You need to under stand Robin's comment about H-Bridges , dc motors and stepper motors. Do you understand WHY an H-BRIGE is not necessary for a stepper ? In order to understand this, you need to understand the difference in operation of a dc motor verses a stepper. A dc motor reverses direction by reversing polarity. A stepper motor reverses direction by energizing different coils in a specific sequence. Unlike a dc motor , a stepper motor requires power to maintain a motionless position . It must always have TWO coils energized at any given time . See the attached table for the sequence. To reverse direction , the sequence is executed in reverse order. That is the only difference in direction for a stepper. Note how the energized coils are 1 & 2, 2 & 3, 3 & 4, for CW motion and the reverse order for CCW operation. Using an H-Bridge isn't going to help you because it is designed for reversing POLARITY , whereas for a stepper , the POLARITY is ALWAYS the same. The ONLY thing that changes is the sequence. It is either moving in 1,2,3,4 order or 4,3,2,1 order. (with two windings energized at all times)
