For our Robotic class we were tasked to right the code of a Zumo bot to make it fight in the Arena against other Zumo bots, and push them off the ring.
Zumo bots have lots of already implemented captors such as border detection (to not get out of the ring which is delimited by a white border), accelerometer (is your bot being pushed by another bot), a buzzer (for victory song which of course we decided was gonna be the Mario song in our case) ...
We wanted to give our robot sight. We followed this tutorial and welded to the zumo bot wires connected to an ultrasonic sensor.
Our bot has the ability to detect white borders on a black ground and turn to drive away from the border to stay in the ring (so he could basically drive on a highway for sure), he can detect objects using his ultrasonic sensor in a way that if he sees any robot passing 8 cm in front of him he will accelerate to push him off the line, and he will sing his Mario battle song the all time. Isn't he amazing !!