It occurs to me that if you take an Arduino program that is used with RRCI, you can use that as a standalone program to test your hardware. ASCOM and NINA can come later.
This because, the protocol is text based over serial and has human readable commands, so you can open the serial monitor and type the commands manually - open#, close# etc.
Obviously, you'll have to change the code to suit your electrical setup, but you can then do thorough testing of your hardware without the complications of the upstream software on the PC.