Internal Compass error

I have constant compass errors on the dropix internal compass. After several calibrations the compass values are still red.

First question - what should be set as orientation (AHRS_ORIENTATION) for the dropix board?

To be able to fly i have disabled the internal compass and just use the external one from the
Ublox NEO-M8N GPS + HMC5983 compass module.
This worked quite well but still EKF compass errors at every flight.
I guess it’s to the crazy configuration since i’m draining nearly 160A current at 100% throttle.
Any ideas on how to improve the compass issue?

Some pictures of the setup




Thank you, Gerald

Try to remove the Dropix from the power module to decrease the pertubations.
Let me know

Hi Jerome,
due to the construction of the frame body i can mount the Dropix on top of the PDB only. All the standoff’s are Nylon and i have connected the shielding plate between the Dropix and PDB to GND (made some scratches into the board on one side and soldered a wire to GND on the PDB). Also the CFK frame is connected to GND to reduce electromagnetic interferences.

Can you try to put longer standoff between GPS and Dropix please?
Just to see if it’s the problem.

i increased the lenght of the standoffs already from 10 to 15mm and that helped for the external compass on the GPS board.
I think the interference issue on the internal compass i cannot solve due to the frame design.
I will try to improve the shielding below the dropix FC further or simply keep the internal kompass being swithed off.

Thank you!

ok let me know. Good luck!

Thank you. I will let you know my findings.

No progress made on my side so far… have build 3 other race copters in the meantime that are flying well (the ones at the left side)

I was flying the Octo-Monster at an event up to 123km/h but have started a rebuilding activity recently. New motors, new PDB and relocation of GPS within the frame to saveguard GPS signal beeing ok when flying with ~75° pitch forward. I hope i can solve the magnetical interference with some of the modifications i have in mind e.g. Coax cable (self made) between PDB and ESC.

Nice. Keep the good work!