Dual VNH 5019 motor driver shield not working

Hey everyone.

I’ve got the dual vnh 5019 motor driver shield stacked with my arduino UNO r3, I’ve soldered all of the pins in place per the instruction manual, I have 12v running to the motor shield, and 2 12v pololu 19:1 motors connected to the shield as well

I cannot get anything out of the motors, not even indicator LEDs for the Demo code from the motor shield’s library. The blue LED to indicate power is the only thing I can get out of the motor shield. I’ve been at this for weeks to no avail, and it would be fantastic to figure this out.

Hello.

I am sorry you are having a problem using your dual VNH5019 shield. Could you measure the voltage of both your logic input and your motor power? Could you also try running the demo code with the motors disconnected and see if the red and green direction LEDs light? Could you post close-up pictures of the underside of your motor driver shield that show the solder joints?

Grant

Hey grant,
Sorry for the delay, I missed the notification! I got it to power on, and the indicator LEDs light up when I test it, but the 19:1 gearmotors don’t move at all. I have 8 3.7v 18650 batteries connected in series running to the VIN/Ground on the motor shield. It’s tough to take apart the assembly I’ve got it attached to, but I did resolder all of the connections just to be sure they’re solid.

Hello.

The power setup you described is different than what your pictures appear to show. Do you really have all the batteries in series? If you have 8 3.7V batteries in series, that would give you 29.6V nominally and the actual voltage could be several volts higher when charged. This voltage is high enough to trigger the overvoltage shutdown on the driver. You should use a voltage that is within the 5.5V to 24V operating range of the motor driver shield. Also, you should check to make sure you are supplying an appropriate voltage for your Arduino as well.

Separately, do your gearmotors run if you apply voltage to them directly?

Grant

No no, my mistake, there are 4 and 4, wired in parallel, so the voltage is 14.4 total, just more battery capacity. The motors do run when power is applied directly.

Thank you for clarifying that. Could you post close up pictures showing both sides of the motor driver shield?

By the way, while the Arduino Uno does have a 20V input voltage limit, Arduino recommends that the input voltage be between 7 - 12V.

Grant