One can even skip the SPC cable and just solder a diode between the TXout and Rin on the FUL-1 and use that pin as the signal pin to the receiver. I have that working with X8Rs. However, I had an additional question. How do I wire this to a Frsky XSR that doesn’t have a second wire for the s.port? I connected it without a ground (just the s.port signal wires) and that didn’t work. I tried connecting the ground wire to 2 different grounds on the flight controller and that didn’t work. Do I need to splice it into the ground wire that goes from the receiver to the SBUS connector? Will that work? Any assistance would be appreciated. Thanks.