Camera trigger using Pixfalcon


Add me as someone else looking to do this. Remapping the AUX1 and AUX2 to a spare PWM output on the Pixfalcon would be very useful. I have 8 “motor” outputs but only need 4, that leaves another 4 I could be using for aux servo’s (e.g. landing gear) and/or gimbals. I’m setting up the dev environment to see how this works now.


@LorenzMeier - Would be great if you could write code to a re-map and drive PWM Aux1->4 over to the unused M5-M8 pins for us PixFalcon users ; add a CLI command adv-param to switch these PWM to those Aux maps for Quad. So far don’t know anybody using it for Hex or Octa - Being so small it’s commonly installed in tiny 250mm Quads but we still wish to have mission function outcomes to leverage the PX4 capabilities inside :slight_smile: - thanks!


I agree that being able to selectively map motor outputs and aux outputs to the available ‘motor’ outs would be very useful for driving a gimbal and other ancillaries.


Dear Mr. Lorenz,

I understood that PixFalcon does not have the AUX to trigger a camera.

Can it be patched to achieve so or alternatively use the PicoSwitch Relay ( when using it on an Octacopter?

Thanks and regards



Is this still an active topic? I have not been able to find any suggestions or working solutions for mapping the camera trigger signal to a main pwm port. If this has been solved or is in the process, please point me in the right direction :slight_smile:

Best Regards
Johannes Friis


Did this go anywhere. I’m keen to do autocamera trigger as well


Hello! I found a solution to your issue which I recently acquired. Is quite simple actually. If you still have the problem I can help you on making any camera function with pixfalcon.



Would you be kind and explain how you went about triggering the camera with a pixfalcon?

I’m only using the Pixfalcon as a camera trigger and a data collector for the logs so for my case, i have all 8 main-out ports available, but no AUX


Hi Agdroner.
I would certainly be very interested. Please let us hear more.
Best regards
Jakob Thrane


Sure thing!
We are using two cameras:

  1. MAPIR: you just have to make a ground connection to RC channel 7 and activate the trigger function (rc7_function), set your values and there you go.
  2. Canon with CHDK: You will need a switch for a 5V output. You can that the 5V input from the PM cable directly to feed the electronic switch. Also ground the RC channel 7, set values and plug everything.
  3. Hardware Modified Camera: use an electronic switch (I haven’t done this but a friend did it with success).

You just need the signal from RC channel 7 (or any channel) to tell the trigger to do its job. You used this electronic switch.

Hope this helps on your projects.


Thanks Agdroner.
But are you actually running PX4 software on your Pixfalcon? I Cannot find the “rc7_function” in PX4, its only present in ardupilot.


Hi Guys, do you have any news about this topic? there is a way to control the gimbal also with the free output?


Hi guys, I’m also in the same problem, have a ready flying wing with a camera activated by PWM, but no AUX. Please can someone write a code which allow to set the trigger on a MAIN output?


Me too, why is this not possible?


I hope this thread is still active. As I was trying to use camera trigger via MAVlink message but it seems that Telemetry1 (only one available on pixfalcon) did not give out the message. I can intercept all other message though. So my question is: does camera trigger message only send out on Telemetry2?

If the camera tigger message were broadcast to all telemetry channels, I can then make a small microcontroller to intercept this message and make a trigger signal.


Best to use a more recent board like the Pixracer (which is a FMUv4 generation design).


@LorenzMeier, I’ve been trying to set up a PixRacer on a ZOHD-Orbit; which is similar to the Z-84. I’m using QGC v3.3.2 and PX4 v1.8.0 stack firmware. I’ve several times competed all sensors, radio calibration, etc.; but every time the Taranis transmitter connects to the D4R-II receiver, QGC reports MANUAL CONTROL LOST messages. I’ve tried both Generic and Z-84 airframe configurations, but same results.

I’m also experiencing issue #8475; which is still open.


Hi Al,

I’m thinking maybe you are going to get scolded for not starting a new post in the correct category. LOL. Having said that, check your RC IN cable. Happy 4th and God Bless America


Hi Mitchell,

I thought about that too so I did here. The MANUAL CONTROL LOST message was related to this issue with the ESP unit. Thanks, and Happy 4th!


I have same but little bit different problem. :slight_smile: Currently I am working on HITL simulator, that uses X-Plane link code, that I modified for simulator API. Is it possible to send camera PWM value from configured AUX port to HITL simulation? I am trying to understand camera_trigger.cpp to be able to allow sending signal from camera_trigger.cpp to mixer. Is this good place to modify code to achive my goal?