Herelink "waiting for video" when connected to MP via UDPCI

Hello everyone,

This problem is pretty particular to my setup as I use a custom companion computer, although it may have a common solution since it’s related to Herelink and MP.
Please excuse me if I put this topic in the wrong section, it relates to multiple topics so it was a tough choice…
Any help will be appreciated :slight_smile:

Usual behavior :
I am using a Cube Orange along with a Herelink and a Firefly Split camera to obtain a video stream.
Firefly cam sends its video stream to Herelink’s airunit via HDMI, Herelink sends the video stream to its RC (with QGroundControl), on which I am able to see the video.
If I connect my Herelink RC to MP via UDPCI or UDP, the params load on MP and I can still see the video on my Herelink RC.
Unusual behavior
When using my custom companion computer on Telem2, I lose the video signal totally. Herelink’s QGC stays in “Waiting for video”. This only happens when I connect to MP using UDPCI.

Companion computer
I am currently developping a companion computer for a specific application. This companion computer communicates with my autopilot via Telem2, using mavlink 2.
On boot, my companion computer sends a lot of TIMESYNC requests in order to get an optimal message travel time. Right before doing so, it sets all Mavlink messages rates to 0 (except Heartbeat etc) to “lighten” the mavlink data stream.
The video stream stops between the moments every rate is set to 0 and the moment I request a lot of timesyncs.

This right here lead me to think I was setting the wrong mavlink messages to 0 and potentially asking the autopilot to stop the video stream.
However I did not think my companion computer would be able to interact with my herelink airunit’s camera on HDMI via the autopilot’s Telem2…
Moreover, my camera is only connected to my Herelink Airunit via HDMI… It shouldn’t have any MavID of its own to send mavlink requests to.

What’s strange :
This happens ONLY when my Herelink is connectected to MissionPlanner via UDPCI.
This does not happen when my Herelink is connected to MP via UDP, nor when the Herelink is not connected to MP. Video stream stays on QGC.

Moreover, when connecting to MP using UDPCI, the device list shows a MavID 42-Camera next to my 14-QUADROTOR
This MavID is not there when I connect to MP via UDP.
I searched through all Herelink’s, MP, and Arducopter params, I never found any reference to this MavID 42 for the camera.

Graphical summary
And there you go : my attempt to graphically summarize the problem

If you are still reading, thank you so much, I’m looking forward to solving this problem with you :smiley:

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  1. How did you link MP with Herelink RC ? Was it thro’a PC
  2. Can you share the the pin out diagram between companion computer and CUBE Orange ?
    Is the telemetry port configured as I2c

thanks in advance

Hi, thanks for your reply !

  1. Mission Planner runs on a Win10 on my laptop, which is connected to the same portable WiFi Hotspot as my Herelink RC. I then connect MP to Herelink RC using UDPCI, choosing port 14552 and entering the Herelink’s IP address.
  2. I do not quite get the question… My companion computer is connecter to the Cube Orange via Telem2 port, which is a serial port, with a JST-JST cable between both hardware, and the Serial2 configured as such :
    As I mentioned before, my companion computer works fine, I get the data I want, the mavlink stream is (as much as possible) stable… The only surprise is the Herelink’s behavior regarding the camera …
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Sorry for the delay.
You mention in your diagram 2.4ghz . But as far as i know , Herelink only connects at 5GHz. Can you please advice how you managed with 2.4Ghz !
Can you send me a sample program to see how I can send commands to RasPi using Herelink RC

Hi ,

As you can see in the documentation, the Herelink’s frequency band (between RC and Airunit) is 2.4HGHz. I have custom 2.4 GHz antennas installed on my drone especially for the Herelink.
As for the Wifi connection, my RC is conntected to a 2.4GHz Wifi Hotspot.
I did not configure anything further than this.

In order to send commands to a RasPi using the Herelink RC, you should be able to send a Mavlink command from the RC to the Airunit, and then receive it on a Serial port of your Raspi and use the Mavlink library to decode it on your Raspi. I am not sure wether you can directly read the telem directly out of the Herelink Airunit , or if you really need to pass through a Cube.
You can check this guide for a Autopilot to Raspi communication : Communicating with Raspberry Pi via MAVLink — Dev documentation

About my post, I guess you do not have any solution to offer, so maybe you could post you own topic to get help from the community :slight_smile:

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thank you , mate !! … To add further here, may be the topic " Herelink Ethernet " may help your issue …Please check the herelink forum with this title .

You’re welcome and thank you for the link

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This seems to have been resolved by newer versions of Arducopter, since this problem does not occur anymore after I updated to Copter 4.2 and above.