 This is the Arduino used as a lighting generator. Each of the green LEDs represents a room light in a building. So it's randomly sequencing through, turning room lights on and off, leading them on for 60% of the cycle, as if the person had gone into the room and stayed there. But the pattern itself and the duration is all set with a pseudo-random sequence. So it would take a long, long time to see the cycle repeat, and not just two to the sixteenth states, because the time, the duration is also random. So you really would be waiting a long time to see the cycle repeat exactly the way it started. It can be switched on and off by switching on and off the Arduino controller.