johnwasser:
Yes. Be sure to set pins 3 and 11 (PWM-A and PWM-B) to HIGH to turn on power. You should probably also turn 8 and 9 to LOW to turn off the brakes.
Ugh. This was exactly my problem. Wish there was more documentation about the motor shield. Thanks, John.
johnwasser:
If you want to hold position without heating up the stepper you can use analogWrite() on 3 and 11 to reduce the power. If you want to release the motor so you can turn the shaft by hand, set 3 and 11 to LOW.
Can you talk more about this? If most of the time, my stepper's going to be stationary, should I be setting it to LOW manually (and only doing a .step() when I actually want to move it, then analogWrite(3,LOW))?