin can be pulsed low to cycle the associated emitters through 32 dimming levels.

Demo of IR LED dimming and independent even/odd control on the QTR-HD-07x (as seen through an old digital camera that can see IR).

Demo of IR LED dimming and independent even/odd control on the QTRX-HD-07x (as seen through an old digital camera that can see IR).

To send a pulse, you should drive the CTRL pin low for at least 0.5 μs (but no more than 300 μs), then high for at least 0.5 μs; (it should remain high after the last pulse). Each pulse causes the driver to advance to the next dimming level, wrapping around to 100% after the lowest-current level. Each dimming level corresponds to a 3.33% reduction in current, except for the last three levels, which represent a 1.67% reduction, as shown in the table below. Note that turning the LEDs off with a >1 ms pulse and then back on resets them to full current.

For example, to reduce the emitter current to 50%, you would apply 15 low pulses to the CTRL pin and then keep it high after the last pulse.

This gearmotor is a miniature high-power, 6 V brushed DC motor with long-life carbon brushes and a 248.98:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.

Key specifications:

voltage

no-load performance

stall extrapolation

6 V

130 RPM, 100 mA

3.2 kg⋅cm (44 oz⋅in), 1.5 A

These tiny brushed DC gearmotors are available in a wide range of gear ratios—from 5:1 up to 1000:1—and with five different motors: high-power 6 V and 12 V motors with long-life carbon brushes (HPCB), and high-power (HP), medium power (MP), and low power (LP) 6 V motors with shorter-life precious metal brushes. The 6 V and 12 V HPCB motors offer the same performance at their respective nominal voltages, just with the 12 V motor drawing half the current of the 6 V motor. The 6 V HPCB and 6 V HP motors are identical except for their brushes, which only affect the lifetime of the motor.

The HPCB versions (shown on the left in the picture below) can be differentiated from versions with precious metal brushes (shown on the right) by their copper-colored terminals. Note that the HPCB terminals are 0.5 mm wider than those on the other micro metal gearmotor versions (2 mm vs. 1.5 mm), and they are about 1 mm closer together (6 mm vs. 7 mm).

Versions of these gearmotors are also available with an additional 1 mm-diameter output shaft that protrudes from the rear of the motor. This 4.5 mm-long rear shaft rotates at the same speed as the input to the gearbox and offers a way to add an encoder, such as our magnetic encoder for micro metal gearmotors (see the picture on the right), to provide motor speed or position feedback.

With the exception of the 1000:1 gear ratio versions, all of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change.

Please see the micro metal gearmotor datasheet (2MB pdf) for more information, including detailed performance graphs for each micro metal gearmotor version. You can also use our dynamically sortable micro metal gearmotor comparison table for search for the gearmotor that offers the best blend of speed, torque, and current-draw for your particular application. A more basic comparison table is available below.

Note: Stalling or overloading gearmotors can greatly decrease their lifetimes and even result in immediate damage. The recommended upper limit for instantaneous torque is 35 oz-in (2.5 kg-cm) for the 1000:1 gearboxes and 25 oz-in (2 kg*cm) for all the other gear ratios; we strongly advise keeping applied loads well under this limit. Stalls can also result in rapid (potentially on the order of seconds) thermal damage to the motor windings and brushes, especially for the versions that use high-power (HP and HPCB) motors; a general recommendation for brushed DC motor operation is 25% or less of the stall current.

In general, these kinds of motors can run at voltages above and below their nominal voltages; lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.

Exact gear ratio: ``(25×34×37×35×38) / (12×10×10×14×10) ~~ bb(248.98:1)``

In terms of size, these gearmotors are very similar to Sanyo’s popular 12 mm NA4S DC gearmotors, and gearmotors with this form factor are occasionally referred to as N20 motors. The versions with carbon brushes (HPCB) have slightly different terminal and end-cap dimensions than the versions with precious metal brushes, but all of the other dimensions are identical.

Dimensions of versions with carbon brushes (HPCB)

Dimensions of the Pololu micro metal gearmotors with carbon brushes (HPCB). Units are mm over [inches].

Dimensions of versions with precious metal brushes (LP, MP, and HP)

Dimensions of the Pololu micro metal gearmotors with precious metal brushes: low-power (LP), medium-power (MP), and high-power (HP). Units are mm over [inches].

These diagrams are also available as a downloadable PDF (262k pdf).

