Connecting the Arduino Yún and Uno boards
We are not done yet! For now, there are no connections between the Arduino Yún and the Arduino Uno board, so the Yún board won't be able to access the DC motors and the sensors of the robot. To solve this issue, the first step is to connect the power from the Arduino Uno board to the Yún board. This way, when we power the project using the battery, the Yún board will be powered as well.
To do so, simply connect the ground pins together and plug the Vin pin on the Arduino Yún to the 5V rail of the Arduino Uno, as shown in the following image:
To finish connecting the two Arduino boards, we need to connect them ...