This pressure sensor from Freescale is a great low-cost sensing solution for precision measurement of barometric pressure and altitude. The MPL3115A2 has a typical 1.5 Pascal resolution, which can resolve altitude at 0.3 meters (compare to the BMP180 which can do 0.17m). It has the same upsides compared to BMP280, such as interrupt outputs for ultra-low power usage, and its also a heck of a lot easier to read altitude with a built in altimeter calculation – no calibration reading and calculating required. As a bonus, there’s even a fairly good temperature sensor with ±1°C typical accuracy (±3°C max).
This chip likes to be used with 2-3.6V power and logic voltages, so we placed it on a breakout with a 3V regulator and logic level shifting. Its easy to use with any Arduino or microcontroller that has i2c capability.
- V2.0 version added power conversion module and IO port level conversion circuit for the 3.3V MCU and 5V chip
- Resolution:< 1 feet /0.3 M
- Pressure range: 20 – 110 kPa
- Compensation, direct reading (don’t need software):
- 20bit pressure measurement (Pascal)
- 20bit measurements of height (metres)
- 12bit temperature measurement
- Onboard intelligence
- Sampling rate: maximum 128 Hz