Wheels and hubs: The micro metal gearmotor’s output shaft matches our assortment of Pololu wheels and the Solarbotics RW2i rubber wheel. You can also use our Pololu universal mounting hubs to mount custom wheels and mechanism to the micro metal gearmotor’s output shaft, and you can use our 12mm hex wheel adapter to use this motor with many common hobby RC wheels.

Pololu wheel 32×7mm on a micro metal gearmotor.

Black Pololu 70×8mm wheel on a Pololu micro metal gearmotor.

A pair of Pololu universal aluminum mounting hubs for 3 mm diameter shafts.

12mm Hex Wheel Adapter for 3mm Shaft on a Micro Metal Gearmotor.

Mounting brackets: Our mounting bracket (also available in white) and extended mounting bracket are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the Pololu wheel 42×19mm. Our micro metal gearmotors will also work with our 15.5D mm metal gearmotor bracket pair.

Black micro metal gearmotor mounting bracket pair with included screws and nuts.

White micro metal gearmotor mounting bracket pair with included screws and nuts.

Pololu micro metal gearmotor bracket extended with micro metal gearmotor.

Quadrature encoders: We offer several quadrature encoders that work with our micro metal gearmotors.

Magnetic Encoder on a Micro Metal Gearmotor with Extended Motor Shaft, assembled with ribbon cable wires.

Example of an installed micro metal gearmotor reflective optical encoder.

Note: The HPCB versions of our micro metal gearmotors are not compatible with our #2590 and #2591 optical encoders or our older #2598 magnetic encoders (the terminals are too wide to fit through the corresponding holes in the encoder boards). However, they are compatible with our newer #3081 magnetic encoders.

Motor controllers and drivers: We have a number of motor controllers, motor drivers, and robot controllers that make it easy to drive these micro metal gearmotors. For the 6 V micro metal gearmotors, consider the DRV8838 single-channel motor driver carrier, the DRV8833 dual motor driver carrier, and DRV8835 dual motor driver carrier (or DRV8835 shield for Arduino). For the 12 V micro metal gearmotors, consider the MAX14870 single-channel motor driver carrier, DRV8801 single-channel motor driver carrier, and A4990 dual motor driver carrier (or A4990 shield for Arduino).

DRV8838 Single Brushed DC Motor Driver Carrier.

Pololu A4990 Dual Motor Driver Shield for Arduino, bottom view.

DRV8835 dual motor driver carrier.

Current sensors: We have an assortment of Hall effect-based current sensors to choose from for those who need to monitor motor current:

ACS711EX current sensor carrier -15.5A to +15.5A.

ACS714 current sensor carrier -5A to +5A.

We also incorporate these motors into some of our products, including our Zumo robot and 3pi robot :

Assembled Zumo 32U4 robot.

Pololu 3pi robot.

We offer a wide selection of metal gearmotors that offer different combinations of speed and torque. Our metal gearmotor comparison table can help you find the motor that best meets your project’s requirements.

People often buy this product together with:

This sensor is a carrier/breakout board for ST’s VL6180X proximity and ambient light sensor, which measures the range to a target object up to 20 cm away (or 60 cm with reduced resolution). The VL6180X uses time-of-flight measurements of infrared pulses for ranging, allowing it to give accurate results independent of the target’s color and surface. Distance and ambient light level measurements can be read through a digital I²C interface. The board has a 2.8 V linear regulator and integrated level-shifters that allow it to work over an input voltage range of 2.7 V to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

The VL6180X from ST Microelectronics is a sensor that combines proximity ranging and ambient light level measurement capabilities into a single package. This board is a carrier for the VL6180X, so we recommend careful reading of the VL6180X datasheet (2MB pdf) before using this product.

Unlike simpler optical sensors that use the intensity of reflected light to detect objects, the VL6180 uses ST’s FlightSense technology to precisely measure how long it takes for emitted pulses of infrared laser light to reach the nearest object and be reflected back to a detector, making it essentially a short-range lidar sensor. This time-of-flight (TOF) measurement enables it to accurately determine the absolute distance to a target with 1 mm resolution, without the object’s reflectance influencing the measurement. The sensor is rated to perform ranging measurements of up to 10 cm (4″), but it can often provide readings up to 20 cm (8″) with its default settings. Furthermore, the VL6180X can be configured to measure ranges of up to 60 cm (24″) at the cost of reduced resolution, although successful ranging at these longer distances will depend heavily on the target and environment. (For more information, see “Range scaling factor” below.)

