piotr/openipc-builder
1
0
Fork 0
Code Issues 2 Pull Requests 1 Actions Packages Projects Releases 2 Wiki Activity

Forward FC flight telemetry to Ground Station over a robust WFB stream #4

New Issue
Open
opened 2026-11-03 22:39:15 +01:00 by hermes · 0 comments
hermes commented 2026-11-03 22:39:15 +01:00
Collaborator
Copy Link
Copy Source

Goal

Provide live FC telemetry to Ground Station independently of the ExpressLRS downlink and independently of the video decoder.

Why

ExpressLRS control uplink can remain usable after handset telemetry is lost, especially with a small receiver whose telemetry transmitter has no PA. Ground Station needs battery/GPS/flight state even in that asymmetric-link region.

Data source

Reuse the existing persistent FC MSP UART owner (msposd). Extract a bounded structured snapshot from MSP data already available to the VTX: at minimum arm state, battery voltage/current/consumed capacity/remaining where available, GPS fix/satellites/latitude/longitude/altitude/ground speed/home data where available, attitude/flight mode, and sequence/timestamp.

Transport

Send this as a separate low-rate WFB downlink stream, not embedded in RTP/video frames. Use authenticated/encrypted WFB stream mechanics and a robust independent MCS/FEC profile. WFB-NG supports separate stream IDs and independent stream settings; select and document one reserved project stream ID without colliding with video, mavlink or tunnel ranges.

Constraints

  • preserve exactly one persistent msposd owner of FC UART;
  • no keys, arbitrary commands or credentials in telemetry payload;
  • fixed/versioned schema, bounded packet size and update rate;
  • video failure/absence must not stop telemetry stream;
  • telemetry publishing must not delay MSP DisplayPort or pilot video;
  • source absence/staleness is explicit.

Acceptance

With video decode stopped but WFB radio active, Orange Pi still receives fresh FC battery/GPS/arm snapshots. Under induced video loss/congestion, telemetry remains usable longer than the high-bitrate video stream. Hardware/flight validation is performed by Piotr.

## Goal Provide live FC telemetry to Ground Station independently of the ExpressLRS downlink and independently of the video decoder. ## Why ExpressLRS control uplink can remain usable after handset telemetry is lost, especially with a small receiver whose telemetry transmitter has no PA. Ground Station needs battery/GPS/flight state even in that asymmetric-link region. ## Data source Reuse the existing persistent FC MSP UART owner (`msposd`). Extract a bounded structured snapshot from MSP data already available to the VTX: at minimum arm state, battery voltage/current/consumed capacity/remaining where available, GPS fix/satellites/latitude/longitude/altitude/ground speed/home data where available, attitude/flight mode, and sequence/timestamp. ## Transport Send this as a separate low-rate WFB downlink stream, not embedded in RTP/video frames. Use authenticated/encrypted WFB stream mechanics and a robust independent MCS/FEC profile. WFB-NG supports separate stream IDs and independent stream settings; select and document one reserved project stream ID without colliding with video, mavlink or tunnel ranges. ## Constraints - preserve exactly one persistent `msposd` owner of FC UART; - no keys, arbitrary commands or credentials in telemetry payload; - fixed/versioned schema, bounded packet size and update rate; - video failure/absence must not stop telemetry stream; - telemetry publishing must not delay MSP DisplayPort or pilot video; - source absence/staleness is explicit. ## Acceptance With video decode stopped but WFB radio active, Orange Pi still receives fresh FC battery/GPS/arm snapshots. Under induced video loss/congestion, telemetry remains usable longer than the high-bitrate video stream. Hardware/flight validation is performed by Piotr.
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
No items
No labels
Milestone
No items
No Milestone
Projects
Clear projects
No projects
Assignees
Clear assignees
grzesiu hermes piotr (Piotr Sarna)
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: piotr/openipc-builder#4