This is a nice object...
MakeBlock stepper motor driver
...but is seems a bit expensive. I like it because it drives 4 wire stepper motors using only two wires of the Arduino (corresponding to Direction and Step).
But are there any alternatives?
Pololu sells both A4988 and DRV8825 based stepper driver boards and A4988 drivers are widely available on EBay. Most specialized stepper drivers just require step and direction inputs.
Make sure that you choose a driver that can comfortably supply the current required by your motor.
Robin2:
Pololu sells both A4988...
Thanks for your reply. I can't seem to see this expilicitly in the PDF data sheet, but...
Q1) I suppose that MS1 MS2 and MS3 are the step size selection and can be tied high or low as I like?
Q2) Also it seems to be designed for 4 wire stepper motors. Is that right?
Yes and yes. You'll find the slightly cooler running DRV8825 modules on eBay too.
To get started with either A4988 or DRV8825 you might find this UPDATE: Current adjustment for motor drivers (DRV8825 / A4988) - Motors, Mechanics, Power and CNC - Arduino Forum information helpful.
rpt007:
To get started with either A4988 or DRV8825 you might...information helpful.
Many thanks for that link.
You are welcome.
If not yet done, have a look at reply#1, where @Robin2 posted useful links to get your stepper move after having set the current limit.