The VL6180 also includes an ambient light sensor, or ALS, that can measure the intensity of light with which it is illuminated. Ranging and ambient light measurements are available through the sensor’s I²C (TWI) interface, which is also used to configure sensor settings, and two independently-programmable GPIO pins can be configured as interrupt outputs.

The VL6180X is a great IC, but its small, leadless, LGA package makes it difficult for the typical student or hobbyist to use. It also operates at voltages below 3 V, which can make interfacing difficult for microcontrollers operating at 3.3 V or 5 V. Our breakout board addresses these issues, making it easier to get started using the sensor, while keeping the overall size as small as possible.

The carrier board includes a low-dropout linear voltage regulator that provides the 2.8 V required by the VL6180X, which allows the sensor to be powered from a 2.7 V to 5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 3.3 V or 5 V systems, and the board’s 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards. The board ships fully populated with its SMD components, including the VL6180X, as shown in the product picture.

For for similar, longer-range sensors, see our 200 cm VL53L0X carrier and 400 cm VL53L1X carrier. Both of these are physical drop-in replacements for the VL6180X carrier, but they have different APIs, so software for the VL6180X will need to be rewritten to work with the VL53L0X or VL53L1X.

VL6180X datasheet graph of typical ranging performance.

Specifications

Dimensions: 0.5″ × 0.7″ × 0.085″ (13 mm × 18 mm × 2 mm)

Weight without header pins: 0.5 g (0.02 oz)

Operating voltage: 2.7 V to 5.5 V

Supply current: 5 mA (typical; varies with configuration, target, and environment)

Output format (I²C): 8-bit distance reading (in millimeters), 16-bit ambient light reading

Distance measuring range: up to 10 cm (4″) specified; up to 60 cm (24″) possible with reduced resolution. See the graph at the right for typical ranging performance.

Ranging beyond 10 cm is possible with certain target reflectances and ambient conditions but not guaranteed by specifications. By default, the sensor can report distances up to 20 cm, or it can be configured to measure up to 60 cm with reduced resolution.

The datasheet does not specify a minimum range, but in our experience, the effective limit is about 1 cm.

Ranging beyond 10 cm is possible with certain target reflectances and ambient conditions but not guaranteed by specifications. By default, the sensor can report distances up to 20 cm, or it can be configured to measure up to 60 cm with reduced resolution.

The datasheet does not specify a minimum range, but in our experience, the effective limit is about 1 cm.

Included components

A 1×7 strip of 0.1″ header pins and a 1×7 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards, or you can solder wires directly to the board itself for more compact installations.

VL6180X Time-of-Flight Distance Sensor Carrier with included header pins.

VL6180X Time-of-Flight Distance Sensor Carrier in a breadboard.

The board has two mounting holes spaced 0.5″ apart that work with #2 and M2 screws (not included).

Connections

At least four connections are necessary to use the VL6180X board: VIN, GND, SCL, and SDA. The VIN pin should be connected to a 2.7 V to 5.5 V source, and GND should be connected to 0 volts. An on-board linear voltage regulator converts VIN to a 2.8 V supply for the VL6180X IC.

The I²C pins, SCL and SDA, are connected to built-in level-shifters that make them safe to use at voltages over 2.8 V; they should be connected to an I²C bus operating at the same logic level as VIN.

The two GPIO pins are open-drain outputs pulled up to 2.8 V by the board (although GPIO0 defaults to being a chip enable input). They are not connected to level-shifters on the board and are not 5V-tolerant, but they are usable as-is with many 3.3 V and 5 V microcontrollers: the microcontroller can read the sensor’s output as long as its logic high threshold is below 2.8 V, and the microcontroller can alternate its own output between low and high-impedance states to drive the pin. Alternatively, our 4-channel bidirectional logic level shifter can be used externally with those pins.

Pinout

Schematic diagram

The above schematic shows the additional components the carrier board incorporates to make the VL6180 easier to use, including the voltage regulator that allows the board to be powered from a 2.7 V to 5.5 V supply and the level-shifter circuit that allows for I²C communication at the same logic voltage level as VIN. This schematic is also available as a downloadable PDF (90k pdf).

