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.

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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:

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: