Using Arduino for the first time.

I am attempting to use a nano with a A3967 easy driver to move a nema 16 12v stepper aprox 1/2 rotation stop. Then return to original location. I plan on using a 12v supply and want to use a relay to send a 12v signal or reference to the nano to start the stepper forward to a certain spot and stop. When the relay stops sending the signal to nano make the stepper reverse to original position. I'm making a batman wall decoration using rgb led strip lighting not on arduino with a pir circuit that changes the color of lights at that time i want the arduino to move the wings out with one color and back in with a different color. my problem is not sure how to use arduino for ref signal and ho to write programming any suggestions would be helpful.
Thanks

again arduino only runs the stepper

Did the sample stepper motor program work correctly?

You DO NOT want to send a 12 volt signal to any Arduino. Certain death!

Why not just use the relay as a push button and just ground the Arduino pin?

Paul

I have not created any arduino program still waiting to recieve my boards and still learning how to program. as for the relay its part of my pir circuit. it feeds a pc board for my leds. i can try to step the volage down but not sure how to wire it to the nano. outside of playing with the blink program i have no experience with building or using arduino. i just know that it can do what i need. still learning how.

If you must trigger the Arduino from a 12v circuit you can use two resistors as a voltage divider to reduce the signal voltage below 5v. To bring 12v down to (say) 4.3v you could use a 10k resistor and 5.6k resistor. But do make sure that the maximum voltage from the voltage divider can NEVER exceed 5v.

...R