New P3 advanced compass issue and few related questions
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jarmow
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Finland
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Hello. I just recently bought me a Phantom 3 advanced and since it was recommended I upgraded all firmwares before my first flight. The issue I'm having is that calibrating the compass fails every time. Closest metal things are 10 meters away at least, depending on the place I'm at. (I think the manual mentioned 1,5 meters should be ok) There is a TV / mobile link tower some 500 meters away though. Controller is also several meters away, less than 10 though. (Phone I'm using is sony xperia Z5 premium which isn't really supported but seems to work just fine. Tried with ipad mini2 but the video feed lagged too much)
I do the calibration procedure as instructed but then there will be a big warning saying that Compass error, Exit P-GPS mode etc in status window. Controller does say safe to fly on the top though. (and iirc green lights flicker on the rear) However if I then shut down the copter and turn it on again it won't say anything about compass errors. (same if I just start flying without trying to calibrate) If I fly it, it will work just fine most of the time but at some point it will start to drift (rotation+wind obviously) a bit and will give out the same error and drop out of gps mode. It's not a problem as I can fly copters in atti mode too as long as the compass issue won't mess it up. (having working video feed does help, though) So far these in flight errors have been less than 10 seconds and if I leave the switch to P it will usually return to that mode shortly.


So what I'm wondering now is that:

A: How far from metal things and / or tv etc transmitters should I really be? (I'll go to some in the middle of nowhere area next to try calibrating again) Can things like one button on my pants mess it up? (I've tried it with metal free clothing though, same thing)

B: If the compass goes to crap can I still fly normally if I switch to atti mode manually? I've understood yes, but after checking some videos on youtube I'm not sure. (or do some people just try to fix similar issues by using return to home instead of switching to A mode? (and thus having the copter go to random directions because compass is messed)

C: If this happens should I just switch to A mode and land or is it safe to keep it on P mode? Can that cause the flyaways where the copter just hits full throttle and flies somewhere until battery dies or are those some other issues?

D: If I hit return home (or lose connection) and the compass error hits while it is returning what happens? Does it stop and wait or run off into cliffside somewhere far, far away?

E: Does the Dji care do anything if the copter just flies away, never to be found again?

I'm kinda concerned about the compass issue and reliability in general as should it happen it will make all the fancy failsafes useless (especially if the compass doesn't recover at all) and thus I don't really feel comfortable to fly very far. (even in visual range) Not a chance I would fly this over populated areas as some people seem to do after seeing how it can just fail. I will probably get over the initial lack of trust though at some point but this wasn't an optimal start to my multicopter career. (these things should have build in parachutes, really)
2016-7-30
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btreptel
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Australia
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Hey Jarmow

I'm having exactly the same problem but can't seem to get help. Everyone just keeps telling me to re-calibrate the compass but I've tried in the middle of nowhere and I still get the same errors. I can't fly it at all without it switching to Atti mode.

I started a thread about it but no luck so far. I've seen a few people complaining about the same thing but no help so far. One guy sent his back and the new one works ok but it seems weird so many would be having this fault. Could be firmware?

Here is the link to my thread in case someone suggests a fix that works?  http://forum.dji.com/thread-59461-1-1.html

2016-7-30
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labroides
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If you have repeated trouble calibrating the compass look at the compass data shown in the Sensors section of the app settings.
If you are seeing numbers there, that's good.
If you see zero for the compass data, it indicates your compass is busted or (more likely) disconnected and will never calibrate until that's fixed.
2016-7-30
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labroides
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A.  How far?
There's no simple answer, it depends on the size of the steel object.
If you are talking about a car, try to be 10+ metres away.

B.  No .. you need a properly calibrated compass to fly straight

C.  No.  If your compass is not calibrated properly your Phantom won't fly fly away but it won't fly straight.  Switching to atti won't help and if the compass error is bad, the Phantom will probably switch to atti because of the sensor data conflict anyway .. but it still won't help.

Your concept of a compass error is wrong.
A compass error isn't a problem with the compass - it's the compass telling you that it has detected an error and the magnetic field it senses is diifferent from what it is calibrated for.
The most common cause would be calibrating close to a large steel object or on top of reinforced concrete.
Fly out of the magnetic influence and your compass gives you a compass error because it hasn't been calibrated for the earth's normal magnetic field.

Get a good compass calibration and stick with it.
Don't go unnecessarily recalibrating it and risking giving it a bad calibration.
Stay away from reinforced concrete.
2016-7-30
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Jarwa
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Finland
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labroides@yahoo Posted at 2016-7-31 05:47
If you have repeated trouble calibrating the compass look at the compass data shown in the Sensors s ...

Thanks for answering. The thing is that the compass values seem to be ok (last one is somewhere between 1400-1500) when I turn the copter on. I don't remember if I have checked them after my failed attempts but I'm guessing it still saves the "failed" calibration and uses it after I restart the copter. Then the values are always okay, even if right after calibration it said that there is problem with it. But I'll try to calibrate it somewhere far away from anything the next time I'll try it.
2016-7-31
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Jarwa
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labroides@yahoo Posted at 2016-7-31 05:55
A.  How far?
There's no simple answer, it depends on the size of the steel object.
If you are talkin ...

A: Okay thanks. I'll try it in the middle of nowhere next time I'll fly it.

B: By normal I meant that I can still fly it "manually" in A mode. I know that it will not hover in place/will move with wind etc. But shouldn't it still fly normally when gps and compass are disabled in A mode?

C: Okay well good to know those major problems aren't caused by compass error

Well, yeah I know how it's working in general, but how come it says that there is compass error right after calibration attempt but after restarting it it doesn't mention anything about it? (at the same position) I'm kinda sure it still saves the data even if it has errors. Then the error just happens randomly in the air. However if it doesn't save the problematic calibration data then I can understand why it works as it does now.

Thanks for answering. Hopefully it calibrates ok when I try it in the middle of nowhere. Although it seems that some other people have similar issues and different places don't help anything.
2016-7-31
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Jarwa
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btreptel Posted at 2016-7-31 04:33
Hey Jarmow

I'm having exactly the same problem but can't seem to get help. Everyone just keeps tell ...

Hi

Well, that's unfortunate. Maybe the firmware caused it. I should have tried it without upgrading first. I'll try to calibrate it again somewhere far away when I next try it and we'll see. But I don't think it will help. Unless it's the tv transmitter which causes the problem which might be plausible but it's quite far and when flying the compass error isn't continuous so dunno. Hmmh.
2016-7-31
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labroides
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Jarwa Posted at 2016-7-31 18:41
A: Okay thanks. I'll try it in the middle of nowhere next time I'll fly it.

B: By normal I meant  ...

B.  No .. you need a properly calibrated compass to fly straight

You need a properly calibrated compass to fly in any mode
Atti mode still depends on the compass and does not disable it.
2016-7-31
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Jarwa
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labroides@yahoo Posted at 2016-7-31 13:13
B.  No .. you need a properly calibrated compass to fly straight

You need a properly calibrated c ...

Well that's rather strange system then if a failed compass makes it unflyable. But gotta try to calibrate it again somewhere else.
2016-7-31
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