PicOx - Open Source Motor Controller for Electric Bike

 Have a look at the construction details of this Open Source Electric Bike Motor Controller. There are good circuit construction details and diagrams on the creators site.
More details are available on these pages:
http://www.theworkshop.ca/energy/picox/2/picox2.htm
http://www.theworkshop.ca/energy/picox/3/picox3.htm
http://www.theworkshop.ca/energy/picox/4/picox4.htm
"In brief the PicOx is a PicAxe 08M based digital Controller that performs an ADC of a Hall-effect throttle and [...]