I²C communication

The VL6180X can be configured and its distance and ambient light readings can be queried through the I²C bus. Level shifters on the I²C clock (SCL) and data (SDA) lines enable I²C communication with microcontrollers operating at the same voltage as VIN (2.7 V to 5.5 V). A detailed explanation of the I²C interface on the VL6180X can be found in its datasheet (2MB pdf), and more detailed information about I²C in general can be found in NXP’s I²C-bus specification (1MB pdf).

The sensor’s 7-bit slave address defaults to 0101001b on power-up. It can be changed to any other value by writing one of the device configuration registers, but the new address only applies until the sensor is reset or powered off.

The I²C interface on the VL6180X is compliant with the I²C fast mode (400 kHz) standard. In our tests of the board, we were able to communicate with the chip at clock frequencies up to 400 kHz; higher frequencies might work but were not tested.

Sample Code

We have written a basic Arduino library for the VL6180X that makes it easy to interface this sensor with an Arduino or Arduino-compatible controller. The library makes it simple to configure the VL6180X and read the distance and ambient light level data through I²C. It also includes example sketches that show you how to use the library.

Protocol hints

The datasheet provides a lot of information about this sensor, but a lot of essential info – including a mandatory initialization sequence – can only be found in other documents. Picking out the important details can take some time. Here are some pointers for communicating with and configuring the VL6180X that we hope will get you up and running a little bit faster:

Unlike many other I²C sensors from ST, which use 8-bit register addresses, the VL6180X uses 16-bit register addresses.

The sensor must be initialized with a particular sequence of settings on power-up or reset. This sequence is not covered in the datasheet, but it can be found in ST application note AN4545 (706k pdf) and design tip DT0037 (386k pdf). (Our Arduino library includes a function that performs this initialization.)

The two documents above can also help you understand basic procedures for configuring the VL6180X and getting readings from it. Additional documents, providing details on many other aspects of the VL6180X, can be found on ST’s product page for the VL6180X.

Both distance and ambient light measurements can be performed in either single-shot or continuous mode. In either mode, once each measurement is started, you must poll a status register to wait for it to complete. In continuous mode, you should ensure that the inter-measurement period you select is longer than the time it takes to actually perform each measurement.

Range scaling factor

Although the VL6180X specifications state a maximum “guaranteed” range of 10 cm, the sensor can report distances of up to 20 cm with its default settings. By configuring a range scaling factor, the potential maximum range of the sensor can be increased at the cost of lower resolution. Setting the scaling factor to 2 provides up to 40 cm range with 2 mm resolution, while a scaling factor of 3 provides up to 60 cm range with 3 mm resolution. In all cases, the reading is given as a number between 0 and 200; with the default 1× scaling, this corresponds directly to a distance in mm, but with 2× or 3× scaling, the raw reading will represent a measurement in units of 2 mm or 3 mm, respectively (so the reading should be multiplied by 2 or 3 to obtain a result in millimeters).

Range scaling is not mentioned in the VL6180X datasheet as of Rev 7, but it is available in the VL6180X API provided by ST (STSW-IMG003). Our Arduino library also provides functions to set the range scaling factor.

People often buy this product together with:

This sensor is a carrier/breakout board for ST’s VL53L1X laser-ranging sensor, which offers fast and accurate ranging up to 4 m. It uses the time of flight (ToF) of invisible, eye-safe laser pulses to measure absolute distances independent of ambient lighting conditions and target characteristics like color, shape, and texture (though these things will affect the maximum range). The VL53L1X also features a programmable region of interest (ROI), so the full field of view can be reduced or divided into multiple zones. Distance measurements can be read through a digital I²C interface. The board includes a 2.8 V linear regulator and level-shifters that allow it to work over an input voltage range of 2.6 V to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

The VL53L1X from ST Microelectronics is a long-distance ranging time-of-flight (TOF) sensor integrated into a compact module. This board is a carrier for the VL53L1X, so we recommend careful reading of the VL53L1X datasheet (1MB pdf) before using this product.

The VL53L1X is effectively a tiny, self-contained lidar system featuring an integrated 940 nm Class 1 laser, which is invisible and eye-safe. Unlike conventional IR sensors that use the intensity of reflected light to estimate the distance to an object, the VL53L1X uses ST’s FlightSense technology to precisely measure how long it takes for emitted pulses of infrared laser light to reach the nearest object and be reflected back to a detector. This approach ensures absolute distance measurements independent of ambient lighting conditions and target characteristics (e.g. color, shape, texture, and reflectivity), though these external conditions do affect the maximum range of the sensor, as do the sensor configuration settings.

