I need to use two stepper motors to move microscope positioning knobs in the X/Y direction. The stepper motors I have are unipolar and are 6V rated (I think).

I know it's possible to drive a unipolar stepper motor via a ULN2003 using an Arduino Uno. I know I can wire it using the 2-wire or 4-wire method.

But my questions are:

Is it possible to drive 2 of them? What are the modifications I will need to make to the circuit? Will this harm my Arduino? Do I need a stepper motor shield?

2 Answers 2


No problem. Just use two ULN2003 chips, one for each stepper.

No need for a motor/stepper shield on these unipolar steppers.

It will not harm the arduino (if wired correctly).

  • 1
    Two fully independent unipolar-stepper axis will require two chips, as these have only 7 channels while unipolar steppers require four each. Dec 19, 2014 at 15:18
  • @ChrisStratton Good catch. That's what I meant to say. Bad wording on my part. Edited it.
    – Gerben
    Dec 19, 2014 at 15:27

I'd suggest to have a look at the EasyDriver stepper motor drivers developed by Brian Schmalz. They are easy to set up and do support microstepping, which might be interesting for a more fine control of the microscope.

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