Testing for Echo
The Ping))) Ultrasonic Distance Sensor lets your ActivityBot detect obstacles and measure the distance to them. Even though the PING))) sensor looks a bit like eyes, it is more like a mouth and an ear.
Much like a bat, the PING))) sensor emits an ultrasonic chirp when triggered, then listens for the chirp's echo and signals its return. The Propeller microcontroller can mark the time between triggering the PING))) sensor and getting a return signal. This echo return time can then be used to calculate the distance to an object.
This ability makes different ActivityBot navigation strategies possible, such as avoiding obstacles while roaming, or maintaining a set distance to an object that is moving.