Compass heading does not match vehicle direction with nonstandard mounting

Hey guys I have something that may not be an issue but I am just checking because I have another issue and want to be sure this isn’t related. I have a rover with an APM 2.8 mounted pointing left (yaw 270) to save space. The external compass is mounted with the arrow facing the same direction. After compass calibration the heading on mission planner points in the direction of the compass and not the direction the vehicle is pointed. I tried auto missions and they seem to work just fine. Is this normal, or do I have to change the compass orientation as well? I understood the compass orientation references off the FC mounting, so I should have to make no changes in MP if it faces the same direction as the APM.
Thanks.

@thetacowarrior,
From the ArduRover Wiki:
"This article assumes that you’re using the most common configuration — a Pixhawk, PX4 or APM2.6 board with the compass mounted with the arrow facing toward the front of the vehicle and in the same direction as the arrow on the autopilot. If you’re using a different configuration see Advanced Compass Setup."
Regards,
TCIII AVD

Thanks, I checked advanced compass, everything is set according to the wiki, APM pointed left so autopilot configured as “yaw 270”, external compass also pointed left so no yaw changes according to wiki as compass orientation is relative to the FC mounting. It is set “roll 180” but that is due to the GPS unit I have. The car works pretty well on auto missions and RTL (my other issue is with steering mode not seeming to want to work). My concern is that with everything set as mentioned and compass calibrated, Mission planner indicates the heading in the direction of the APM, like it isn’t compensating for my settings. So if I aim the car north with a compass the compass heading indicates west. If I run a mission the GPS track points the correct way but the heading always points 90 degrees left of that. Is there a bug in Mission Planner or is there another issue? Some setting I missed?
Thanks.

@thetacowarrior,
I have asked our ArduRover resident Developer to take a look at your issue.
Regards,
TCIII AVD

1 Like

Ray did you resolve this issue? It looks like your setup is correct to me. If you could attach a single log file driving whilst you have the problem I can have a look.

Thanks, Grant.

No I have not resolved it, I am trying to find a log of me driving it but coming up short, and the weather has been bad since you responded, it is supposed to be nice this weekend I’ll try to get out and run it.

Ok sorry for the delay, the weather didn’t clear this weekend but I found a log of me running some missions where you can see the issue. You can see at about the 55-60% mark where the heading doesn’t match the direction the rover is going, but it runs the mission just fine.
Thanks for looking into it.
-Ray

Here’s the log:
https://1drv.ms/u/s!Anr_LKcUMz1N5GUY-z2JhEHgZr7b

The link to that tlog isn’t working for me - says its not available. Can you provide another link?

Thanks, Grant.