AHRS_Orientation Yaw 180 / Roll 90

Dear all,

After lots of reading I think I’am losing my mind. I have a APM 2.5 with a 3DR uBlox GPS with Compass Kit.

Now I’ve decided that my AHRS_Orientation needs to be adjusted to;

Roll = 90 Because it’s on it’s right side facing forward.
Yaw = 180 Because the direction arrow is backwards

It seems like this is just not available in the APM planner parameters,

Is there a different way? No I cannot just change the Ardupilot on its otherside

Thank you!

dear peter , are you not confusing roll and yaw? because if you say “90 Because it’s on it’s right side facing forward” i think it’s a yaw.

If you are sure that you need Yaw=180 and Roll=90, then yes, that option doesn’t seem available.

However, option 32 Roll270Pitch180 is equivalent to the rotation you need.

Still, I think it is problematic that the list of available AHRS_Orientation options which are available do no follow the aerospace Euler angles convention:


I’ll probably raise an issue about it.

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Issue posted: https://github.com/ArduPilot/ardupilot/issues/4939

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Dear Samys13,


I think I am confused… seeying the issue description Georacer wrote down…

Thank you for your comment, I don’t see how I could confuse the 90" roll with Yaw;

When I have a plane in forward direction, I would use my ailerons, which means the plane rolls to the right, therefore - The flightcontroller(FC) is on it’s right side, where the top of the FC is facing towards the right when banked 90".

The YAW problem/requirement comes in that the FC will be mounted on it side in a Bixler 3 where the USB port should be on the top side (thats why the Roll is needed). The FC will be mounted on the right side of the bixler and therefor I need a Yaw 180. (sorry this is very confusing to do without images). (Not at home at the moment).

Still, if you think Im confused you’re more than welcome to help :slight_smile:

Dear Georacer,

Thank you, I will try the option 32, Roll270, Pitch 180, I cannot really wrap my mind around it, but it will probably be same result but over a different axes…

If I use option 32, and look in Mission Planner and I see my Rolls, pitches en compas direction the correct way, that means it is working right?

Do I need to do something with my external compass values? It’s going to be mounted in a normal way.

I think you don’t need to do anything with the external compass, if it’s mounted upright and facing forward.


Found a different user with the exact question. I cannot really use the other side if the fuselage.