Gimbal interprets cardinal directions as relative azimuth

Hi all, long time military UAS guy here, but newbie to ArduPilot.

Bottom Line Up Front (BLUF): Setting “Point Camera Here” in MP to cardinal north results in gimbal pointing to relative 12 o’clock, regardless of actual aircraft cardinal direction orientation.

After years of flying military drones and a Comp Sci degree, I’m trying my hand at a custom drone during our COVID downtime.


  • Frame: Hexacopter X
  • FC: Cube Orange
  • GNSS: Here2 (via UAVCAN)
  • Gimbal: Tarot T-3D V
  • Firmware: Multiple versions of ArduCopter attempted (Aug-Sep 2020 stable releases)

Gimbal is controlled via Aux 1 & 2 (pan & tilt), and generally responds as expected to MP “Point Camera Here” commands, except… it appears to interpret grid 360* (due north) on the map as “point to 12 o’clock” relative to the aircraft. The compass’s reported direction is correct in MP, as is general GPS location. 3D Fix OK, compass angle OK; gimbal motors/calibration OK (except for the direction it points). Problem replicated on multiple reboots in various aircraft orientations.

If the aircraft is oriented due north throughout the mission, this would be OK; however, as soon as the aircraft points off due north, then the gimbal pan angle mistakes absolute direction for a relative azimuth. Example: when the aircraft is pointed due East, and “Point Camera Here” is given to the east (090* absolute, but 12 o’clock relative), then the gimbal slews to the right (3 o’clock relative, but 180* absolute, aka due south). Defeats the purpose of an ROI command, which has yielded plenty of in-flight footage of my landing gear.

FWIW, the “Reset Position” command in the “Payload Control” window resets the gimbal to 0/0/0 (straight ahead and level), and the Pan/Tilt sliders work as expected. I think the problem lies entirely with interpreting absolute azimuths as relative angles during ROI commands.

Anything helps. Thanks!

this is because of a bug introduced 1,2 years ago or so (has_pan_control). ArduPilot unfortunately hasn’t understood that the Solo gimbal isn’t a normal gimbal.So you need to wait for them to (1) accept that there is a bug and (2) correct it. May not happen soon. For the moment you can disconnect the rc control for the pan axis, the missions then should work. :slight_smile:

github pull requests are welcome. I volunteer to review it.

this is frankly not my experience at all. You’ll figure it out.
I just wanted to respond to the users so they don’t think they’re doing something wrong and waste their time and nerves :slight_smile:

#sadface, bummer that it’s a SW glitch, and I can’t immediately tweak one parameter to fix the problem. But relieved that it’s not completely user error.

Thank you for the link to the other thread, I’ll be following this and on the lookout for updates.

In the meantime, I suppose I’ll just disable the Pan axis, and let the aircraft handle ROI’s with yaw and gimbal tilt (I hope).

There was a commit to ArduCopter master today that maybe addressed this issue. Can you try the latest master from today?

Thanks for pointing this out - I’ve been trying to work out how to get this working on a Pixhawk with Tarot 3D-III for ages and without luck. I had suspected a SW bug, but was more convinced it was user error. Hopefully the dev team will be able to address it soon.