Compass not calibrated message after every reboot

hello everyone
i’m getting compass not calibrated message on ground station after every reboot since i updated to 3.6.11
what should i do with this problem ?
config :
pixhawk 2.4.6 with AC3.6.11
Ublox M8N GPS (OLD version)

i disabled internal compass and using external compass only


The compass-not-calibrated message will come up if AP has detected that the attached compasses have changed (ie. a compass was added or removed) since the compass calibration was done.

It’s a guess but perhaps the compass isn’t being reliably detected. I’ve seen another similar case and it was resolved by slowing down ArduPilot’s boot-up time to give the sensor more time to initialise (i.e. the compass was slow to startup). This was done by increasing BRD_BOOT_DELAY to “6” (seconds).

thank you @rmackay9
i will try and share result

i cant find BRD_BOOT_DELAY in full parameter list

@hosein_gh, I’m sorry, you’re right, it’s not included in Copter-3.6. It’s new for Copter-4.0.

Copter-4.0.0 is actually quite close to going live. I wonder if you’d be happy to test with the Copter-4.0.0-rc3 beta that will go out later today to see if that resolves the problem?