control unipolar stepper motor

The L297 has several inputs that can be generated by a PC/104 stack or other controller. This circuit allows you to control each step, in full-step mode. Meaning: You can tell it to move one step in either direction (of course you can make it move fast and it will continuously rotate). The two inputs are a direction and a pulse. In the next section you will find a program to control this using xPC.