Persistence-of-vision, or POV, displays work on the principle that if a light blinks in front of your eye, you perceive it for some amount of time after it’s gone. Blink lights in sequence when moving, and you can create what looks like a static image. “Programmer with a soldering iron” B45i found a deal on ATtiny13 microcontrollers for roughly $.30 each, and was able to create a POV display with one for less than a dollar.