Having already got my OpenLRS set up to send Mavlink data back from my plane (using the gitsly OpenLRS branch), the next step was to get Mavlink data displayed on my Taranis.
The Taranis need inverted levels to serial pin in the module bay so I build an inverter from the schematic here.
I saw this topic a while back: MAVLink data displayed on OpenTX (9X/9XR/etc) radio screen via Open... and assumed this would also work on Taranis. No such luck! There is no EXT=MAVLINK option for Taranis in the configurator.
However I managed to get the OpenTX build environment set up on Ubuntu following the instructions here without too many difficulties. Then is was a matter of redirecting the telemetry bytes into the existing mavlink code, and displaying the Mavlink settings and telemetry screens rather than the Frsky ones. I was quite surprised when it all worked however! The Mavlink serial is also available from the serial connector on the OpenLRS module so that can be connected to a PC or Android device.
In the original 9X Mavlink firmware it was not possible to select which telemetry protocol to use except by reflashing. I need a mixture of S.Port and Mavlink telemetry depending on which plane I'm flying so that didn't suit me too well. I added an option in the model menu telemetry options to use Mavlink rather than S.Port or Dbus, so each model can have it's Mavlink or Frsky telemetry received and displayed :) .
I also thought it would be useful to have the radio read the flight modes as they are receiver over Mavlink, this wasn't too hard to incorporate either. I created sound files for each Arduplane mode and added code to play them on receipt of a new mode.
Something else I would like do is to copy the Mavlink data into the normal Frsky variables so that they can be used in the normal way, i.e. read out, used in Lua scripts and for vario sounds etc.. It's on the to-do list.
Hopefully this will be useful to some people out there, I will post the code after I get a chance to clean it up slightly as it is a bit of a hack! For now the binary and sound files are here (they need to be in the SOUNDS/en folder):