BMP180 Barometric Pressure Sensor

This pressure sensor is a BMP180 based digital barometric pressure sensor module and is functional compatible with older BMP-085 digital pressure sensor with less power consumption smaller in size and more accurate. BMP180 combines barometric pressure, temperature and altitude. The I2C allows easy interface with any microcontroller. On board 3.3V LDO regulator makes this board fully 5V supply compatible. BMP-180 can measure pressure range from 300 to 1100hPa (+9000m to -500m relating to sea level) with an accuracy down to 0.02hPa (0.17m) in advance resolution mode. BMP-180 is an improved replacement for BMP-085 sensor. BMP-180 uses piezo-resistive technology for high accuracy, linearity, EMC robustness and stability for a longer period of time.

Specifications:

• Supply Voltage:1.8V to 3.6V
• Low power consumption:0.5uA at 1Hz
• I2C interface
• Max I2C Speed: 3.5Mhz
• Very low noise:up to 0.02hPa (17cm)
• Pressure Range: 300hPa to 1100hPa (+9000m to -500m)

Working of BMP180

The BMP180 consists of a piezo-resistive sensor, an analog to digital converter and a control unit with E2PROM and a serial I2C interface. The BMP180 delivers the uncompensated value of pressure and temperature.The microcontroller sends a start sequence to start a pressure or temperature measurement. After converting time, the result value (pressure or temperature respectively) can be read via the I2C interface. For calculating temperature in °C and pressure in hPa, the calibration data has to be used. These constants can be read out from the BMP180 E2PROM via the I2C interface at software initialization.The sampling rate can be increased up to 128 samples per second (standard mode) for dynamic measurement. In this case, it is sufficient to measure the temperature only once per second and to use this value for all pressure measurements during the same period.