I have a CUAV pixhack V5 and i’m not sure which port to connect the spektrum satellite to. There is no DSM, just a RC input but i’d assume thats for PPM and S.BUS. I’ve tried connecting my satellite to the RC IN port but the problem is that it’s 5v and the satellite takes 3.3V and I still have no signal while powering it from an external 3.3V source.
3.3V is the minimum the satellite receiver will operate at. 4.8-5.2 volts is the recommended minimum voltage if you have a stable BEC. 5.5 volts is recommended if the BEC powering the system is not stable and droops under load from servos.
The PPM/SBus/DSM is on the RCIN and is auto-detected once the receiver is bound to the Tx. Spectrum likes to play games with their modulation schemes and with the Pixhack V3’s DX9 and above were not supported. Not sure if that is the case with the V5 - never tested it because I don’t have a DX9 radio (and wouldn’t use one even if I had it).