Hi,


Hoping somoene can give some advice on this isssue I am having. Only recently I have started to enocounter issues during flight rendering my P4P very unstable.


I am recieving a number of errors which are:


Compass error. exit GPS mode
Weak GPS signal
IMU encounters heading exception


I havent had this before until my last two flights and reciving the above errors on both occasions even though I have calibrated all systems and shwoing no less than 16 satalites locked on.


Any ideas approceiated.


Thanks,


Anthony

You usually get this warning due to compass interference followed by IMU heading, then your AC may go to Atti mode.
What causes it, it may be you took off from an area with some magnetic interference which could have effected your compass causing your problems.
Rebar concrete metal structures etc, or you could have got some interference around where you were flying.

You could click on link and follow instructions below and come back here and post your link, you will get more precise information on what could have happened.

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

like what Hallmark007 said, maybe you were in an area of alot of magnetic area, post your logs and see, maybe someone can help explain this

hallmark007 Posted at 2017-11-19 03:07
You usually get this warning due to compass interference followed by IMU heading, then your AC may go to Atti mode.
What causes it, it may be you took off from an area with some magnetic interference which could have effected your compass causing your problems.
Rebar concrete metal structures etc, or you could have got some interference around where you were flying.

Thank for the reply. Its an area of have used a number of times without issue. Have recalibrated everything and still the same issue. Making it pretty unusable at the moment.

Here's a link to the flight file. Hopefully someone can help so I can get back on the job : )


http://www.phantomhelp.com/LogViewer/9LD074Z4HQ42T0MJPUU4/

I experienced the same thing yesterday I was flying along the river broad walk and I kept getting compass error going into Atti mode, this was because of the metal around me. Maybe you have a bad IMU or the compass is off.

Any DJI reps can assist?

BagoDJIoperator Posted at 2017-12-11 10:08
I experienced the same thing yesterday I was flying along the river broad walk and I kept getting compass error going into Atti mode, this was because of the metal around me. Maybe you have a bad IMU or the compass is off.

Strangely only had it recently after the update.... I have recalibrated everything and there isn't any metal around for some distance. Picking up 16/17 satellites but the GPS icon drops thew bars completely even when showing 16/17 locked on.

Micro Pilot Posted at 2017-12-11 10:46
Strangely only had it recently after the update.... I have recalibrated everything and there isn't any metal around for some distance. Picking up 16/17 satellites but the GPS icon drops thew bars completely even when showing 16/17 locked on.

Are you using the remote with the built in screen? Maybe try and update the app or reload the firmware and reset the drone. Hope this helps, you I'm having the same issues myself.

Micro Pilot Posted at 2017-12-11 09:12
Here's a link to the flight file. Hopefully someone can help so I can get back on the job : )

I can only think that there was some magnetic interference in the area that day, or when you calibrated you ended up with bad calibration and you have said that you’ve been out since and you had the same problem, can I ask were you in a different area the second time. Also do you have any add on attachments added on to the drone ie tracker etc ?

BagoDJIoperator Posted at 2017-12-11 10:51
Are you using the remote with the built in screen? Maybe try and update the app or reload the firmware and reset the drone. Hope this helps, you I'm having the same issues myself.

Nope, using iPad Pro. Have used the same one since getting the P4P

hallmark007 Posted at 2017-12-11 10:58
I can only think that there was some magnetic interference in the area that day, or when you calibrated you ended up with bad calibration and you have said that you’ve been out since and you had the same problem, can I ask were you in a different area the second time. Also do you have any add on attachments added on to the drone ie tracker etc ?

Tried the same area on several occasions and also completely different areas separated by 50miles or so. Still same issue. All started after there latest update.

Micro Pilot Posted at 2017-12-11 11:12
Tried the same area on several occasions and also completely different areas separated by 50miles or so. Still same issue. All started after there latest update.

The problem lies with your compass, it’s not IMU , IMU exception only occurs as a direct result of compass problem.

