The SW03 xChip is equipped with a weather sensor that is capable of measuring the temperature, atmospheric pressure and altitude. It is based on the MPL3115A2 manufactured by NXP Semiconductors.
The MPL3115A2 is a compact, piezoresistive, absolute pressure sensor with an I2C digital interface. MPL3115A2 has a wide operating range of 20 kPa to 110 kPa, a range that covers all surface elevations on earth. The MEMS is temperature compensated utilizing an on-chip temperature sensor. The pressure and temperature data is fed into a high resolution ADC to provide fully compensated and digitized outputs for pressure in Pascals and temperature in °C. The compensated pressure output can then be converted to altitude.