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 some upsides compared to the BMP180, 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).
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.
chip looks and sounds a whole lot like the MPL115A2 but this is the
precision version, which can act as an altitude-sensor as well as
Using the sensor is easy. For example, if you're using
an Arduino, simply connect the VDD pin to the 5V voltage pin, GND to
ground, SCL to I2C Clock (Analog 5 on an UNO) and SDA to I2C Data
(Analog 4 on an UNO). Then download our MPL3115A2 Arduino library and
example code for temperature, pressure and basic altitude calculation.
Install the library, and load the example sketch. Immediately you'll
have the temperature, pressure and altitude data printed in the serial
console.Technical details:MPL3115A2 Datasheet
- Dimensions: 18mm x 19mm x 2mm / .7" x .8" x .1"
- Weight: 1.2g
- Vin: 3 to 5.5 VDC
- Logic: 3 to 5V compliant
- Pressure sensing range: 50-110 kPa (up to 10Km altitude)
- 1.5 Pa / 0.3 m altitude resolution
-This board/chip uses I2C 7-bit address 0x60