For advanced features, the remote control has a three-axis gyro integrated with a three-axis accelerometer (U3).
Figure 1. Motion tracking device
The circuit is connected to the MCU by the first I2C. If you want to use the second I2C, there are four solder bridges that you need to change. SB10 and SB11 have to be soldered and SB8 and SB9 have to be cut. This circuit is a ±250° per sec/±500° per sec/±1000° per sec/±2000° per sec selectable three-axis gyro and a ±2 g/±4 g/±8 g/±16 g selectable three-axis accelerometer.