Stepper Driver Question

Hey, I’m a FOC newbie and just came across your library and it looks great. Was thinking to use it to make a stepper motor into a servo as cheaply as possible with NEMA 17 + encoder + driver. Was looking around at drivers and came across this DRV8801 breakout which looked interesting. It has built in current sense and probably would get less hot than the older L298N if you use a couple of them with small stepper and keep it under 1A. I know current sense is there to more accurately determine the magnetic field. If I went for a driver without current sense, is it going to make a noticeable difference at 12V?

Hey, and welcome to SimpleFOC!

I don’t know that much about the steppers, but I think that your plan could work. You’d be using “half” of each driver, and need 2 of them for 2-PWM control of the stepper.

it is used to do true torque control, i.e. to control the actual motor current, rather than controlling the voltage as a proxy for the current.

But you can do closed-loop control in voltage, velocity or angle mode without needing any current sensing as long as you have a angle sensor, and this will realise most of the benefits of FOC control - you will have better torque, more quiet operation and significantly reduced power consumption (and hence, less heat too).

I think you’ll probably be happy. It’s definately the way to start in any case, and you can always get back to current control and more expensive drivers at a later point when you know exactly why you would need it…

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