Hi,
started looking into focuser rotators recently, but couldn't afford the pretty pricey options that are the commercial items.
Came upon this site:
http://www.scopefocus.info/home/rotator
Which has plans for a really low cost DIY build. Includes Arduino code and Ascom drivers. Originally designed for a Tak CAA, but concept easily adapted to other installations.
Have found the owner of the site really helpful with questions and suggestions.
Have all the bits on order now (under a hundred dollars)
Hope it's useful to others..
cheers
Gary