Peter Todd petertodd.ca> writes: > Anyone know of a good reference > to learn more about this stuff? All my google searches hasn't turned up > anything more advanced than "chopper drives control current by turning > the voltage on and off rapidly" I found these useful: http://www.cs.uiowa.edu/~jones/step/highlevel.html http://users.pandora.be/educypedia/electronics/motorstep.htm Sergey Dryga -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist