Barometric Pressure, Altitude & Temperature Sensor

Barometric Pressure, Altitude & Temperature Sensor – I2C

This pressure sensor from Freescale is an ideal and cheap sensing solution to measure altitude and barometric pressure with precision.

The MPL3115A2 offers a typical 1.5 Pascal resolution that resolves altitude at 0.3 meters (the BMP180 can do 0.17m). Compared to the BMP180, the MPL3115A2 grants several advantages:

• interrupt outputs in case of ultra-low power usage,
• a built-in altimeter calculation for an easier reading of altitude,
• no calibration reading and calculating required.
• Furthermore, a fairly good temperature sensor, with ±1°C typical accuracy (±3°C max) is an additional bonus.

This chip prefers 2-3.6V power and logic voltages, so it is placed on a breakout with logic level shifting and a 3V regulator. Easy to use with any Arduino or any microcontroller with I2C capability.

Although this chip may appear very similar to the MPL115A2, it is the precision version. The MPL3115A2 can function as an altitude-sensor and also as a barometer.

The use of this sensor is definitely easy. If you are using an Arduino, for example, simply connect to the 5V voltage pin the VDD pin, GND to ground, SCL to I2C Clock (Note: Analog 5 on an UNO) and SDA to I2C Data (Note: Analog 4 on an UNO). After that, download Adafruit’s MPL3115A2 Arduino library and example code for pressure, temperature and basic altitude calculation. After installing the library, load the example sketch. You will have pressure, temperature and altitude data all printed in the serial console at once.

Adafruit name: MPL3115A2 – I2C Barometric Pressure/Altitude/Temperature Sensor [ADA1893]