Hi,

today I was flying my Phantom 3 Standard around my back yard. Done it couple of times. I was testing maximum range and hit 822m when i got warning and Phantom automatically started return to home sequence. Picture came back at 757m so a canceled RTH function and was headed back. At 738m picture got lost again for a while and than at 660m with good signal it switched to ATTI mode followed by [url=]Warning:Compass Error. Exit P-GPS Mode[/url]and [url=]Warning:Abnormal compass function or GPS signal detected. Aircraft switched to ATTI mode.[/url] At that point I was flying manually. Luckely I had a good RC and WiFi signal so I could see where I was going as I was constantly adjusting the movements of cross winds. It wasnt a lot, but it was.

I guess if it would have happened a bit far away while connection was lost it would fly away!

Now to the point. Can anyone explain why compass error would ocur? I flew this area quite some times and all was good before.
Please check out my flight log here:
http://healthydrones.com/main?share=fdBCog

It happend once again later in the evening at only 55m away and also at the area that I flew before.
Please check that log too:
http://healthydrones.com/main?share=uaWofm

Maybe important information. I do calibrate compass every flight, also if it is at the same location. I did IMU calibration once when I bought Phantom 3 Std and flew 2.5h, 13.276 meters and total of 26 flights. Phantom is 10 days old. FW is 1.7.9 (latest)...


Thank you for your advice!

Best,
Aljaz

'Maybe important information. I do calibrate compass every flight, also if it is at the same location.'

There is your problem. Despite what DJI and many people say, it is not necessary to perform a compass calibration every flight, and doing so increases your chances of getting a bad calibation. A compass error means the aircraft encounters a conflicting compass reading during flight to the conditions under which it was calibrated.

Do one good calibration and leave it. I have flown my P3P for over a year without re-calibrating the compass and I have NEVER had a compass error in flight. But do the calibration properly, well away from any metal or concrete, preferably in an open field on grass.

Geebax Posted at 2016-12-29 14:35
'Maybe important information. I do calibrate compass every flight, also if it is at the same location.'

There is your problem. Despite what DJI and many people say, it is not necessary to perform a compass calibration every flight, and doing so increases your chances of getting a bad calibation. A compass error means the aircraft encounters a conflicting compass reading during flight to the conditions under which it was calibrated.

Must agree used to do it regularly with a phantom 2 vision +.Soon realised it was'nt necessary.In 2 years plus i cant recall calibrating compass on my pro3 more than a few times.

Propwash Posted at 2016-12-29 18:49
Must agree used to do it regularly with a phantom 2 vision +.Soon realised it was'nt necessary.In 2 years plus i cant recall calibrating compass on my pro3 more than a few times.

Well, that actually makes sense. Thank you for your tips, guys! Will do a good calibration at open area and try future flights without calibration and report.

Thanx again!

All compases rely on the strength of the earths magnetic field. You can calibrate the compass as many times as you like, but if a coronal mass ejection from the sun arrives at earth, you get a spike of charged particles hit the earths magnetic field and shock it, the earths magnetic field reverberates for a few seconds, and you get your compass error. The suns coronal mass ejections are linked to its 11 year sunspot cycle. So at the maximum sunspot activity in this cycle you will get these errors frequently. When sunspot activity is at its minimum, you will get few of these errors. Nasa runs a site where you can check sunspot activity and status and arrival times of coronal mass ejections.

http://www.swpc.noaa.gov/

Have a look at the linkThese mass ejections also affect radio waves at most frequencies, below is the link to the radio frequency disturbance prediction page.

http://www.swpc.noaa.gov/communities/radio-communications


A lot of lost comms , video , and RC signal as well as compass errors will be mostly due to these geo magnetic storms, when comms are lost in non built up areas, with no power lines or known strong magnetic sources. I know a lot of complaints are put on the forum for lost comms of one type or another, with DJI not being able to come up with a reason why. GMS ( geo magnetic storms ) are the likely culprit in nearly all cases.

Well look at SPIKE_151! Thank you Mr. Astrophysics.

BillW50 Posted at 2016-12-30 02:05
Well look at SPIKE_151! Thank you Mr. Astrophysics. http://i.imgur.com/rPrKVpp.gif[/img]

30 years as an amateur astronomer helps with this stuff

SPIKE_151 Posted at 2016-12-30 01:44
All compases rely on the strength of the earths magnetic field. You can calibrate the compass as many times as you like, but if a coronal mass ejection from the sun arrives at earth, you get a spike of charged particles hit the earths magnetic field and shock it, the earths magnetic field reverberates for a few seconds, and you get your compass error. The suns coronal mass ejections are linked to its 11 year sunspot cycle. So at the maximum sunspot activity in this cycle you will get these errors frequently. When sunspot activity is at its minimum, you will get few of these errors. Nasa runs a site where you can check sunspot activity and status and arrival times of coronal mass ejections.

http://www.swpc.noaa.gov/

Very interesting!

