Dual mc33926 driver Demo does not run correctly

First, I am new to Arduino and motor drivers. I just received a box of goodies and I am trying to get them to play together. I ran the “Blink” example on my Arduino Uno and it seems to be working fine. I then uploaded the MC33926 Demo and it doesn’t seem to do anything. The Arduino power LED is on and the MC33926 blue Vin LED is on, but the motor LEDs (green and red forward and back) do not turn on and off. Needless to say, the motors do not run either. The MC33926 shield is powered by an 8.4-volt (7-cell) NiMH battery pack and the Arduino Uno is plugged in to USB. The jumper between the shield and the Arduino Uno is off. I have tried running the Demo with the shield installed on the Arduino and separated with the shield on a breadboard. Still no results. I have also tried with and without the motors connected. Still no results. The shield looks pristine on both sides, so I don’t believe anything is blown. Also, I have triple checked the connections and everything seems to be connected properly in each scenario tested. Any ideas what the problem might be?

Thanks in advance,

Hello, Trey.

Are you using the unmodified demo code from our MC33926 library? Could you post close-up pictures showing both sides of the board and some pictures of your whole setup including all of your connections?



Yes, I am using the unmodified code from the library. It compiled and loaded fine onto the Arduino. I saw the Tx and Rx LEDs lighting up during the load. I have the shield installed on top of the Arduino and I have the driver battery going to the two middle power connections on the driver. I have leads coming off the other 4 terminals for the two motors, but I do not have anything connected to them at the moment. The two motors I would like to drive are Pololu 34:1 Metal Gearmotor 25Dx52L mm with 48 CPR Encoder (low power). I will post pictures as soon as I can.


I got it to work. I still don’t know what the issue was, but I am assuming an intermittent connection somewhere between the Arduino and motor driver.