[Motor shield 2.0] Only 4V at full output when powered from Arduino with 12V power supply

Discussion in 'Embedded Systems and Microcontrollers' started by sheepjms, Jul 5, 2016.

  1. sheepjms

    Thread Starter New Member

    Jul 5, 2016
    Hello, I'm using the 2.0 motor driver. I have an Arduino (Seeeduino) and the shield on top. The Arduino is powered through its DC jack with a 12V power supply. I have the power select jumper on the shield set because I want to power it from the Arduino. However, even at full speed (100) I can only get 4V at either of the two output channels. Now when I connect the 12V power supply to the power in of the shield, then I get 11.5V at the motor shield output as expected. Any idea why I can't use the shield when powering it from the Arduino? Thanks.
  2. AlbertHall

    Well-Known Member

    Jun 4, 2014
    This, from the motor shield instructions, may be the answer: