(Embedded below.) He first goes over the fundamentals of a stepper motor in a practical, hands-on approach, and also shows us how to ring out the connections if the pinout is unknown. Next he ...

Driving a stepper ... with an Arduino here on Hackaday. The rationale behind this is not often explained. [Andreas] connects a common low-cost 28BYJ-48 geared stepper motor with a ULN2003 ...