I have a break from school coming up and I'm planning on building a persitance of vision (POV) toy for my front wheel from scratch. There are some guides online for this, but I"m planning on designing it myself. If you don't know they look like this www.ladyada.net/images/portfolio/spokepov.jpg when rotating quickly enough, and are made up of a row of LEDs that flash patterns over time. They work for the same reason that cartoons work - they move more quickly than your eye's "refresh rate"
The electronics are going to look like this:
1 Arduino micro (about the size of a stick of gum and negligable weight
1 Hall effect sensor + magnet (the same type of sensor that sits on the fork and speaks to your bike computer - used to synchronize the display so that it can be stationary relative to the bike)
8 red LEDs (placed on the outernmost part of the spokes for writing messages)
11 yellow LEDs (the rest of the inside of the wheel, for displaying patterns)
The whole device will be mounted on a hand soldered demo board
I'm pretty confident on the electronics, except maybe that the yellow LEDs won't be dense enough - though I'm willing to take critiques at this point as well.
I'm hoping that you guys can help out more with some of the following questions:
What's the best way to attach the whole device to the spokes? Note that my wheels have a somewhat ununusual spoke arrangement.
What's the best way to protect and house the device?
Are there any potential legal/safety issues with having flashing lights on the wheel? I live in Israel, so I appreciate that probably nobody will know about the legal aspects - but am I putting myself or anyone else in danger? The LEDs are only 1200 (yellow) and 1500 (red) mcd - which I am hoping is a good middle ground between visible and blinding.