Quote Originally Posted by Jumper View Post
Why not attach a sensor with encoder from an old PC mouse on the end of the rotating axis. Then you can count how many pulses and position your screen within mm from where it should be.
You might even have a pin on your pic to a hardware counter and then it will more or less count by itself.
I thought about that too...but, if that count goes off by one this time, one the next time, and so on, one of those times, the motor is gonna drive too far, burn out, the screen is going to fall off, whatever. Still need some sort of end of travel sensor to reset the counter to zero (or 100 or whatever) once in awhile to keep things straight.