It took some work and tuning, but my own Open EVSE is online!
After connecting the Advanced Power Supply cabling it’s automatically switchting to Level 2 charging on 30A.
I made a small change to the Open EVSE code since in the EU we have 230/400V instead of 110/220V. This can be found on my Github account.
Today I already got another Roadster on visit while helping him with installing OVMS in his 2.0 Roadster Sport. It charged nicely on 30A for about 4 hours.
To get Open EVSE working with the Roadster I had to add a 2.4k resistor on top of R1 to get the resistance back to 650 ~ 700 Ohm, like mentioned in the Open EVSE issue tracker.
Below are two pictures of both Roadster charging at the newly installed EVSE.
If you have any questions, feel free to contact me!