[foobert]

if you tried to control a motor directly with the vex controller it would suck enough amps through the poor dear to release all of its magic smoke.

if you take the back off of a vex motor, you'll find a little 8 pin pic on a circuit board that is impossible to pry out of the housing because the motor is soldered to the other side. also on the other side, (if you pry a lot, like i did), is a larger chip with many legs. i'm guessing this is a monolithic h-bridge. if the little 8 legged pic tried to drive the motor directly, it, too, would lose all its magic smoke.

so, we've got an eight legged pic. that's certainly enough for power, (bet there's a regulator on that little circuit board, too), ground, three pins to control the h-bridge, and something left over for feedback from the motor so the little pic can say, "ok, if you give me a 1ms pulse i'm going to spin this thing at 100 rpm in reverse, if you give me a 1.5ms pulse i'm not going to spin it at all and if you give me 2ms i'll spin it 100 rpm forward."

reckon i ruined that motor, too.