This project was made to fulfill a need at the lab I work in. We have live camera feeds watching over testing to ensure everything is going well, but sometimes these cameras freeze, and there is really no way to notice. That's where this device comes in. It shows a rotating light pattern that shows up on the camera feed. As long as the lights keep spinning, you know that the camera is still working.
Here are photos of the device:
And here is the device in action:
The circuit design and programming is pretty simple. The ATtiny sends binary commands to the shift register telling it which LED to light up at which time. The main challenge was designing the traces such that everything would fit in the circular pattern with as few jumpers as possible.
The code and schematic can be obtained here: https://github.com/jerwil/CameraShow