A friend of mine is building a stepper driver, writing his own program for a PIC.
He needs to nkow about step and direction. I would not mind knowing either...
What exactly does it 'tell' the motor? Can somebody give a breakdown of what these pulses do, is it change direction or what? I will give more specific questions in a few hours when I see him again
It doesn't tell the motor anything, it's aimed to the controller. The controller has to change the polarity on the motor's windings to make it move.
Assuming a unipolar drive, a sequence like this is needed to move it on one direction:
or for halfstepping:
For turning the other way the sequence must be reversed. So whenever the controller receives a step signal while the direction pin is high it should move the motor in the next step of the sequence, if the direction is low to the previous.
What the controller will do from there depends on the type of motor it has to control (unipolar/ bipolar) and the step type (full/ half etc).