This week's focus was on output devices. Not surprisingly, the assignment was to design and build some electronics for displaying and actuating in response to input from a sensor. I set out to build a persistence-of-vision (POV) display for my bike spokes. POV displays form images by moving light-sources fast enough that they persist as lines, while modulating their brightness fast enough to form coherent images. Such displays have been put on bike wheels before, and there are even kits available for those without access to milling machines.

I wanted to vinyl cut the circuit so that it could be long enough to span a spoke, but worried that the trace wouldn't be able to withstand environmental stresses.