The dynacho is an idea that came to me while riding my bicycle home from work. I asked myself, why is it that every stupid bicycle computer has to have a battery and a magnet attached to the front wheel when really all it needs is right on the bike already:
Modern hub dynamos not only provide enough power to suffice such small speedometer devices but also generate an alternating current AC power the frequency of which is a direct result of the speed the wheel is turnig at.
So my basic idea is to build an Arduino powered device that takes power as well as speed information from the AC voltage generated by my hub dynamo.
As soon as I have a working dynacho in my hands, I’ll post a full-length article on how to build your own. Until then, you can follow my progress through the dynacho blog posts. Feel free to comment and: Have fun!