SOLVED: Revolution with NEO-6M Gps and Compass error
« on: May 06, 2018, 12:47:44 pm »
Hello,

New on this forum, but reading a lot from it.
I have a problem with my own build quadcopter, which has a revolution controller board, combined with a U-blox neo-6m gps and compass. I have more that 8 satellites for gps. GPS is connected over main port, and the compass over the flexiport using I2C. Calibration procedures completed for all four steps. When i select the dials, they go all over the place, with the quadcopter standing outside, away from all kind of interruptions next to me. The selected compass is the neo-6m compass, because the internal mag will always give 100% error.

Has anybody an idea what could be the problem?
Searched already a lot, but cant seem to find a solution.
Video attached
« Last Edit: May 09, 2018, 06:52:21 am by TwanGraus »

f5soh

  • *****
  • 4446
    • LibrePilot
Re: Revolution with NEO-6M Gps and Compass error
« Reply #1 on: May 06, 2018, 01:16:03 pm »
Hi, welcome.
There is no compass error in video, just a warning happening from time to time.

Quote
because the internal mag will always give 100% error.
Since the "AuxMagOnly" is selected, the onBoard mag is ignored for navigation: this is the recommended setting.
For the onBoard mag 100% error you should remove the Liposaver/buzzer (very close from board) and redo Mag calibration.

Re: Revolution with NEO-6M Gps and Compass error
« Reply #2 on: May 06, 2018, 01:35:14 pm »
Hello,

Thanks for your quick reply.
But in the video, it isnt correct that the compass orientation and artificial horizon go all over the place, with the quad standing still right?
The lipo buzzer isnt connected, but error still occurs. But guess this doesnt matter because in dont use internal mag.


regards

Re: Revolution with NEO-6M Gps and Compass error
« Reply #3 on: May 06, 2018, 05:02:46 pm »
Compass is true 3D so it gives some information about which way is up.  When mag and accels do not agree which way is up, the code gets confused and the attitude state goes all over the place.  It can't be flown (at least in self leveling modes) like that.

Is the mag built into the GPS?  If so, and if the GPS is mounted normally (with arrow on GPS pointing forward) then the GPS/mag  orientation as set in Configuration->Attitude->Magnetometer->Aux.Mag.Orientation must be set to (0,180,0) or (180,0,180).  These are actually the same orientations.

Lipo buzzer has real magnets in it and changes the 3D compass data from where it should be.

If you still have a problem after fixing these two things, post your config file with your next question.  It might help.
« Last Edit: May 06, 2018, 05:31:12 pm by TheOtherCliff »

Re: Revolution with NEO-6M Gps and Compass error
« Reply #4 on: May 07, 2018, 07:51:02 pm »
Hi,

Thanks for your help, really appreciating it!
The removal of the lipo buzzer works miracles on the aux mag, what a difference!
Unfortuannaly, the artificial horizon and compass keep going like hell, without the Quad moving. I also eddited the orientation like you said. Ill add the .UAV file as attachment to this post, hope you guys can help!

regards

Re: Revolution with NEO-6M Gps and Compass error
« Reply #5 on: May 07, 2018, 08:03:55 pm »
In Attitude estimation algoritm when set to complemetary+mag+GPSoutdoor, the compass and artificial horizon stay steady, but arent the same as the real thing.

Re: Revolution with NEO-6M Gps and Compass error
« Reply #6 on: May 07, 2018, 08:05:53 pm »
Is the mag built into the GPS?  Is the GPS is mounted normally (with arrow on GPS pointing forward)?

If mag is not part of the GPS then you will need to determine the orientation.

If removing the lipo alarm helped then you certainly need to redo mag calibration after moving/removing alarm, but get the mag orientation correct first.

Re: Revolution with NEO-6M Gps and Compass error
« Reply #7 on: May 07, 2018, 08:07:51 pm »
The mag is built in to the gps, and the arrow on the gps is facing the front of the quad.
I will redo the calibrations and let you know the results.

Re: Revolution with NEO-6M Gps and Compass error
« Reply #8 on: May 07, 2018, 08:09:45 pm »
In Attitude estimation algoritm when set to complemetary+mag+GPSoutdoor, the compass and artificial horizon stay steady, but arent the same as the real thing.

Then it may be that the FC orientation is not set correctly.  That would also cause this.  Or if you have made other settings changes to try to fix something...

When holding the quad in Complementary(+...) and you tilt it leftward, the artificial horizon tilts RIGHTward.  When you tilt it forward, you see more brown (ground) on the AH.

Re: Revolution with NEO-6M Gps and Compass error
« Reply #9 on: May 07, 2018, 09:18:03 pm »
Hello,

Edited the orientation to roll at 180 degrees, and the artificial horizon works fine now. I can even fly with complemetary+mag+GPSoutdoor, but INS13 i will try tomorrow. Thanks a lot so far!
Aparently, the removal of the lipo buzzer and recalibration had major impacts!

regards

Re: Revolution with NEO-6M Gps and Compass error
« Reply #10 on: May 07, 2018, 10:03:53 pm »
You didn't say which orientation you changed, FC or GPS(/mag).

Roll,Pitch,Yaw  The GPS must be 0,180,0 or 180,0,180
You said you changed it to 180,0,0 which is wrong.   :'(

Re: Revolution with NEO-6M Gps and Compass error
« Reply #11 on: May 08, 2018, 05:16:47 pm »
Youre right,

The aux mag orientation needs to be 180,0,180. And the board orientation 0,0,0.
Thanks for the help. This topic can be closed now.
I think the removal of the lipo buzzer and then the recalibrating was the trick

thanks a lot!

Re: Revolution with NEO-6M Gps and Compass error
« Reply #12 on: May 08, 2018, 07:50:51 pm »
You can edit your first post and change the title/subject to add the word SOLVED: or similar to the beginning of the title.

If it needed mag orientation number change, then that is without a doubt one thing that can cause crazy PFD.  Set it back to 0,0,0 and watch it go crazy again.  :)