LibrePilot Forum

Development => GCS General => Topic started by: Anonator on November 23, 2018, 01:00:26 am

Title: Magnetometer fails on calibration
Post by: Anonator on November 23, 2018, 01:00:26 am
Using next version I get error calibrating magnetometer with a Revo onboard mag. Tried with aux mag (DJI GPS/Compass)... also failed.  What can cause an error to calibrate?
Title: Re: Magnetometer fails on calibration
Post by: TheOtherCliff on November 23, 2018, 05:12:26 am
Magnets close to the sensors.  There are magnets in LiPo alarms, in the speakers (speakers not piezo).

A lot of metal in the area.

A lot of AC power close by.

Really should be done outdoors.

Once calibrations starts, it constantly gathers data, not just when you press the button 6 times.  You must not set it on the ground between presses.  You must not set it on a car between presses.

Maybe waiting too long between presses and generally taking too long.  I am not sure If this is actually a problem.

Incorrect motions or motions too fast.  Motions are not critical and very hard to make it too fast to pass.  Hard to make this a problem at all.

Are you following the instructions or are you trying to do a different mag dance?
Title: Re: Magnetometer fails on calibration
Post by: Anonator on February 06, 2019, 07:54:50 am
Thanks Cliff,

Revo mag calibrated fine.  New problem with calibrating AugMag, a DJI GPS/MAG, on Omnibus F4 Pro.  There is no onboard mag so I set to OnlyAux and DJI protocol but mag calibration repeatedly fails.  Note GPS works fine and I can see valid mag data in scope.  Mr_W code works fine otherwise...  Perhaps code exits when no valid builtin mag found before writing the AuxMag calibration data?  Looking in system I see the Omni mag data is never changed from default.
Title: Re: Magnetometer fails on calibration
Post by: TheOtherCliff on February 06, 2019, 08:19:30 am
I have some Omnibus F4 Pro too, but I have never used a GPS/mag with them.

I can imagine two problems right off.  Mag cal is a GUI function and eg. CC3D does not allow mag cal.  It may need to be more fully enabled in GCS to work.  Also, before Omni, all FCs that allow an aux mag also have an on board mag.  This may be another area where the Omni is special.  I recall the GCS code and it does a sequence of steps to both onboard and aux.  Onboard would obviously fail.

Luckily, the aux mag doesn't care what it is connected to.  You could calibrate it with a Revo, etc. (temporarily mounted in that model) and just copy the Revo aux mag calibration data to the Omni.
Title: Re: Magnetometer fails on calibration
Post by: Anonator on February 06, 2019, 08:22:38 am
Good suggestion Cliff.  :D