GPIO Time based Camera Trigger not working in QGC mission

Hi folks, I can not get the GPIO camera trigger to operate in the time based mode when running a mission in QGC. I checked previous trigger issues listed here, most seem to be from 2017,18 but could not find any related. Anybody else having this problem?

Very simple to setup/reproduce. Setup Camera for time based, on command and GPIO output. Set up the trig_ parameters for time, interval, active high, etc. Leave TRIG_PINS at default 56.
Running PX4 on Pixracer
Aux1-4 motors
Aux 5,6 camera trigger

Planned a short mission with Camera trigger in Mission Start, also tried a Start image capture command, put the camera trigger command in a waypoint and tried every other combination of commands and settings, but can’t get a trigger. Camera trigger test works, but after running a mission it sometimes gets locked out and we need to reboot. Time based, always on, works, but we can’t have the camera continuously shooting pictures. Also, when we change mode to distance based, along with associated parameters, it works flawlessly.

It’s only time time based, on command that will NOT work.

Any help would be appreciated,

Hi moonmotor…

What you describe has been my experience exactly. Did you ever get the camera to trigger using a flight plan command in mission mode?


stan, we were never able to get this to work and determined it was yet another shortcoming of MAVSDK. There were several issues. It’s been a while so I don’t remember all of them off the top of my head. We were simply trying to turn a relay on/off, but the only available function was the camera trigger so we were trying to limp along with that. Seems like turning a relay on/off is such a basic function that it should be implemented in MAVSDK, but it isn’t (or wasn’t). Another bug was that after the aircraft landed, the camera would start triggering again. This was a bug we could never work around.
Our solution was to move over to Dronekit. It has more functionality and fewer bugs. Wasted a lot of time with MAVSDK. It’s not all it’s cracked up to be.
I wish I had a better answer for you. Good luck!

Hi again, Moonmotor

Thanks for your reply. I have been watching the development team’s progress on github. There is a lot of work being done to enable Set Servo and Set Actuator during mission mode in PX4. If it is released soon, that would work for me. If not, I may have to follow you to Dronekit.