Micro Pilot Posted at 2017-12-11 11:12
Tried the same area on several occasions and also completely different areas separated by 50miles or so. Still same issue. All started after there latest update.

Maybe put in a troubleticket with DJI and hope they can fix it

Lodged a ticket with DJI support and received the following recommendation...

To isolate the issue on the Phantom 4 PRO. we would need to perform a refresh of the firmware of your aircraft.
This process is not going to update the firmware of your drone but it will repair the firmware of your drone. We will be able to isolate the issue that you are experiencing if it was a software or hardware problem.
To perform firmware refresh:
> Install the DJI Assistant 2 on your computer: https://dl.djicdn.com/downloads/ ... sistant+2+1.1.6.exe
> Login to DJI Assistant 2 using your DJI Account.
> Under Firmware tab, click on the refresh icon in the top right corner of the screen to start the refresh process

So after doing this and updating to the new software still the same issues. I think a hardware issue? What do you think?

So update.....

Sent back to service centre and they have emailed today confirming free replacement.

What is the ambient temp. when you receive these warnings?

Rodger8 Posted at 2018-2-14 12:38
What is the ambient temp. when you receive these warnings?

Between 1-8celcius on test days

Micro Pilot Posted at 2018-2-15 02:45
Between 1-8celcius on test days

I have GPS disconnects at 1-3 c

Rodger8 Posted at 2018-2-15 04:12
I have GPS disconnects at 1-3 c

Could possibly be the same issue... It was connected on take off then as soon as a few meters out it drops gps with errors. Anyway DJI have replaced and its being shipped back now.

Micro Pilot Posted at 2018-2-15 09:21
Could possibly be the same issue... It was connected on take off then as soon as a few meters out it drops gps with errors. Anyway DJI have replaced and its being shipped back now.

I proved it out. In 40f plus temps there are no issues.

Rodger8 Posted at 2018-2-15 11:53
I proved it out. In 40f plus temps there are no issues.

Well DJI agreed an issue and replaced so all good : )

Micro Pilot Posted at 2018-2-19 10:44
Well DJI agreed an issue and replaced so all good : )

Did they confirm that it was a temperature issue?

Rodger8 Posted at 2018-2-19 12:11
Did they confirm that it was a temperature issue?

Nope no real confirmation

Micro Pilot Posted at 2017-12-11 10:46
Strangely only had it recently after the update.... I have recalibrated everything and there isn't any metal around for some distance. Picking up 16/17 satellites but the GPS icon drops thew bars completely even when showing 16/17 locked on.

Please answer these

1- From the time you turn on the AC, how long before take off?  10-30 seconds? 2-4 minutes?

2- Even with lots of Sats, are you taking off before a solid Green READY GPS......no flashes of IMU/Compass/Can Not Take Off
BTW, I realize you are all set.......just curious about those questions......

Thx
Randy

rwynant V1 Posted at 2018-4-27 15:52
Please answer these

1- From the time you turn on the AC, how long before take off?  10-30 seconds? 2-4 minutes?

Hi Randy,

Usually around 1-2mins and when I have solid Green GPS lock. No flashes of errors.

Oddly I have taken it out this morning and encountering the same issues again

Micro Pilot Posted at 2018-4-28 22:54
Hi Randy,

Usually around 1-2mins and when I have solid Green GPS lock. No flashes of errors.

What surface are you taking off from?

Geebax Posted at 2018-4-29 01:26
What surface are you taking off from?

From various. Grass, concrete, plastic table.

Micro Pilot Posted at 2018-4-29 11:12
From various. Grass, concrete, plastic table.

That might be your problem. Never take off from concrete, it often contains steel rebar which will give you a compass error just after take off. Even a plastic table is a problem, does it have a steel frame? Best to take off from grass.

Geebax Posted at 2018-4-29 16:45
That might be your problem. Never take off from concrete, it often contains steel rebar which will give you a compass error just after take off. Even a plastic table is a problem, does it have a steel frame? Best to take off from grass.

Even on grass after reset its the same.