MPL3115A2 Register Usage

This project uses only the registers needed for the tutorial measurement path.

Identification

• WHO_AM_I: Confirms that the connected device reports the expected MPL3115A2 identity value before the tutorial continues.

Status

• STATUS: Polled by main() to determine when temperature or pressure data is ready to read.

Pressure Output

• OUT_P_MSB
• OUT_P_CSB
• OUT_P_LSB

These three registers hold the pressure sample. The driver treats the result as a 20-bit Q18.2 value before converting it to pascals and then inHg.

Temperature Output

• OUT_T_MSB
• OUT_T_LSB

These two registers hold the signed 12-bit fixed-point temperature sample. The driver converts the value to degrees Celsius.

Configuration

• PT_DATA_CFG: Enables pressure and temperature data-ready event flags.
• CTRL_REG1: Places the sensor into standby for configuration, then active barometer mode with OSR=128.