Im looking into getting the L9110S Motor Driver. I need to control 4 motors between 4.5v and 6v. The issue I am running into is how the motor driver is powered. It looks like most people power it directly from the GPIO/Breadboard? Example Video. But im also told that connecting things to the Pi like that is a bad idea, especially with motors.

tl:dr-> This driver only takes one power source, should that be from the Pi/breadboard? Or an external battery (I have a 4 AA battery tray right now).

1 Answer 1


People would probably use a single power supply for convenience when that is possible.

There will be no problem using an external power supply. Just remember that the Pi and motor driver board need to have a common ground. So the L9110S ground needs to be connected to a Pi ground and the power supply ground (perhaps marked -ve).

  • So the power supply sends both + and - (sorry for terminology, im gonna do much more electronics research after I become familiar with python) to the L9110S, the L9 does the same with the motors. But the L9 also has to send a - (ground) to the Pi. Is that all correct? Any resistors needed on the Pi for it?
    – dka13
    Mar 8, 2018 at 22:28
  • That is correct. The grounds of the L9110S and the Pi need to be connected. Otherwise they won't have a common voltage reference and the Pi won't be able to control the L9110S.
    – joan
    Mar 8, 2018 at 22:35

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