I’ve been using a Seeed motor shield V2 in an attempt to drive two dc motors simultaneously, but am having trouble determining what power sources should be used and where. Online documentation indicates that the preferred way is to power both the arduino (seeeduino) and motor shield independently by removing the jumper (power supply connector). The wiki page for the motor shield, however, at ( seeedstudio.com/wiki/Motor_Shield_V2.0 ) make allusions to the fact that the jumper isn’t functional. Indeed, when I tried connecting a 9V battery to the motor shield, it worked (powered both the shield and arduino) until I tried removing the jumper, at which point both lost power. Trying to actually drive the motors using the single power source (going through the motor shield) didn’t work, and caused the LEDs on the shield to flicker. Right now, the best I can do is supply the arduino using both a 9V and USB, or power both the arduino and shield using separate 9V batteries with the jumper still installed, which I feel has the potential to do harm to the arduino.
Thanks for your help.