fix(mavlink): update TransponderReport flag bitmask

[anilkir]

Solved Problem

TransponderReport.msg is missing MAVLink's SIMULATED, VERTICAL_VELOCITY_VALID, BARO_VALID, and SOURCE_UAT flags entirely (mavlink msg definition). The PX4_ADSB_FLAGS_RETRANSLATE bit (256) also collides with MAVLink's ADSB_FLAGS_BARO_VALID bit at the same value.

Solution

• Moved PX4_ADSB_FLAGS_RETRANSLATE to bit 512 (unused by MAVLink's ADSB_FLAGS enum), resolving the collision
• Added the missing flags with correct bit values.
• Forwarded the new flags in both directions: (uORB → MAVLink) and (MAVLink → uORB).

Changelog Entry

For release notes:

Fix TransponderReport ADS-B flag bitmask to match MAVLink ADSB_FLAGS.

Alternatives

Test coverage

Context

Related links, screenshot before/after, video

[github-actions]

🔎 FLASH Analysis

px4_fmu-v5x [Total VM Diff: 136 byte (0.01 %)]

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  +0.0%    +136  +0.0%    +136    .text
     +20%     +72   +20%     +72    MavlinkReceiver::handle_message_adsb_vehicle()
     +15%     +64   +15%     +64    MavlinkStreamADSBVehicle::send()
  +0.0%     +65  [ = ]       0    .debug_abbrev
  +0.0%    +335  [ = ]       0    .debug_info
  +0.0%    +136  [ = ]       0    .debug_line
     +33%      +1  [ = ]       0    [Unmapped]
    +0.0%    +135  [ = ]       0    [section .debug_line]
  -0.0%     -10  [ = ]       0    .debug_loclists
  -0.0%      -2  [ = ]       0    .debug_rnglists
  +0.0%    +244  [ = ]       0    .debug_str
  -1.6%    -136  [ = ]       0    [Unmapped]
  +0.0%    +768  +0.0%    +136    TOTAL

px4_fmu-v6x [Total VM Diff: 144 byte (0.01 %)]

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  +0.0%    +144  +0.0%    +144    .text
     +20%     +72   +20%     +72    MavlinkReceiver::handle_message_adsb_vehicle()
     +15%     +64   +15%     +64    MavlinkStreamADSBVehicle::send()
    +0.0%      +8  +0.0%      +8    [section .text]
  +0.0%     +65  [ = ]       0    .debug_abbrev
  +0.0%    +335  [ = ]       0    .debug_info
  +0.0%    +128  [ = ]       0    .debug_line
    [DEL]      -7  [ = ]       0    [Unmapped]
    +0.0%    +135  [ = ]       0    [section .debug_line]
  +0.0%     +12  [ = ]       0    .debug_loclists
  +0.0%    +244  [ = ]       0    .debug_str
  -2.7%    -144  [ = ]       0    [Unmapped]
  +0.0%    +784  +0.0%    +144    TOTAL

Updated: 2026-07-13T02:40:42

[MaEtUgR]

We could make it the last bit (32768) for now to not change value until there's a conflict with the last bit in MAVLink.

[MaEtUgR]

The last bit is used in MAVLink 🤯 Someone else had the same broken strategy 👀
https://github.com/mavlink/mavlink/blob/f9cb1f9e482977446c3dd953a16368d4834c6aa5/message_definitions/v1.0/common.xml#L3665

Should we make it a separate field to avoid future conflicts or is that overengineered? Let me check 👀

[anilkir]

Separate field works for me as it avoids any future conflicts with the MAVLink enum. Let me know your final recommendation