I2C is a common electronic communication standard that allows a leader device, the Hubs, to communicate with multiple devices, followers, attached to the same port. Each connector on a Hub is a separate I2C bus and many different sensors can be connected to each of the four I2C busses available on both the Control Hub and Expansion Hub. Every I2C follower device has an unique address, a number, which is normally fixed by the manufacturer.All of the devices on an individual I2C bus must have a unique address so that the master can communicate with one sensor at a time. If two devices have the same address, such as when using two of the same kind of sensor, they must be used on different I2C busses.
The I2C Bus 0 hosts the internal IMU sensor within the Hubs. A REV Robotics Color Sensor (REV-31-1557) or a 2m Distance Sensor (REV-31-1505) can be added to I2C Bus 0. The steps below walk through adding a color sensor to Bus 0.
Step 1: Click I2C Bus 0 to launch the configuration screen. As you can see the IMU sensor is already configured to this bus.
Step 2: Press the Add button to add the Color Sensor to this bus. Select "REV Color/Range Sensor" from the drop down menu and name the device.
Step 3: When you have finished configuring the sensor hit 'Done.' The app will return to the previous screen.