Stepper motor

As you'll know, micro stepping is using continuously variable phase currents instead of simple on-off switching. The phase currents are mostly applied according to a sine and cosine function. The micro stepper interfaces I know, e.g. from allegromicro.com, have specific analog hardware for the current control. You can try, if your interface can work with PWM control. But without a current control loop, the current and respective position programming won't be very exact. In addition, it should be mentioned, that not all stepper motor types are equally suited for micro stepping. Motors with a large step size can be expected to show considerable angle non-linearity.