Telem port with FrSky output

Trying to get my FrSky Passthrough working with no luck.
i got the inverter cable and a small scope, trying to analyze the signal that’s coming out of of one of the serial ports.
when the port is configured to Mavlink, i can see data coming out (and IN because of the inverter cable that’s connected). once changing the protocol to FrSky Passthrough (Serial1_Protocol=10) nothing is coming out. both the S.Port and Tx/Rx are quiet.
@yaapu any thoughts ? does the pixhawk suppose to transmit data all the time when Telem port is set to 10 ?

What are all your related parameters set to?


Now i’m confused. Maybe bad hardware ?
I can’t flash my R161 also… (Pixhawk identifies SBUS correctly).

without a connected receiver that does the polling you will not see any traffic from the serial port with SERIAL_PROOCOL=10.
The pixhawk does not have a built in inverter so you will either need an external inverter or a receiver with an uninverted sport/fport pad.
Did you follow the wiki, it really is well done!

Hi @yaapu and Thanks for your reply.
I’ve swapped the R161 with a new R-XSR.
I’ve connected it to the Black Cube using an inverter cable (purchased from AliExpress) and it seems to be working.
I’ve flashed V2.1.0 on it with F.Port and now i’m getting telemetry for the first 1 second. (RC_in is working fine all the time).
without the inverter cable, i’me getting only RC_in and no Telemetry ay all.
(i’m connecting the F/S.Port cable to the pin noted as P in the pic attached

parameters are set as described in Connecting to FrSky Sport and FPort — Copter documentation

Any thoughts ?