Step 7: Application: talking to other modules using I²C
Using I2C allows for directly addressing up to 127 "slave" boards. Here the board on the right side in the video is the "master" (which initiates all transfers), the left board is the slave (waiting for data). I2C needs 2 signal lines and the usual power lines (+, -, SDA, SCL). As it is a bus, all devices are connected to it in parallel.