Trig:
I'd think that this is a common question however I didn't find any posts describing my difficulties.I've got a stepper motor:
Stepper Motor - 125 oz.in (200 steps/rev, 600mm Wire) - ROB-13656 - SparkFun ElectronicsAn Arduino Uno and the ArduinoMotorShield.
I've got it power from the onboard power, also tried a 12v 1a power supply. I'm connecting the motor directly to the shield, no resistors in line (as I don't think the power supply is strong enough to overpower the board or the motor).
Firstly lets clarify the power situation. The motor is 3V 2A - commonly this would be driven from a chopper driver since its low impedance windings.
When you say "onboard power" what is the actual power supply ratings?
When you try to run a 3V 2A motor from 12V 1A power supply you expect things to work? Really?
[Oh yes, and which motor shield exactly? IE there's no link for that]