I am going to describe by observation a different way.
I am using Arduino with this stepper motor:
With the Easy Stepper Driver Board:
This motor is normally 200 steps/rev.
I know I am in microstepping (1/8 step) mode, the default, because when I send EXACTLY 1600 steps, I observe EXACTLY one complete revolution.
However, when I increase the delay between steps to "delay(500)", I observe much inaccuracy from microstep to microstep. Sometimes, at some microsteps, the motor doesn't move at all. Other steps, it moves more. It seems like, at some at some microsteps, it is "catching up".
The is NO mechanical load on the motor.
Is microstepping this way just VERY inaccurate?
I wanted to be able connect a button and get one exactly microstep per button press, but it looks like that will just not be possible. Am I right?
It looks like I will get 1.8 degrees ever 8 button presses. But the individual microsteps may or may not be proportional due to inaccuracy of each microstep.
Thanks,
Mark