I had a compass malfunction on my last flight,first time this has happened, I was flying over a Loch when the error showed up and my phantom started to drift all over the place,luckily I had it in sight and was able to fly it home safely,at the time I was in course lock mode and I did not calibrate the compass before I took off,also the return to home mode popped up on the app but the phantom took of and the return to home failed.

I did a new calibration of compass once more at new location, with probably no interference and did not experience the same error so far. So, thank you once more. I hope it will stay this way! ;)

If any of you have any issues with RTH for compass failures or the like, switch the drone into atti mode with the Atti/sport/gps toggle top left of the controller, fly up to an altitude that clears any obstacles that you can see, then look at your radar on the phone/tablet. Point the arrow at  your take off point and fly the drone back to your take off point, this is quite easy to do, and should be learnt for when your drone is out of sight by eye.

Great advice, Spike! Thanx!

SPIKE_151 Posted at 2017-1-25 00:30
If any of you have any issues with RTH for compass failures or the like, switch the drone into atti mode with the Atti/sport/gps toggle top left of the controller, fly up to an altitude that clears any obstacles that you can see, then look at your radar on the phone/tablet. Point the arrow at  your take off point and fly the drone back to your take off point, this is quite easy to do, and should be learnt for when your drone is out of sight by eye.

"if any of you have any issues with RTH for compass failures or the like, switch the drone into atti mode"

Compass errors are almost never compass failures.
If you have a compass error because you screwed up your compass calibration unnecessarily calibrating on reinforced concrete, your Phantom will already be in atti mode because of the data conflict and setting the switch will make no difference.
And if it's the compass that's the problem, you've still got a big problem as you won't be able to fly straight.

Labroides, are you suggesting that if the compass is not calibrated , the radar on the tablet is ineffective?

Labroides Posted at 2017-1-25 01:28
"if any of you have any issues with RTH for compass failures or the like, switch the drone into atti mode"

Compass errors are almost never compass failures.

If you switch in atti mode , and fly back using the radar, the drone will not be able to switch itself back into GPS mode and do something you are not expecting. Hence my advice, I have done this myself several times and have had no issues whatsoever getting my drone back safely.

SPIKE_151 Posted at 2017-1-25 00:30
If any of you have any issues with RTH for compass failures or the like, switch the drone into atti mode with the Atti/sport/gps toggle top left of the controller, fly up to an altitude that clears any obstacles that you can see, then look at your radar on the phone/tablet. Point the arrow at  your take off point and fly the drone back to your take off point, this is quite easy to do, and should be learnt for when your drone is out of sight by eye.

Get very confused with these things!!   Doesn't  the radar and the direction the indicator is pointing, rely on the compass working ok?

I flew yesterday afternoon, in a field/park far from cel towers and other electrical interference, and got many compass and gps errors.  I have calibrated my compass once (and have only owned the P3s for 2 weeks).  Here's my log file - using the 1.8.x firmware and Go v3.1.2 on iOS.

http://www.phantomhelp.com/LogViewer/F70LB087AJTBAQSYVFHP/

Anyone see anything that something I can take care of?

Being a beginner in this hobby I was wondering if anyone has written a emergency procedure handbook so us beginners would know what to do in case we  lose signal or compass error etc?

SPIKE_151 Posted at 2017-1-25 05:24
If you switch in atti mode , and fly back using the radar, the drone will not be able to switch itself back into GPS mode and do something you are not expecting. Hence my advice, I have done this myself several times and have had no issues whatsoever getting my drone back safely.

If you have a compass error the Phantom automatically switches itself to atti mode without you doing anything.
If you have a serious compass error you will have difficulty whether you switch to atti or not.
The most common cause of compass errors is unnecessary bad compass calibration.

Watch this for an example:  

SPIKE_151 Posted at 2017-1-25 05:22
Labroides, are you suggesting that if the compass is not calibrated , the radar on the tablet is ineffective?

I was saying that with a badly calibrated compass (compass error) you have trouble flying straight.
See post #19 above.

GeoffN Posted at 2017-1-25 07:28
Get very confused with these things!!   Doesn't  the radar and the direction the indicator is pointing, rely on the compass working ok?

Ive had a compass malfunction several times on my P3s and have flown back using the radar. So I am not sure it is totally reliant on the compass only. Perhaps DJI Mindy can give us the bottom line on the radar.

Labroides Posted at 2017-1-25 13:41
If you have a compass error the Phantom automatically switches itself to atti mode without you doing anything.
If you have a serious compass error you will have difficulty whether you switch to atti or not.
The most common cause of compass errors is unnecessary bad compass calibration.

I appreciate that Labroides, my point is, in gps mode, if signal to gps is lost or has intereference, the craft with switch automatically into atti mode, and will stay in that mode unless the interference goes or the gps lock comes back, then the craft will switch straight back into gps mode. It may well do something unexpected at this point. Hence my advice to switch into atti mode with the toggle, once it is in atti mode with the toggle, gps cannot come back in.

At the end of the day its personal preference in what you want and how you fly. Some people are scared of atti mode because they are not comfortable flying by radar.I personally think that the more modes you are comfortable flying in , the more accomplished pilot you will become.