Hardware mounting in small plane

Hi all thanks for great work you all have done
anyway i was going to testing of 4.0 betea on BF3.2 Omnibus F4 V2.1Flight Controller in a
mini skywalker this is the onlyway i can mount the controller i am trying to get
the AHRS_ORIENTATION right and have fail to get it right

this what i have set

AHRS_CUSTOM_PIT,-90

AHRS_CUSTOM_ROLL,-90

AHRS_CUSTOM_YAW,-90

set AHRS_ORIENTATION to 35.
custom rotations are in radians really, so you’d need custom pitch and roll set to -1,5708 to get the same result, plus AHRS_ORIENTATION set to 100 (= custom).

https://github.com/ArduPilot/ardupilot/pull/12323 for reference

ok thanks for all good now

ok last issue i am having is arming

chq mag field so i did its 112.9911 ?
i though up 500 was ok

i personally am a big fan of keeping things safe and simple, so i’m most likely the worst option for advice on traditional fixed wing compass issues. i’d say: don’t use one unless required by airframe design and / or you’re sufficiently familiar with setup and maintenance so that it will add actual benefit and not just increase complexity.

that being said, maybe double check setup steps with special attention to internal / external settings as well as calibration procedures: http://ardupilot.org/plane/docs/common-compass-setup-advanced.html

aditionally, inflight compass learning imho has added loads of setup convenience and reliability: Testers needed for in-flight compass learning

if you’re 110% positive you’ve set it up correctly but the error persists, on an airframe with limited options for separation magentic interference might be an issue, depending on component placement. check if moving the mag away from drivetrain components / wiring helps.