Pololu 3730 high power motor driver 36v4 with stepper motor

I am using NEMA 17 17HS1538-P4170 with the driver for one of the projects. The motor responds when I upload basicsteppingSPI code but doesn’t when I upload BasicStepping arduino code. Input voltage Vin to the motor is 12V and I am varying sd.setCurrentMilliamps36v4(1000); to sd.setCurrentMilliamps36v4(1500); in the code but no luck.

Please let me know if there are any connection missing and as per my observation motor is not energizing. Following are the list of connections of my circuit

Arduino-Mega 2560 pins-------Driver pins

  1. 2---------DIR
  2. 3---------STEP
  3. 4---------SCS
  4. 50-------SDATAO
  5. 51-------SDATAI
  6. 52-------SCLK
  7. 5V-------SLEEP & IOREF
  8. GND-------GND
  9. V5(OUT), RST, FLT-----LEFT OPEN

Looking forward to hear form you.


I am sorry to hear you’re having trouble running the BasicStepping sketch for the High-Power Stepper Motor Driver library for Arduino. Can you use different pins on your Arduino Mega 2560 for the DIR and STEP pins on the motor driver? (Please be sure to make the appropriate changes in the example code too.) Also, can you post pictures of your setup showing how everything is connected and the soldering on the back-side of the motor driver board?

- Amanda

I tried changing the pin numbers but no luck.

The solder joints on the motor driver, especially on the left-side (when looking at the bottom of the board in your first picture), do not look like they are making good contact with the board, which might be the source of the problem. Can you try touching up all the soldering and see if that helps? Adafruit has a good resource on making good soldering connections.

Looking at your connections you have pins 6, 7, and 8 on your Arduino Mega 2560 connected to pins DIR, STEP, and SCS, respectively. Can you confirm you assigned those values to the correct variables in your BasicStepping example code?

- Amanda

Thank you Amanda for your feedback.

  1. I did re-solder the the left-side joints of the stepper driver.
  2. I also changed the connections of DIR, STEP ans SCS respectively, but there was no luck.
  3. Once after I opened the serial monitor window, the stepper motor started responding.

Can you please give me some insights on this so that I can understand the driver better and use according to my requirement.

I strongly believe that such behavior is due to sd.resetSettings(); and sd.clearStatus(); functions.

Why do you think that sd.resetSettings() and sd.clearStatus() are causing your stepper motor to be unresponsive? Can you post the entire code you modified here?

- Amanda

Dear Amanda,

I hve a big problem with your POLOLU-3730. There are only two options: Enable motor means full voltage on both coils of the motor, no PWM. Or disable motor over SPI, no current on the coils of the motor. There is no manual, no support and obviously the datasheet is wrong or you send defective productrs. I haven’t bought it just for switching on and off. This can be done by a simple Mosfet. It should do PWM!!! It is very, very complicate to use your product, need many wires, but no result. Is this the quality of your products? What can I do?

Dear Amanda,

Now I have managed to run the motor, but without Step, the full voltage is applied to the coils. No PWM. How could I reduce the current while stopping the motor? The TORQUE register can’t change anything… .

Hello, SuperUser.

This is not how to talk to people, both from a human interaction perspective and from a technical communication perspective. You are welcome to adjust your attitude, read something like our what to write advice, and try again.

- Ben


Dear Ben,
Sorry, that you have no solution for my simple problem. This means, you don’t want to help me. Sorry for asking you.