Gravity MAX30102 Heart Rate & Oximeter Sensor DFRobot Gravity MAX30102 Heart Rate and Oximeter Sensor integrate the Maxim MAX30102 chip and an MCU with heart rate and blood oxygen algorithm. The MAX30102 uses PPG(PhotoPlethysmoGraphy) to measure data. This is converted into heart rate and oximetry values when processed by the MCU. It is then output through I2C or UART making the sensor easy to use and greatly reducing resource occupation of the main controller.