This is a playful simple navigation device using a telescope-like cardboard tube, LEDs, and a servo motor with a teeny tiny T-Rex attached to it. This servo only turned 180 degrees, so forward was denoted by green light (3 blinks), backward by blue light (3 blinks). Stop was red light (3 blinks) and final stop was just steady red light. To turn left/right, a green LED to the left/right would blink for 10 seconds, then the servo would point the T-Rex left/right.
Feedback from class was that the dinosaur looked like a horse, because the inside of the housing is quite dark. (Although the element of surprise is fun.) You can see through to the outside world, looking past the dinosaur, but you field of vision is really quite limited. It didn’t work with the Bluetooth dongle, sadly, although it had worked with direct serial-USB connection.