Enabling serial ports in KConfig - Telem3 not working

We had previously been using a Taranis controller with the FRSky module and with this we were able to use the SBus port on the Pixhawk Cube Orange carrier board (Pixhawk2) to send telemetry back to the Taranis controller by setting TEL_FRSKY_CONFIG to TELEM3.

This was originally on PX4 v1.12.1.
However, now that we’ve updated to v1.13.1 we are unable to get it to work.
We have enabled the Telem3 port to ttyS4 shown below (as it had been by default in v1.12.1) and this allowed us to set TEL_FRSKY_CONFIG to TELEM3 again, however it doesn’t seem to work. Are there additional steps to enabling another serial port than just modifying the KConfig?
Have the ports been redefined elsewhere in the software?

Any help would be greatly appreciated!


So just setting the param TEL_FRSKY_CONFIG to Telem3 does not work?

Which port is that on the Cube Orange?

Sorry for the late reply @JulianOes, completely forgot this post was open!

Previously, we’d done some digging whilst on v1.12.1 and discovered that the CONS pins equate to Serial5 which can be used with Telem3 (which was previously mapped to ttyS4), so we’d been using this to send telemetry back through FRSky. In v1.13, with the new KConfig structure, Telem3 is disabled by default.
The issue with v1.13.1 stemmed from the update for the newer ADS-B integrated carrier board which, by default, opens a mavlink connection on ttyS4 (see /boards/cubepilot/cubeorange/init/rc.board_mavlink). This obviously conflicts when enabling Telem3 on ttyS4.

So to fix this for us, we just disabled this default connection (very simple commenting out in this PR) and enabled Telem3 in KConfig as you would expect. Now, setting TEL_FRSKY_CONFIG to Telem3 works properly.

Let me know if you have any other questions; I’ve probably not explained it that well!

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