I’m looking to drive a very small stepper, it’s a 4 wire bipolar with a max voltage of 1.25-7.5v, and an average current of only 22ma. I’d like to be able to micro step it. Any suggestions on a driver or a way to accomplish this? It almost seems feasible to drive it straight off the arduino itself, (normally a bad idea…) if I did that how would one go about micro stepping it?
You could drive that motor directly from the Arduino pins, but, as with any H-bridge, you will need diodes to power and ground on each motor lead to protect the output pins from voltage transients.
Microstepping requires very precise, coordinated control of the winding currents.
I actually set up a circuit with diodes to do exactly that the arduino is not capable of doing the coordinated control of current is it? I was actually able to get it to do more or less what I needed to do at what I thought was an acceptable rate and accuracy, however what I did find I was having trouble with is the motor would go to its position then end up bouncing a few steps every couple of seconds. Which seems to be a different problem all together.
Google driving arduino x27.168
This is a similar stepper that is like yours used for automotive guages.
Check this link, I think it has a library to control and initialise the stepper.