Analog thermal camera with Herelink


I just got my hands on the Herelink system a couple of months back and I made a drone using it and the drone is working absolutely fine. I have tested both the radio and the Solex telemetry of Herelink and it’s working correctly.

However, when it came to the camera, it got me some problems in using the Analog camera with Herelink. Actually, I wanted to use a thermal camera with an analog output with herelink and after trying everything it still failed.

Here are the things I tried:

  1. Firstly, I converted the analog output to an HDMI one using an “AV to HDMI converter” and also tested the HDMI video on an external monitor with an HDMI port. It was working fine on the monitor on both 720p and 1080p resolutions which are changeable by a switch on the converter.
    (The converter was similar to this:

  2. After this I used a small “HDMI to micro HDMI board” and plugged-in the HDMI video to the herelink air unit and tried. Got no video on the receiver.

  3. After searching a bit on this forum, I tried powering on the camera after the air unit has powered on, and vice versa, and still got no image. Tried 2-3 times, but still the same result.

  4. Also tried connecting to both the HDMI ports on the air unit, one at a time, and switching from Solex, but still failed.

  5. Also tried with both 720p and 1080p resolutions from the converter. Still failed. Also tried with QGC, but still failed.

  6. After this, I tried reflashing both the air unit and ground station to the latest firmware and retried points 3, 4, and 5. Still no image. Tried reflashing 3 more times and retried. Still no image.

  7. At this point I was clueless about what to do. So I decided to go to a Sony store and try their camera with inbuilt micro HDMI output, just to be sure that my herelink was not broken. As soon as I plugged in their HDMI output to the air unit, I started receiving live video on Solex in less than 2 seconds, without any settings or so. Just out of the box!
    The Sony camera which I tested was “Sony RX 100 II”

Now I think that it has something to do with the HDMI protocol.

Whenever I tried to use my camera with converter, I always got this message on Solex that “Unable to stream video: DESCRIBE request failed with code 404”

Can anyone please give me more information on the HDMI protocol which the herelink wants? Or any converter which is proven to be working with herelink? Or any kind of information regarding the HDMI converter IC or anything.


Which camera are you using? Maybe there is a better option than a av2hdmi converter?!

Yes to discuss that “better option” only, I have posted this query here.
I am using a custom-made thermal camera from an OEM.

Some of the analog to HDMI converters will just convert the incoming analog signal to HDMI 480i, not upscale it to HDMI 720p or 1080p. HereLink supports 720P 30fps & 1080P 30/60fps. Try putting the output from your analog to HDMI converter into a TV and see what it outputs.


There are certain cameras which work with Herelink and certain not, that depends upon the manufacturer, and the same with Herelink different. Check this list out it may helps you research more.

Also try if the resolution of the convertor is same what is set in the herelink receiver.

Hope it helps

Hi Curtis,

I tried putting the converted HDMI signal into an external computer monitor and it was working fine on the screen. Also, when I switched the resolution from 720p to 1080p and vice versa, the monitor was also displaying the input resolution at the time of switching i.e. “720p” or “1080p”.

I have attached pictures of the same for reference.


720p 1080p

Hi Sumit,

Thanks for the reply.
Yes I had already checked out that list before, but the problem is that I am using a custom made camera from an OEM and using any company’s mass manufactured consumer camera. That is why I am confused as what to try next as I can see the HDMI output working properly on an external computer monitor.


If I had to work with an analog video signal I would try to get a converter to csi and use a raspberry zero to send the image towards the HereLink.

Hi Tobias,

Thank you for the suggestion.

Actually as I mentioned, I am able to get the HDMI video on my computer’s screen using the converter, but not able to get it working with the herelink. So I am clueless as to whether this method would also work or not. Have you tried that method with herelink before?


@philip @Alvin @MadRC
Do you guys have any idea regarding this issue? Could you please suggest me something.

Hi @Harkhka,

There are examples online where a Raspberry has been used together with HereLink. Using this method offers great flexibility.

If you cannot find a analog video to csi converter you could still use a usb equivalent together with a Raspberry Pi Zero.

You’re method does not work because the air unit is picky regarding the HDMI signal it does except.


Can you verify whether the video source is H.264 MP4?

Frame rate is the key. It need to be be 30fps at 1080p.

Hi Tobias,
Thank you for the information. I will keep that in mind and try that whenever I can.
Thanks for the help. Appreciate it.

Hi Alvin,
Yes, I confirmed from the manufacturer that the analog video output is H.264 only.

Hi Ian,
I cannot say about the fps of the input analog video, but can an HDMI converter also increase the frame rate of the video, in addition to increasing the pixel count?