How to troubleshoot missing CAM messages

Yesterday on a test photo survey mission, about a third of the hot-shoe CAM messages were missing. All of the TRIG messages (camera shutter commands) were present - about 850 images.

On previous missions of up to 1400 images, none of the CAM messages were missed.

Can someone please offer some suggestions on how to troubleshoot why these CAM messages might have been missed?

Hello, did you solve that trouble? i have similar issue.

  1. Check the camera hot shoe for looseness.

  2. you can take a few pictures and I’ll see if there are any problems with your camera, flight control GPS antenna and PPK wiring.

  3. you can line up the location of the missing POS information, at the beginning or end or middle of the route, and see if you can find some patterns.

I’m sorry I didn’t reply before this. For some reason, I didn’t see your comment until this morning.

I have solved the problem - but I’m not exactly sure how.

I’m using a FoxTech Map-02 camera. I’m using the hot-shoe wire provided on this camera.

I found that this required a 2K resistor to prevent a problem. This is all explained in this article I wrote: Technical Article – Foxtech Map-02 Camera and ArduPilot Integration | Copter Cam Tech

Since having this problem, I’ve remounted the camera on a new quad-copter. The wiring is new. For some reason I no longer have this problem. So my best guess is that I had faulty wiring that wasn’t keeping a good connection.

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Thank you for responding.

It appears that the problem was in my faulty wiring. Since this post, I’ve installed the FoxTech Map-02 on a different quad-copter. The copter has new wiring in the same configuration as noted on the article I wrote about using this camera. Technical Article – Foxtech Map-02 Camera and ArduPilot Integration | Copter Cam Tech

The camera now works properly. So my best guess is that I had something wrong in the wiring - and it’s now working properly on the new copter.

As info - when CAM messages are missing, it is possible to geotag with the TRIG message - which are all present.

The meaning of the CAM messages changes if you’re using hot-shoe sensing or not. If you’re not using the hot-shoe input, the CAM messages record every time the autopilot commands the camera shutter.

If you’re using hot-shoe sensing, the CAM messages record when the hot-shoe signal occurs - which is when the camera shutter is triggered. Also - a TRIG message is recorded - which records when the autopilot commands the camera shutter. This makes the TRIG messages when using the hot-shoe the same as CAM messages when not using the hot-shoe.

The Mission Planner geotag utility allows using either CAM or TRIG messages. So if the CAM messages are lost, the TRIG messages can still be used for geotagging - even if it’s a little less accurate.

Hello Joseph. Thank you for your response.
Ultimately, the root cause of the malfunction in my FC was found elsewhere.
I am using CUAV’s Nora product, and it turns out that the GPIO pin numbering set by CUAV differs from that mentioned in the Ardupilot wiki. I am attaching a link for your reference, although I’m not sure if it will be helpful to you.
Thank you for the active involvement in Ardupilot. I look forward to your continued support.

Thank you for your kind message.

I resolved my problem some time ago. But I appreciate your follow up.

Thank you!