Two drv8825 with same control pinout

Hello everybody, I’m so sorry for my bad english, I write from Italy.
I have a problem with 2 drv8825 in parallel with the same pinout in arduino.
the circuit is:
2 drv8825 (in parallel);
2 stepper motor sh2141-5541 (sanymotion 14mm motor)
1 LM1085 (12 volt LDO)
1 arduino board
1 electorlitic capacitor of 220 micro farad on supply

I need to drive the 2 motor with the same pinout, when only one motor is connected, I don’t have any problem, but when all 2 motor is connected they don’t move do only noise.
I try a lot of solution and the only who work is move the trimmer of each drv8825, now the current limit is set:
1 motor: 0.180 Volt
2 motor: 0.1 Volt
Why it’s happen? is it normal?
thanks
Gianni

Hello, Gianni.

I am sorry you are having trouble getting your DRV8825 drivers to work. Can you tell me more about your system? What are you using for power (e.g. what is supplying power to your LM1085)? In particular, how much current can it provide at the voltage it is outputting in your system? Can you post pictures that clearly show your connections?

It sounds like the behavior you noticed occurred before you set the current limit to the values you mentioned. If that is true, what were the current limits of the drivers at the time you observed the behavior of your system?

By the way, since it sounds like you are controlling a single stepper motor from each of your DRV8825, your current limits should be set for the rated coil current of your stepper motors, which looks like 300mA. (This equates to a VREF of 0.150V.)

-Jon

about our power I use a OWON ODP3032 power supply with programmed 2A in output.


thanks
giannidsg

It looks like you are using a DRV8825 carrier that we do not make, so it is beyond the scope of our technical support to help you troubleshoot it. Also, since that carrier could be configured differently, the VREF voltages I recommended that you set before might not be valid.

If you want to try with a genuine Pololu driver, you can find them on our web site or get them from our distributors. If you have the same issues with one of our boards, I would be happy to help you continue troubleshooting.

-Jon