Under favorable conditions, such as low ambient light with a high-reflectivity target, the sensor can report distances up to 4 m (13 ft) with 1 mm resolution. See the datasheet for more information on how various external conditions and sensor configurations affect things like maximum range, repeatability, and ranging error. The minimum ranging distance is 4 cm; inside of this range, the sensor will still detect a target, but the measurement will not be accurate. Ranging measurements are available through the sensor’s I²C (TWI) interface, which is also used to configure sensor settings, and the sensor provides two additional pins: a shutdown input and an interrupt output.

The VL53L1X offers three distance modes: short, medium, and long. Long distance mode allows the longest possible ranging distance of 4 m, but the maximum range is significantly affected by ambient light. Short distance mode is mostly immune to ambient light, but the maximum ranging distance is typically limited to 1.3 m (4.4 ft). The maximum sampling rate in short distance mode is 50 Hz while the maximum sampling rate for medium and long distance modes is 30 Hz. Performance can be improved in all modes by using lower sampling rates and longer timing budgets (as can be seen in the figure above).

For advanced applications, the VL53L1X supports configurable thresholds that can be used to trigger interrupts when a target is detected below a certain distance, beyond a certain distance, outside of a range, or within a range. It also supports an alternate detection mode that generates an interrupt when no target is present. Additionally, unlike its predecessors, the VL53L1X supports a configurable region of interest (ROI) within its full 16×16 sensing array, allowing you to reduce the field of view (FoV). With all 265 detection elements enabled, the FoV is 27°. An “Autonomous Low Power” mode that is specially tuned for advanced presence detection is available. This mode allows for significant system power saving by switching off or waking up the host automatically when a human or object is detected within the configured distance thresholds in the region of interest.

The VL53L1X is a great IC, but its small, leadless, LGA package makes it difficult for the typical student or hobbyist to use. It also operates at a recommended voltage of 2.8 V, which can make interfacing difficult for microcontrollers operating at 3.3 V or 5 V. Our breakout board addresses these issues, making it easier to get started using the sensor, while keeping the overall size as small as possible.

The carrier board includes a low-dropout linear voltage regulator that provides the 2.8 V required by the VL53L1X and allows the sensor to be powered from a 2.6 V to 5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 3.3 V or 5 V systems, and the board’s 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards. The board ships fully populated with its SMD components, including the VL53L1X, as shown in the product picture.

For for similar but shorter-range sensors, see our 200 cm VL53L0X carrier and 60 cm VL6180X carrier. Both of these are physical drop-in replacements for the VL53L1X carrier, but they have different APIs, so software for the VL53L1X will need to be rewritten to work with the VL53L0X or VL6180X.

Features and specifications

Dimensions: 0.5″ × 0.7″ × 0.085″ (13 mm × 18 mm × 2 mm)

Weight without header pins: 0.5 g (0.02 oz)

Operating voltage: 2.6 V to 5.5 V

Supply current: ~15 mA (typical average during active ranging at max sampling rate)

Varies with configuration, target, and environment; peak current can reach 40 mA

Varies with configuration, target, and environment; peak current can reach 40 mA

Fast and accurate ranging with three distance mode options:

Short: up to ~130 cm, 50 Hz max sampling rate; this mode is the most immune to interference from ambient light

Medium: up to ~300 cm in the dark, 30 Hz max sampling rate

Long: up to 400 cm in the dark, 30 Hz max sampling rate

Short: up to ~130 cm, 50 Hz max sampling rate; this mode is the most immune to interference from ambient light

Medium: up to ~300 cm in the dark, 30 Hz max sampling rate

Long: up to 400 cm in the dark, 30 Hz max sampling rate

Minimum range: 4 cm (objects under this range are detected, but measurements are not accurate)

Emitter: 940 nm invisible Class 1 VCSEL (vertical cavity surface-emitting laser) – eye-safe

Detector: 16×16 SPAD (single photon avalanche diode) receiving array with integrated lens

Typical full field of view (FoV): 27°

Programmable region of interest (ROI) size on the receiving array, allowing the sensor FoV to be reduced

Programmable ROI position on the receiving array, allowing multizone operation control from the host

Typical full field of view (FoV): 27°

Programmable region of interest (ROI) size on the receiving array, allowing the sensor FoV to be reduced

Programmable ROI position on the receiving array, allowing multizone operation control from the host

Configurable detection interrupt thresholds for implementing autonomous low-power presence detection:

target closer than threshold

target farther than threshold

target within distance window

target outside of distance window

no target

target closer than threshold

target farther than threshold

target within distance window

target outside of distance window

no target

Output format (I²C): 16-bit distance reading (in millimeters)

Included components

A 1×7 strip of 0.1″ header pins and a 1×7 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards, or you can solder wires directly to the board itself for more compact installations.

