Hi There

Can someone explain to me what mavlink is? I can't seem to find a solid definition of what it is and how it works. Does mavlink telemetry still work to its full capability at 50hz or only in the 150hz mode (ie can it be used for long range)? Also is mavlink only available when using the full sized tx? When using certain tbs receivers? Mavlink is different than the info on the OLED screens that the bigger crossfire modules have right?

The reason is I'm thinking of upgrading from my micro tx v2 to the lite or full sized module. I'm researching into a long range fixed wing build and have ideas of setting up an antenna tracker. But in order to use an antenna tracker it has to be paired with an autopilot/fc of the same brand (ie eagle tree fc with eagle tree aat, myflydream fc with myflydream aat, etc). This is when I found out that you can use "mavlink telemetry" to provide gps chords to an antenna tracker and get it to work with say an inav flight controller. In that case I would have to consider if the full-sized module would be better over the lite because of mavlink capabilities. I will come up with more questions but for now that's it.

Thanks

I am not going to dive too deep but Mavlink is a bidirectional protocol that can be used for both RC link and telemetry back to the transmitter.

The full size Crossfire TX module can emulate Mavlink over bluetooth where as microTX was to be able to emulate Mavlink over wifi. Having said that any Crossfire RX can be wired and setup for bidirectional Mavlink. There are some limitations but lets not get into that now but the manual does show wiring diagrams etc to indicate Mavlink integration.

One thing to remember is that telemetry link is usually limited to a short distance. Which is why OSD telemetry is used by several LR pilots.

For the purposes of an antenna tracker, one concept is to embed GPS telemetry in the video link but you need additional hardware capabilities for this such as IRC EzOSD.

So it seems like Mavlink then wouldn't be a good option for long range antenna tracking.

I took a look at this IRC ezosd. Is it possible to wire this up with say a matek inav FC and have the osd from the FC but have an "underlying" gps signal from the ezosd? Basically just supplying the osd with 5v/gnd and then connecting the gps signal to the vtx? I would think the video signal from the FC (after overlaying OSD) and the signal from the ezosd would clash as they would have to be soldered to the same pad on the vtx.


//Edit: ok so actually I misunderstood. The cam/osd signal from the FC would go into the Ezosd and then from the Ezosd into the vtx. So by disabling all the osd elements of the ezosd, you get the osd elements from the FC but there is still gps telemetry in the vtx signal? Which then an IRC antenna tracker can pick up and use for tracking?

Thanks

Basically the Camera feed will be connected to the FC where OSD elements will be burned onto the images, then the video out from the FC will be connected to the EzOSD board (at this point GPS coordinates are embedded into the video feed) and then video from the EzOSD is connected to the VTX.

Another solution worth looking at is: https://www.rcgroups.com/forums/showthre...t-KISS-etc

This solution does not require additional OSD hardware and uses custom firmware to embed GPS coordinates into the video feed using the FC’s you onboard OSD chip. I am not sure how active the development of this system is and it will require custom firmware for the FC (iNav may have merged this is their firmware but I can’t track the implementation due to lack of time).

I've done some more research and it certainly is a lot to digest. But I have come up with some conclusions and options that I have:

1) iNav FC - Sentinel AAT (through iNav OSD chip)

2) iNav FC w/ Pixel OSD
- Sentinel AAT w/ minim OSD
- IRC AAT w/ EzOSD
- MFD AAT w/ Telefly tiny module
All 3 of these modules would essentially be feeding GPS data into the vtx signal where the AAT picks it up.

I like the look of the Pixel OSD so I might go down that route. Though I do wonder if pixel OSD is reliable. Do you know if it is a solid system or is it unreliable (desyncs, etc)?

Sorry I have no experience with Pixel based OSD. I have only seen a few videos of it but never experienced it first hand.