RC Radio RSSI and LQ data - only in tlog?

ArduCopter Copter 4.5
1

I’ve flown a test mission on a new copter and I wanted to check the RSSI and LQ values. The copter uses ELRS for the RC radio and I’m not using a telemetry radio.

Looking at the WIKI, it appears that this data is only captured in a tlog. I’m not flying with a ground control station, so I don’t have the tlog.

I don’t get into this particular area very often - so I may be way off base.

Here’s my BIN file. Is there a way to see the quality of the RC radio link? Tribble Mill Park - test mission - 2025-03-02 11-22-40.bin - Google Drive

Thanks!

2

I think there are RAD packages in the .bin file.

3

If you aren’t using a GCS you could do logging of that data right on your radio (assuming you’re using something with EdgeTX)

RAD data in the .bin has RSSI but I don’t see LQ.

4

RAD is for telemetry radios.

5

Thanks for the Oscar Liang link.

RAD is for telemetry radios - so no help.

I don’t know how much ArduPilot touches the CRLF data stream that downlinks to the transmitter - but the data I’m looking if is in there.

I’m using an older RadioMaster TX16S with OpenTX - I may be able to get a log of the telemetry - but it would sure be easier if it were in the BIN file.

I’m using Yaapu which displays the radio link data - so for now I’ll just keep an eye on it. (and make sure my failsafes are set!)

6

Almost certain this is what you’re after:

{E5CD9D81-1F3B-4CFD-955F-BEB4BBD2AF3B}

It’s in all of my .bin logs for ExpressLRS vehicles.

2 Likes
7

It’s there but I’m not sure how useful it is.

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And I know for sure the LQ was far more dramatic than that.

Edit:

This might be more useful:

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8

Thanks Yuri -

I found this in the WIKI:
https://ardupilot.org/copter/docs/common-tbs-rc.html

Looks like I neglected to set RSSI_TYPE=3. I’m not sure how I forgot this. I recall forgetting to set this on an earlier ELRS copter and got errors until I fixed it.

Many thanks!

9

Thanks @Allister

Several years back I wrote a custom chart in MavExplorer (handy tool) that charted distance against RSSI. I took a little math because I had to compute the distance from the GPS values for side to side and fore and aft distances (I forget those parameter names)

Although I always stay within VLOS, I think it’s good practice to check this kind of thing just to make sure there’s nothing weird going on.

I’m sure that post is still out there where I described how I did it.

10

There is a preset graph in MavExplorer for that now, RSSI_Distance

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Just no LQ data.

1 Like