imawolfking / ardupirates

Automatically exported from code.google.com/p/ardupirates
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Suggest: automated MAGCALIBRATION #17

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago
I'm not entirely confident that I completely grasp how MAGCALIBRATION works, 
but would there be a possibility that we calibrate true north via CLI or Serial 
Monitor by letting the user point the multicopter to true north, take mag 
readings and calculate the calibration programmatically ?

Original issue reported on code.google.com by kidogof...@gmail.com on 25 Jan 2011 at 9:49

GoogleCodeExporter commented 9 years ago
unlease you have a magnetometer that can point to true north.  Most only points 
to magnetic north.  I was thinking if you can walk with your Quad in a certain 
direction (straight line, because then the GPS gives you a heading) then we can 
take that GPS reading (because that is true north) as a calibration for 
Magnetometer.....

Original comment by lohnieh@gmail.com on 25 Jan 2011 at 10:39

GoogleCodeExporter commented 9 years ago
What I meant is the following:

I take a real compass (old style, iron needle and all that) and align my 
multicopter to true north using this real compass.

Now that it is aligned, I take a reading from my magnetometers (which have been 
offsetted already) and now I can calculate what my calibration value should be.

Original comment by kidogof...@gmail.com on 25 Jan 2011 at 11:19

GoogleCodeExporter commented 9 years ago
The way you are doing it is getting a magnetic north.  Compass can only give
a magnetic north.  True North is a calculation based on how far you are away
from the equator.  The further away the bigger the declination (difference
between True North and Magnetic North).  My declination is about 20degrees
which is huge because we are far South (South Africa)....  But GPS give True
North readings.

Original comment by lohnieh@gmail.com on 25 Jan 2011 at 2:39

GoogleCodeExporter commented 9 years ago
Gotcha, I'll try and pick this up in my ArduPirates configurator (yes, yes... 
more info soon enough)

Original comment by kidogof...@gmail.com on 26 Jan 2011 at 8:57