Life has its ups and downs, so why not measure them? The MPL3115A2 is a MEMS pressure sensor that provides Altitude data to within 30cm (with oversampling enabled). The sensor outputs are digitized by a high resolution 24-bit ADC and transmitted over I2C, meaning it’s easy to interface with most controllers. Pressure output can be resolved with output in fractions of a Pascal, and Altitude can be resolved in fractions of a meter. The device also provides 12-bit temperature measurements in degrees Celsius.

This breakout board makes it easy to prototype using this tiny device by breaking out the necessary pins to a standard 0.1" spaced header. The board also has all of the passive components needed to get the device functioning, so you can simply connect it to something that talks I2C and get to work!

Features

1.95V to 3.6V Supply Voltage, internally regulated by LDO

1.6V to 3.6V Digital Interface Supply Voltage

Fully Compensated internally

Direct Reading, Compensated

Pressure: 20-bit measurement (Pascals)

Altitude: 20-bit measurement (meters)

Temperature: 12-bit measurement (degrees Celsius)

Pressure: 20-bit measurement (Pascals)

Altitude: 20-bit measurement (meters)

Temperature: 12-bit measurement (degrees Celsius)

Programmable Events

Autonomous Data Acquisition

Resolution down to 1 ft. / 30 cm

32 Sample FIFO

Ability to log data up to 12 days using the FIFO

1 second to 9 hour data acquisition rate

I2C digital output interface (operates up to 400 kHz)

The SparkFun BME280 Atmospheric Sensor Breakout is the easy way to measure barometric pressure, humidity, and temperature readings all without taking up too much space. Basically, anything you need to know about atmospheric conditions you can find out from this tiny breakout. The BME280 Breakout has been design to be used in indoor/outdoor navigation, weather forecasting, home automation, and even personal health and wellness monitoring.

The on-board BME280 sensor measures atmospheric pressure from 30kPa to 110kPa as well as relative humidity and temperature. The breakout provides a 3.3V SPI interface, a 5V tolerant I2C interface (with pull-up resistors to 3.3V), takes measurements at less than 1mA and idles less than 5µA. The BME280 Breakout board has 10 pins, but no more than six are used at a single time. The left side of the board provide power, ground, and I2C pins. The remaining pins which provide SPI functionality and have another power and ground, are broken out on the other side.

Note: The breakout does NOT have headers installed and will need to purchased and soldered on yourself. Check the Recommended Products section below for the type of headers we use in the Hookup Guide!

Features

Operation Voltage: 3.3V

I2C & SPI Communications Interface

Temp Range: -40C to 85C

Humidity Range: 0 - 100% RH, =-3% from 20-80%

Pressure Range: 30,000Pa to 110,000Pa, relative accuracy of 12Pa, absolute accuracy of 100Pa

Altitude Range: 0 to 30,000 ft (9.2 km), relative accuracy of 3.3 ft (1 m) at sea level, 6.6 (2 m) at 30,000 ft.

Incredibly Small

The SparkFun Soil Moisture Sensor is a simple breakout for measuring the moisture in soil and similar materials. The soil moisture sensor is pretty straight forward to use. The two large exposed pads function as probes for the sensor, together acting as a variable resistor. The more water that is in the soil means the better the conductivity between the pads will be and will result in a lower resistance, and a higher SIG out.

To get the SparkFun Soil Moisture Sensor functioning all you will need is to connect the VCC and GND pins to your Arduino-based device (or compatible development board) and you will receive a SIG out which will depend on the amount of water in the soil. One commonly known issue with soil moisture senors is their short lifespan when exposed to a moist environment. To combat this, we’ve had the PCB coated in Gold Finishing (ENIG or Electroless Nickel Immersion Gold). We recommend either a simple 3-pin screw pin terminal or a 3-pin jumper wire assembly (both can be found in the Recommended Products section below) to be soldered onto the sensor for easy wiring.

