Adafruit barometric pressure altitude temperature sensors adafruit 1893 the adafruit mpl3115a2 i2c barometric pressure altitude temperature sensors use only 2 x gpio pins i2c and provide you with precision air pressure measurements each board contains a 33v regulator an i2c level shifter and pull up resistors on the i2c bus making it 5v ready theres an interrupt pin which goes active when data is available plus a 32 sample fifo which lets the sensor record samples automatical