One interesting thing about it is it uses the step/dir and two mode pins to set the micro-steps, from 1 to 1/256. Since that gets a little confusing, we figured a driver (https://github.com/adafruit/Adafruit_STSPIN) would be worth doing. The table was definitely annoying to decode, and higher microsteps started overflowing 16-bit variables, but now we've got it spinning happily!