[vtx] Add support for VTX control via Tramp and SmartAudio protocols

[niklaut]

Solved Problem

• VTX protocols and robust round-robin scheduler
  • Tramp protocol
  • SmartAudio v1, v2, v2.1 protocol
• Control of band, channel, frequency, power, pit mode.
  • CRSF MSP message parser for setting
  • RC input via aux map table
  • Parameters via Mavlink or QGC/AMC
• RC aux map table and VTX table support saved/restored from file
• Receiving VTX table and RX AUX map table via uORB/DDS
• Sending VTX settings and state via uORB/DDS
• CLI interface similar to betaflight

Depends on #25693.

Changelog Entry

For release notes:

Feature: Add VTX support with Tramp and SmartAudio protocols

Alternatives

The uORB messages are quite large, but I didn't come up with anything better.

Also proper module documentation is currently missing, it's unlikely I'll have time for this in the next two months tho.

Test coverage

• Testing in hardware with various Tramp and SA VTXes

[github-actions]

🔎 FLASH Analysis

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Updated: 2025-10-13T09:58:48

[PetervdPerk-NXP]

Cool work, any chance to consolidate MSP VTX (HDZero, DJI etc) as well?
We do have MSP VTX support inside the OSD driver albeit by CLI,

PX4-Autopilot/src/drivers/osd/msp_osd/msp_osd.cpp

Line 669 in 0fe8738

int MspOsd::set_channel(char *new_channel)

[niklaut]

Cool work, any chance to consolidate MSP VTX (HDZero, DJI etc) as well?

Eventually yes, but not in this PR. I see that the VTX table config is duplicated, but that can be shared later internally without impacting any public interfaces. Otherwise the OSD driver probably also wants to listen to the vtx message and relay that information later.

[jsm09a]

Does this address issue #24903 by any chance ?

[niklaut]

Does this address issue #24903 by any chance ?

Edit: No, not at all. Kinda.

I've implemented support for the CRSF MSP message MSP_SET_VTX_CONFIG (89=0x59) that allows setting band/channel/frequency/power/pitmode via CRSF.
But the rest of the protocol, ie. using MSP to write the VTX table is not implemented.