MultiWii

I am trying to get my compass reading correctly. I have the readings going in the proper direction per the sensor position directions. The problem is when I turn the quad upside down. The N/S axis does not flip like it should when its flipped on its pitch axis. If I flip the quad on the roll axis, the compass readings do flip. Is this a problem? I'm preparing for GPS, I need to make sure the compass is working properly.

I think you don't want to fly upside down with MAG on.

Understood. It does show that the Mag is not always showing where north is, which could cause problems with navigation.

It does show that the Mag is not always showing where north is, which could cause problems with navigation.

If the Mag sensor is not accurate then there is a chance that the "3D" calibration was not performed correctly or the sensor is too close to metal objects or magnets.

BTW, you should also check the mag sensor's accuracy *under all throttle settings* to ensure that magnetic fields from the nearby high current wiring does not affect it.

- Thomas

Working with multiwii is is always a good idea to have a standard arduino (like UNO etc.) around to directly check those sensors.

You can find sketches for the sensors in the web.

MAG -> https://www.loveelectronics.co.uk/Tutor ... no-library

Then you know, it is not the sensor but the software.

BR

Did you assign the right axis definition in config.h?
Does it behave like descirbed in the FAQ? -> http://www.multiwii.com/faq

How should be the sensor axis directions

TILT the MULTI to the RIGHT (left side up):

MAG_ROLL, ACC_ROLL and GYRO_ROLL goes up
MAG_Z and ACC_Z goes down

TILT the MULTI forward (tail up):

MAG_PITCH, ACC_PITCH and GYRO_PITCH goes up
MAG_Z and ACC_Z goes down

Rotating the copter clockwise (YAW):

GYRO_YAW goes up

The copter stays level:

MAG_Z is positive ; ACC_Z is positive

greetz
noctaro

Yes, the sensors move according to the FAQ. It just seems that it should always point north, even when its inverted, and it does not currently. I did find that the roll and pitch axis do NOT correspond to the silkscreening on the sensor bob. Silkscreen says y is roll, but I had to tell software x is roll to get proper values in GUI.

hmmm....got weird with the axis definition of mag since the beginning......
i know anywhere around here was a threat about an alternative compass calibration....wasnt it EOSBandi who talked about?
i will have a look if i can find it.

edit:
here we go ->
viewtopic.php?f=8&t=1068&p=7329&hilit=compass+calibration#p7329

maybe this will help you out?
...just guessing...as i did not prepare for gps right now

greetz

Noc