As an introduction to computers, the kids and I have been building the SpokePOV. The kids have been into bicycle projects this summer, so this is a great crossover project.
Photo of completed project from ladyada.net:
We are using green LEDs and hope ours will be this cool!
We ordered the kit with the extra ROM so we animate the images. We picked up some 96/4 tin/silver solder from Radio Shack. It is lead free, so I don’t mind the kids using it.
The SpokePOV uses an ATMEL ATtiny2313 microcontroller and and has two rows of 30 LEDs. The LEDs blink out a pattern as the wheel spins that the eye perceives as a complete picture (follow the above links for action photos). There is a hall-effect sensor, so the processor can sense the wheel rotation and calculate how fast it is spinning, to create the proper pattern.
So far, we have a completed circuit board. There is a Windows program to create the images and download to the Spoke POV. We’re having a bit of trouble with that.