In-Depth: Interface BMP180 Barometric Pressure & Temperature Sensor with Arduino

This project interfaces a BMP180 barometric pressure and temperature sensor module with an Arduino board to measure atmospheric metrics. The BMP180 sensor integrates a piezoresistive pressure sensor, an analog-to-digital converter, and a control unit with a built-in EEPROM containing calibration coefficients. Communication between the Arduino board and the BMP180 module is handled via the I2C protocol, which requires only two data lines—Serial Data (SDA) and Serial Clock (SCL)—alongside power and ground jumper wires. When the system runs, the Arduino queries the BMP180 for raw temperature and pressure readings. Because raw sensor outputs are affected by ambient temperature variations, the Arduino applies mathematical compensation algorithms utilizing the unique calibration data stored within the sensor's internal memory. The Adafruit BMP085 Library, supported by the Adafruit Unified Sensor Driver and Adafruit Bus IO Library, manages the low-level register communication and handles the complex math required to convert the raw electrical signals into standard engineering units. The resulting barometric pressure can also be used alongside sea-level pressure formulas to calculate approximate altitude.