Note: Check the Hookup Guide below for assembly and weatherproofing instructions as well as a simple example project that you can put to together yourself!

Get Started with the Soil Moisture Sensor Guide

The Si7021 is a low-cost, easy-to-use, highly accurate, digital humidity and temperature sensor. This sensor is ideal for environmental sensing and data logging and perfect for build a weather stations or humidor control system. All you need are two lines for I2C communication, and you’ll have relative humidity readings and very accurate temperature readings as a bonus!

There are only four pins that need to be hooked up in order to start using this sensor in a project. One for VCC, one for GND, and two data lines for I2C communication. This breakout board has built-in 4.7KΩ pullup resistors for I2C communications. If you’re hooking up multiple I2C devices on the same bus, you may want to disable these resistors.

Features

0.6" x 0.6"

The SHT15 Breakout is an easy to use, highly accurate, digital temperature and humidity sensor. This board has been fully calibrated and offers high precision and excellent long-term stability at low cost. The digital CMOSens® technology integrates two sensors and readout circuitry on one single chip. All you need is two lines for 2-wire communication, and you’ll have relative humidity and temperature readings to help you sense the world around you!

The two sensors built into the SHT15 have been seamlessly coupled to a 14bit analog to digital converter and a serial interface circuit resulting in superior signal quality, fast response time, and a strong resistance to external disturbances. Additionally, the on board SHT15 features a 0-100% RH measurement range with a temperature accuracy of +/- 0.3°C @ 25°C. There are only four pins that need to be hooked up in order to start using this sensor in a project. One for VCC, one for GND, and the two data lines SDA and SCL.

Features

Operating Voltages: 2.4V min - 5.5V max

2 factory calibrated sensors for relative humidity & temperature

Digital 2-wire interface (Not I2C, but similar)

Measurement range: 0-100% RH

Absolute RH accuracy: +/- 2% RH (10…90% RH)

Repeatability RH: +/- 0.1% RH

Temp. accuracy: +/- 0.3°C @ 25°C

Precise dewpoint calculation possible

Fast response time

Low power consumption (typ. 30 µW)

Need to measure something damp? This epoxy-coated precision 1% 10K thermistor is an inexpensive way to measure temperature in weather or liquids. The resistance in 25 °C is 10K (+- 1%). The resistance goes down as it gets warmer and goes up as it gets cooler. For specific temperature-to-resistance, check the lookup table.These are often used for air conditioners, water lines, and other places where they can get damp. The PVC coating of the wires is good up to 105 °C so this isn't good for very hot stuff.We even toss in an additional 1% 10K resistor which you can use as calibration or for a resistor divider.We have a great detailed tutorial on how thermistors work and how to use this one with both Arduino & CircuitPython!

Take your next ourdoor sensor project to the next level with a SHT-10 based temperature/humidity sensor. The sensor includes a dual-use sensor module from Sensiron in a sintered metal mesh encasing. The casing is weatherproof and will keep water from seeping into the body of the sensor and damaging it, but allows air to pass through so that it can measure the humidity outside. While it is designed to be submersible in water, it's always best to avoid long-term (over 1 hour at a time) submersion, and it obviously would only give you temperature readings. For that, our metal-cased temperature sensors would be better! This sensor is best for simply placing outside for exterior weather sensing.Humidity readings have 4.5% precision, temperature is 0.5% precision. A microcontroller is required to interface. The sensor is not washed after reflow and is rehydrated according to datasheet requirements.The sensor is essentially just a Sensiron SHT-10 with the 4 data/power wires brought out so any SHT-1X code for a microcontroller will work. The sensor works with 3 or 5V logic. The 1 meter long cable has four wires: Red = VCC (3-5VDC), Black or Green = Ground, Yellow = Clock, Blue = Data. For Arduino, there's a handy Sensiron library with example. For Propeller, there's an SHT1X sensor object. Don't forget to connect a 10K resistor from the blue Data line to VCC.

Soil Temperature/Moisture Sensor (8:52)