Pololu Dual VNH5019 Motor Driver Shield Troubleshooting

I have attached the Dual VNH5019 Motor Driver Shield to my Arduino UNO as shown on the user guide. I am currently attempting to power one 131:1 Metal Gearmotor 37Dx57L mm which is attached to the M1 terminals on the shield. I have the Arduino connected to my computer through the USB port, and I’m attempting to power the shield using a 0-16V power supply (the short is not currently attached). I have uploaded the demo program from the motor driver library, but every time I try to run the program, it says I have a fault on M1, and the motor will not move at all. I know that the power supply is working because the motor power light turns on. I know the motor itself works because when connected to the power supply on its own, it will move. When I disable the stopIfFault() method in the demo program, the serial monitor just says the current on M1 is 0. Anyone have any ideas what might be wrong?


Could you tell me some more about your setup? What voltage is your over supply set to? Can you post pictures showing the soldering on your board?


My voltage supply can be set to up to 15V. Here is a picture of the soldering on the board: https://goo.gl/photos/ddtsjNL8ryNYb4Jx6. Thanks for the quick response!

Update: By some miracle, the second motor started working without me having changed anything that I know of. I tried to fix the solder on the first motor to get it to work, but now only the first motor does what the demo program says it is supposed to, while the second motor only spins one direction and does nothing for the time in which it is supposed to turn the other direction.

When you run the demo program what do the motor LEDs do? Specifically, what are the M2 LEDs doing when you run the demo? Do they both turn on? Does only one light up?

Even though it sounds like you have touched up the soldering since you posted the picture, it looks like some of the pins (specifically the M2 pins) could use a little more solder. Just in case, you might try again after adding some solder and reflowing some of the pins and then posting another picture. We have seen issues like this caused by weak solder joints before.

By the way, if you are powering the Arduino through the shield, you should make sure you supply a voltage within the Arduino operating range (7V - 12V).


Here is the new soldering: https://goo.gl/photos/3aiodrjk8JCgZCuv6

While both the red and green LEDs light up on the M1 side (as it moves forwards and backwards), only the red LED on the M2 side lights up while the motor is moving, and no LEDs are on while it is not moving.

In addition, when I look at the serial monitor for the program, it always says that the current on M2 is 0, even when the motor is moving. There are legitimate numbers for M1.

I am powering the Arduino through the USB cable at the moment (without the shorting block).

Could you try running the demo without a motor connected to M2 and see what the LEDs do? Separately, could you try measuring the voltage on the current sense pin for M2?