VL53L1X Time-of-Flight Distance Sensor Carrier with included header pins.

VL53L1X Time-of-Flight Distance Sensor Carrier in a breadboard.

The board has two mounting holes spaced 0.5″ apart that work with #2 and M2 screws (not included).

Important note: This product might ship with a protective liner covering the sensor IC. The liner must be removed for proper sensing performance.

Connections

At least four connections are necessary to use the VL53L1X board: VIN, GND, SCL, and SDA. The VIN pin should be connected to a 2.6 V to 5.5 V source, and GND should be connected to 0 volts. An on-board linear voltage regulator converts VIN to a 2.8 V supply for the VL53L1X IC. Note that if your input voltage is under 3.5 V, you can connect it directly to VDD instead to bypass the regulator; in this configuration, VIN should remain disconnected.

The I²C pins, SCL and SDA, are connected to built-in level-shifters that make them safe to use at voltages over 2.8 V; they should be connected to an I²C bus operating at the same logic level as VIN.

The XSHUT pin is an input and the GPIO1 pin is an open-drain output; both pins are pulled up to 2.8 V by the board. They are not connected to level-shifters on the board and are not 5V-tolerant, but they are usable as-is with many 3.3 V and 5 V microcontrollers: the microcontroller can read the GPIO1 output as long as its logic high threshold is below 2.8 V, and the microcontroller can alternate its own output between low and high-impedance states to drive the XSHUT pin. Alternatively, our 4-channel bidirectional logic level shifter can be used externally with those pins.

Pinout

Schematic diagram

The above schematic shows the additional components the carrier board incorporates to make the VL53L1 easier to use, including the voltage regulator that allows the board to be powered from a 2.6 V to 5.5 V supply and the level-shifter circuit that allows for I²C communication at the same logic voltage level as VIN. This schematic is also available as a downloadable PDF (110k pdf).

I²C communication

The VL53L1X can be configured and its distance readings can be queried through the I²C bus. Level shifters on the I²C clock (SCL) and data (SDA) lines enable I²C communication with microcontrollers operating at the same voltage as VIN (2.6 V to 5.5 V). A detailed explanation of the I²C interface on the VL53L1X can be found in its datasheet (1MB pdf), and more detailed information about I²C in general can be found in NXP’s I²C-bus specification (1MB pdf).

The sensor’s 7-bit slave address defaults to 0101001b on power-up. It can be changed to any other value by writing one of the device configuration registers, but the new address only applies until the sensor is reset or powered off. ST provides an application note (196k pdf) that describes how to use multiple VL53L0X sensors on the same I²C bus by individually bringing each sensor out of reset and assigning it a unique address, and the approach can be easily adapted to apply to the VL53L1X instead.

The I²C interface on the VL53L1X is compliant with the I²C fast mode (400 kHz) standard. In our tests of the board, we were able to communicate with the chip at clock frequencies up to 400 kHz; higher frequencies might work but were not tested.

Sensor configuration and control

In contrast with the information available for many other devices, ST has not publicly released a register map and descriptions or other documentation about configuring and controlling the VL53L1X. Instead, communication with the sensor is intended to be done through ST’s VL53L1X API (STSW-IMG007), a set of C functions that take care of the low-level interfacing. To use the VL53L1X, you can customize the API to run on a host platform of your choice using the information in the API documentation. Alternatively, it is possible to use the API source code as a guide for your own implementation.

Sample code

We have written a basic Arduino library for the VL53L1X, which can be used as an alternative to ST’s official API for interfacing this sensor with an Arduino or Arduino-compatible controller. The library makes it simple to configure the VL53L1X and read the distance data through I²C. It also includes example sketches that show you how to use the library.

We also have an implementation of ST’s VL53L1X API for Arduino available, including an example sketch. Compared to our library, the API has a more complicated interface and uses more storage and memory, but it offers some advanced functionality that our library does not provide and has more robust error checking. Consider using the API for advanced applications, especially when storage and memory are less of an issue.

People often buy this product together with: