Joe Grand writes in with plans to build his POV wristwatch (mentioned here a while back) –
Five years ago, I designed a prototype for a wristwatch based on the phenomenon of persistence-of-vision. Being a longtime runner, I thought it would be cool to be able to run at night without fumbling with my watch in order to see the elapsed time. The POV Watch was born and it works pretty well, as long as you move your arm fast enough to create the image.
Going through my archives, I realized that this would be a great project to open source, since there are many aspects of the design that people can learn from. The schematic, PCB Gerber plots, and source code are now available on my site.
The design uses a PIC16LF628A chip, SMD LEDs, and a mercury switch to detect the direction of wrist-shake. Download all the pertinent info over at Grand Idea Studios.
Binary POV wristwatch
In the Maker Shed: