Labroides
Captain
Flight distance : 9991457 ft
Australia
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Ice_2k Posted at 3-8 11:52
I recently took a trip to the mountains (200km from my home) and upon starting up, the drone immediately requested compass calibration. This happened within 10s of powering it so 100% it did not have gps lock yet. I don’t know how the drone “knew” something was different but it did. For reasons that are not relevant here, i couldn’t do the calibration and just flew it like that with no issues. 3 days later when i got back home, i powered it up and the calibration requirement was gone.
I don’t understand enough about the compass’ internal workings to say why this happened but the fact that the compass “feels” the different magnetic properties of the earth at different locations seems obvious. How juch this matters, I don’t know.
Also, it’s a bit weird how some people keep posting screenshots from the dji manuals when it suits them and when it doesn’t they just stick with “dji is just wrong here”. You can’t have it both ways, what dji says is either a reliable source or it isn’t. Given my unintened experiment (which was repeated twice during the last 2 months), it’s clear to me that they are correct about the location being important. I don’t see what else could explain the drone immediately sensing without gps that its location was different.
I recently took a trip to the mountains (200km from my home) and upon starting up, the drone immediately requested compass calibration. This happened within 10s of powering it so 100% it did not have gps lock yet. I don’t know how the drone “knew” something was different but it did. For reasons that are not relevant here, i couldn’t do the calibration.
That isn't a great mystery.
Your compass detected a magnetic field stronger than the earth's normal magnetic field and warned you about it,
That magnetic field interfered with your attempt to recalibrate.
The waning was poorly worded and said Magnetic Interference Move aircraft or calibrate compass.
Moving the drone away from the problem was the proper action, since recalibrating a perfectly working compass wouldn't do anything to solve the problem.
I don’t understand enough about the compass’ internal workings to say why this happened but the fact that the compass “feels” the different magnetic properties of the earth at different locations seems obvious. How juch this matters, I don’t know.
The compass "feels" any magnetic field around it.
Move a steel nail around a pocket compass to see how this works.
Also, it’s a bit weird how some people keep posting screenshots from the dji manuals when it suits them and when it doesn’t they just stick with “dji is just wrong here”. You can’t have it both ways, what dji says is either a reliable source or it isn’t.
When it comes to compass calibration, DJI has been confusing with the misleading information they have put out.
They got it right once, in the manual for the P4 pro which said: Only calibrate the compass when the DJIO Go 4 app or the status indicator prompt you to so.
All you need to know about compass calibration is clearly spelled out in this accurate and well written piece:
http://www.phantomhelp.com/tips/ ... alibration-guide.30
Given my unintened experiment (which was repeated twice during the last 2 months), it’s clear to me that they are correct about the location being important. I don’t see what else could explain the drone immediately sensing without gps that its location was different.
You have misinterpreted your "experiment".
Location makes no difference to the compass.
Your compass was reacting to being close to something steel.
I've been doing a little experiment of my own which demonstrates that location doesn't matter.
I bought a new P4 pro over three years ago.
It came from China and I have never calibrated anything on it.
It has travelled 5000 kilometres east-west and 3000 km north-south, flown over 5000 km in more than 1000 successful flights, and never asked for compass calibration.
And it still flies as reliably as it did on day one.
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