Shot in the dark here, I've searched and tried some things I've found but I'm just lost as to how to get this to work. All I'd like to do is setup a PIR sensor so that it activates a short back and forth cycle of the stepper motor. Any wiring and code info would be awesome. Trying to help my son out with his science fair project. Thanks!
Connect the PIR sensor to an input pin. Write a simple sketch to read the state of the PIR input and write it to the built-in LED. That will let you see how the PIR reacts to motion.
Get a stepper motor and stepper driver. Use the examples from the Stepper library to learn how to control the stepper.
Then you can create a sketch that does something with the stepper when the input from the PIR does something.
also look up the AccelStepper library