I'm using the Uno R3 with this motor shield,
http://yourduino.com/sunshop2/index.php?l=product_detail&p=292
Schematic diagram
I have removed the power jumper from the motorshield because I have a separate power supply for the motorshield, but when I plug in the usb cable to the Arduino, I get a small amount of power to the motorshield, causing the stepper to vibrate, even when I have removed the battery from the motorshield.
How do I keep the usb power from powering the motorshield?
Thanks....