I am interested in learning more about your system. Could you provide a link?
I don't have it all documented, because it was never my intention to distribute it. However, I will give you a link to what I have.
I have an Exploradome, which I initially automated with the Foster control system. I was not happy with it, and replaced the controllers with my own Arduino-based controller. I kept most of the hardware, but I replaced the rotation drive motor, which was a big DC motor, with a stepper motor, driving the original gear.
The shutter consists of two doors, which need to be sequenced properly. Instead of using a wireless link to a fancy electronic controller in the dome, I built a brainless sequencer using relays, diodes, and the door limit switches. It is powered through the original battery-charging contacts, with positive voltage opening the doors and negative voltage closing them. This limits shutter operation to the home position, but that is not a big hardship.
The Arduino controls both the shutters and the rotation. It includes an autonomous emergency close function, that is triggered by rain, or power failure (I have battery backup), or by a loss of communication with the PC. I wrote an ASCOM driver for it, so it will work with any standard software.
The Arduino code is at: https://www.dropbox....e v2.0.zip?dl=0
The ASCOM driver is at: https://www.dropbox....ver v1.zip?dl=0