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Old Jul 27, 2012, 10:33 PM
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Naza GPS - When adjusted for magnetic declination does it break the compass?

The Naza GPS comes with the course lock feature which I assume means the red arrow on the GPS means that is forward (don't know how the quad will know which way is forward otherwise?).

To stop the toilet bowl effect you are meant to turn the GPS around 20 degrees EAST where I am. Now that means the arrow will point away from the front of the craft.

I am noticing that heading lock seems to follow the arrow so if you leave the quad on the ground and it flashes green three times indicating a heading lock at startup, it will fly off to the right instead of straight ahead. Is anyone else noticing this?

Do DJI need to implement something in the control panel allowing you to say how many degrees you have turned the compass? That way it can compensate and fly straight on course again. Or am I completely wrong and the Naza controller itself is what sets straight ahead?
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Old Nov 25, 2012, 03:22 PM
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New Zealand, Auckland
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Im having the same issue with the toilet bowl effect, i also find that course lock stops working mid flight and i have to switch on and off again for it to come back on, have not found a solution yet, fully agree with you about implementing something to compensate to fly straight.
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Old Mar 31, 2013, 07:32 PM
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I'm having the same problem. I turned the compass anticlockwise for 12 degrees W magnetic declination; I have no problem with toilet bowl effect, but my quad doesn't fly straight ahead any more. I'd rather have TBE and will probably undo the magnetic declination adjustment.
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Old Apr 01, 2013, 01:24 AM
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United States, CO, Lakewood
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It wont break the compass Silly.

To be serious, the only thing I could think of to ask is did you guys re-calibrate the compass after turning it for declination? It should be re-calibrated after changing anything. They say even battery size. However I haven't seen a diff with this.

Also, when calibrating during the second phase, make sure the nose/front of the craft is pointed DOWN.

Also could be there is too much declination dialed in?
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Old Apr 01, 2013, 03:24 PM
ehx
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Northern Minnesota
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Some myths die hard .. or should that be some just won't die?

You don't manually adjust for magnetic declination because that's done automatically by DJI.

Here's a reference: http://www.rcgroups.com/forums/showp...ostcount=15039

Where did this myth come from? My guess is someone following the DIYdrone's APM development saw them requiring a magnetic declination lookup and just assumed it had to be done for the Naza. DIYdrones were in an early stage of code development and pressed for enough memory so they hadn't spent the few KB or so of memory space needed for a decent magnetic variation lookup table. They might have fixed this by now as they move to better hardware.

So unless DJI are lying about something really easy to do, don't bother with magnetic declination adjustments. You still may need to rotate your compass/GPS because a multirotor is a very noisy environment and a rotation can give you a better average fit to the noise .. and the lookup table isn't perfect.

As for calibrating the compass all that is important is that two 360 degree rotations, roughly orthogonal to each other, are done. Which way the nose is pointing doesn't matter.
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Old Apr 01, 2013, 03:40 PM
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Quote:
Originally Posted by ehx View Post
Some myths die hard .. or should that be some just won't die?

You don't manually adjust for magnetic declination because that's done automatically by DJI.

Here's a reference: http://www.rcgroups.com/forums/showp...ostcount=15039

...

As for calibrating the compass all that is important is that two 360 degree rotations, roughly orthogonal to each other, are done. Which way the nose is pointing doesn't matter.
Awesome - thanks ehx for the definitive information and the history on these two issues - I'll be undoing my magnetic declination fix tonight.
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Old Apr 07, 2013, 06:45 PM
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Quote:
Originally Posted by PepsiCola View Post
Awesome - thanks ehx for the definitive information and the history on these two issues - I'll be undoing my magnetic declination fix tonight.
FWIW, I'm not sure DJI has got their magnetic declination fix right. I undid my fix and pointed the GPS directly towards the front of my quad as per the original instructions, and I immediately started getting bad toilet-bowl effect in GPS Attitude mode.
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