Very interested in this Rowland.
I'm currently trying to fix a Losmandy Gemini for David (Brundah1) and I'm also just about finished a very nice PIC stepper motor focuser control (with ASCOM control, temp control and focuser wheel re-positioning control) by
Dave Trewren.
More here.
Just about finished this project...have some way to go on the Gemini...but am always open to "new projects"!
But If I could get lets say....-2C (exif)....with PWM feedback temp control wow! Now I'd buy that!
Brendan