I recently fried the stepper driver on M2 on my smoothieboard. Can you folks recommend suitable external drivers which are equivalent to the ones on the board? Namely, something that supports 1/16 steps on NEMA 17 at 1.5A and 3.7v power? I'm a newbie on this and not trying to use a driver that is way overkill for other than the basics. Thanks!
You could use a stepstick, though that's a bit annoying to wire.
Or you could use something like this : http://fr.aliexpress.com/item/Best-stepper-motor-driver-THB6128-28-42-stepper-motor-driver-2A-128-segment-single-axis-stepper/32264431075.html?spm=2114.06010108.3.10.KE18SB&ws_ab_test=searchweb201556_0,searchweb201602_2_10017_10034_10021_507_10022_10020_10009_10008_10018_10019,searchweb201603_1&btsid=cce97e30-393f-426c-9ae3-56b22bf6766d
You may run into problems with voltage on a stepstick. My motors are 2.8V/phase and the DRV8825 driver simply wont turn on with them connected. However, the A4988 driver (the one on the Smoothieboard) works with them just fine.