FrSky telemetry: document available and encoded values

The FrSky telemetry wiki page should state what values are being sent over the telemetry link, and how they are encoded.

I had to look at the code to figure this out (at least it’s open source!), and correllate my Taranis SD card logs with the pixhawk logs. The list below may not be fully complete:

Legend: : <FRSKY_ID_…>: purpose according to comments

[li] T1: TEMP1: send control_mode as Temperature 1 (TEMP1)[/li]
[li] T2: TEMP2: send number of gps satellite and gps status eg: 73 means 7 satellite and 3d lock[/li]
[li] FUEL: FUEL: send battery remaining[/li]
[li] Vfas: VFAS: send battery voltage[/li]
[li] CURR?: CURRENT: send current consumptiom[/li]
[li] Hdg: GPS_COURS_BP: send heading in degree based on AHRS and not GPS[/li]
[li] GPS lat/long: is transmitted normally[/li]
[li] Spd: GPS_SPEED_BP/AP: gps speed[/li]
[li] Alt: FRSKY_ID_BARO_ALT_BP/AP: barometer altitude[/li]
[li] GAlt: FRSKY_ID_GPS_ALT_BP/AP: gps altitude[/li][/ul]

Other available values:
[li] RSSI[/li]
[li] Batt, time: transmitter data[/li]
[li] CONS: consumption, maybe mAh used?[/li]
[li] SWR? what is this?[/li]
[li] A1: receiver voltage, a bit useless since it’s always in the 4-5V region.[/li][/ul]

[li] GPS date&time: these were logged as some fixed date&time in the year 2000 on my Taranis SD card, will need to check if it’s a logging issue or a telemetry issue[/li]
[li] AccelX,Y,Z[/li]
[li] CELLS[/li]
[li] RPM[/li]
[li] Air speed: I don’t have the airspeed sensor[/li]
[li] Vertical speed: [/li][/ul]

Knowing the above, you can now play sound files whenever the mode changes on the quad (as an alternative option to playing sounds when you flip the switch, as suggested on this page - I’m using their soundpack for this):

L1 a=x T1 0° --- --- --- L2 a=x T1 1° --- --- --- etc
and then special functions to play sound files:

SF6 L1 Play Track APM-Sta 1x SF7 L2 Play Track APM-Acro 1x etc.

I believe this to be the list of flight mode ID to name mappings. Note that there are two discontinuities (8 and 12 are missing) and that some of the modes are deprecated. I haven’t yet figured out how to extract the GPS sat#/lock type from TEMP2; I think it should be fairly straightforward with a integer division by 10 and modulo operation, I’d try the Custom Switches menu I’ve seen mentioned on some websites, but I don’t have that in the firmware version that my Taranis came flashed with.

As an alternative to using the stock telemetry on the Taranis, it might be worth looking into using some Lua scripts to decode and display the telemetry data (similarly to what this guy did)

Thanks Michiel,

This information is very useful - I have added it to the wiki here:

I have opened a github issue here: and asked the driver author if we can have help populating the missing information.

I’ll close this issue now and we can continue discussion in #98. Thanks again!