I'm working on motorising my roll-off observatory roof and ultimately I would like to control it from Ekos.

I understand this would fall under Dome control but I would only need the park / unpark (i.e. Roof close / open) functionality and not the dome rotation that follows the mount.

I'm fine with the mechanics and coding on the roof controller side (probably an Arduino).

The question is: is there an existing INDI dome driver that I could use where the communication with the controller is documented? I could then write the controller firmware according to that protocol.
I have done something similar with my DIY motor focuser where I found a project with Arduino code that simulates a Moonlite focuser ("myFocuserPro" - sourceforge.net/projects/arduinofocuscontrollerpro/ ) and modified the code slightly to fit my focuser.
I have Arduino and .NET coding experience, but no experience whatsoever with coding on Linux / INDI.

And I also want to build a motorised dust cap with flat frame light source later. I would have exact same question for that project.
I have found this page on the INDI website that talks about a DIY dust cover but this is not the way I want to do it (connecting to the RaspberryPi I/O pins directly. It would have to be over USB.