[solved] Trigger camera via MAVROS

Ground Control Software MAVLink
1

Hello,
I use a Pixhawk with Arducopter 3.3 and I want to trigger the camera with mavros.
I try with
rosservice call /mavros/cmd/trigger_control 1 0
but it answer :
success: False
result: 3
And nothing in mavros terminal:
The link is working as when I call :
rosrun mavros mavsafety arm
In terminal:
Request failed. Check mavros logs
And in mavros terminal:
[ERROR] [1476375492.460409636]: FCU: PreArm: inconsistent compasses

Is /mavros/cmd/trigger_control supposed to work with ArduCopter or only with PX4 firmware ?
How to trigger camera via mavros ? With RC_Override ?

Thanks for your help

2

The service /mavros/cmd/trigger_control use MAV_CMD_DO_TRIGGER_CONTROL (2003), but Arducopter use MAVLink message 203, DO_DIGICAM_CONTROL.
Trying with:
rosservice call /mavros/cmd/command 1 203 0 0 0 0 0 1 0 0

success: True
result: 0
ros log [ WARN] [1476455456.543873868]: CMD: Unexpected command 203, result 3

3 mean MAV_RESULT_UNSUPPORTED : Command UNKNOWN/UNSUPPORTED
EDIT : Or it is MAV_CMD_ACK_ERR_ACCESS_DENIED = 3

But 203 is what Mission Planner use for triggering:
MainV2.comPort.doCommand(MAV_CMD.DO_DIGICAM_CONTROL, 0, 0, 0, 0, 1, 0, 0);
How to forge the same message with mavros ?
With mavproxy, “cammsg” return me the same error.

3

Hi,
I just test in copter3.4 and both mavros and mavproxy commands that you used are working. Normally, it should be supported in copter 3.3. I don’t have pixhawk to test right now . I will give a try on monday on a pixhawk with copter 3.3

4

Thank you, so it is not an arducopter problem, nor mavros or mavproxy.

I think I’m just missing something, like setting SYSID_MYGCS.
I’ve tried 1 and 255 but same error.
Maybe I’ve missed something else ?

I have updated MAVProxy with: sudo pip install -U pymavlink MAVProxy

Using Mission Planner and click on “Trigger camera Now” work. => So it is not a config problem on Pixhawk side, right ?
Using mavproxy in SITL mode it works.
:disappointed:

5

Their is a major difference between your config and sitl : you are on copter 3.3 and sitl is 3.4 . I will test monday on real pixhawk . But it is strange that is works with mission planner and not with other. I will test and get back to you ok ?

6

Hello,
I tried on two others computers and the behaviour is the same.
Probably a software version mismatch… all 3 computers where using:

  • Ubuntu 14.04
  • ROS indigo
  • Mavros from ros-indigo package (maybe that’s the problem ?)

After doing a “sudo pip install -U pymavlink MAVProxy” I don’t see the error message in mavproxy but nothing seems to work (not able to change mode for example)
Still the same error in mavros.
I will try to build mavros from source and maybe also 3.4. Is it safe to fly with it ?

EDIT following mavros/mavros/README.md at master · mavlink/mavros · GitHub I got an error:

error: pathspec ‘2016.10.10’ did not match any file(s) known to git.
In “git tag” I have a “upstream/2016.10.10”
Same error on 16.04 with Kinetics

EDIT2:
I tried on 16.04 with Kinetics:

sudo apt-get install ros-kinetic-mavros ros-kinetic-mavros-extras
roslaunch mavros apm.launch fcu_url:=/dev/ttyUSB0:57600 _gcs_url:=‘udp://:14555@localhost:14550’
$ rosservice call /mavros/cmd/command 1 203 0 0 0 0 0 1 0 0
success: True
result: 0
CMD: Unexpected command 203, result 3

(Still Arducopter 3.3.3)
Copter is not armed and arming check failed but with RC the camera trigger. With MP also.

7

Hi, just try on copter 3.3 with mavros ,and it failed… on lastest copter beta, no problem.

1 Like
8

Well done, I’ve loaded “V3.4-rc6” on-board and it works !