Fixing DJI's Compass Problem

Cor Brink,
TBE manifests itself when fingers are off the sticks, i.e. when attempting to over in a stationary position, so finger-trouble is NOT the cause.

For those of us who are experiencing this problem (as few as we might be), it is indeed a very serious problem, and needs addressing by DJI. Refusing to accept that a problem exists, does not make it go away.

BTW, many of us are experienced RC pilots who fly other much more difficult aircraft such as RC Heli's, so do not be so quick to blame this on a newbie issue. Many of us are also real pilots of real aircraft as well.

The problem exists. It can be proven very easily with video footage, with hands-off the controller.
Today I had my Phantom 2 scribe a 15 meter diameter TBE for at least 8 minutes before it reduced to a reasonable size of about 2 meters. By the time it reduces to zero, the battery is exhausted. Swapping batteries just starts the problem all over again.

I do commercial aerial filming in the TV commercial arena and often need to fly in tight spaces between buildings.
This is simply not possible in GPS ATTI mode when a stationary aerial camera is called for.

The Blade 350 QX never does this. It does not even have a procedure for compass calibration, nor is there a USB port for updates, yet it flies perfectly out of the box, every time.
 
Cor Brink said:
Being an airline pilot makes me question the things you all say here.
How many phantoms do you think have been sold and how many complain? Of the 200 members on this forum there's less than a quarter that has compass issues.
Do the maths and you'll probably realise there's more finger trouble amongst the complainers than anything else.
These are probably also the same people that 'root' and 'jailbreak' their phones and wonder why it's broken.
You're farting against thunder.

Nothing wrong with questioning, and pilot error certainly needed to be ruled out. However, you have now made it clear that you have not taken the trouble even to read enough of the thread to figure out the flight behavior under discussion, let alone grasp the concepts that have been hypothesized to explain it, whether they are correct or not.

Thanks for offering that you are a pilot, but I'd have to suggest that a pilot of any kind would not confuse the terms "bearing" and "heading" and, while you would be used to expressing direction in degrees magnetic, that you would also be aware that modern autopilots get heading data from inertial instruments that reference true north, rather than from magnetic compasses that would require declination correction.
 
If this is a problem related to declination:
For a little perspective in relation to Cor Brink's comments of only a small portion seem to have the problem. I downloaded the world declination charts and colored in the areas that have less than 10 degrees declination. If you assume that a fair percentage of the people with less than 10 degree declination wouldn't be aware of the problem even if they had it - it gives some perspective as to why everyone doesn't see it. You can mentally adjust if you think the cutoff percentage is different. It clearly shows why not everybody would be aware of the problem - including DJI.
 

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Far North of NSW East Coast Australia

Hi I live on the Far North of NSW around Byron Bay East coast Australia ( 28°38'45.22"S - 153°37'39.55"E )

I ran the tests being careful with the controls and noticed it hooking to the left when moving away and to the right when returning.

Was surprised I had not noticed this before I put it down to the wind From what I been able find out my declination is +12

I tried doing a complete recalibrating the phantom and redid the test Same thing again...

Thanks IAN for trying to sort this problem out

I hope DJI take your suggestions and do something to make a fix
 
Re: Far North of NSW East Coast Australia

AviZ said:
Thanks IAN for trying to sort this problem out

I hope DJI take your suggestions and do something to make a fix

It looks like they are looking at it. If you want to beta test, sign up here: viewtopic.php?f=19&t=11555
 
Getting my new P2Z with version 2 firmware off the bench I had this problem.
System: P2Z (H32D) / Futaba T14SG / Flytrex Core / Immersion RC 600mW / Removed original reciever and installed R7008SB
All controls and gimbals calibrated on bench prior to installing props
Tried updating all firmware including iOSD
Tried recalibrating compass
Had and worked around the "overheating problem" when doing an advanced IMU recalibration

I am just outside of Toronto.
Ended up downgrading to 1.08 and the problem was solved
Flying in PHANTOM mode / GPS not NAZA / GPS.
Same problem of left drift and ended up tipping to the left.

My P2V with stock transmitter does not do this and is on the 1.08 Firmware. I have not "upgraded"

Thank you Ian for getting the ball rolling. I have an iOSD and Flytrex but not Mini-OSD as required in the Beta thread. Otherwise I would be in.

I don't know if this helps DJI but I would note the following
On Advanced calibration, here are my compass readings:

Version 1.08
Compass (raw) X 251 / Y 107 / Z -54 / Mod 663.8

Version 2
Compass (raw) X 250 / Y 100 / Z -50 / Mod around 1600 if I recall correctly.
 
Had major compass problems.. Central British Columbia.. Copter skews about 15 degrees left, rather than flying in the direction it's pointed.. Major left hook after a straight run -- 50 feet .. Toilet bowl effect 10 to 30 feet.. I replaced the compass.. No change. Did notice slight improvements after in operation for a period of time.. Currently with dealer to repair. Will not hover.. If you rotate, the copter slips into the toilet bowl effect.
 
Cor Brink said:
Being an airline pilot makes me question the things you all say here.
How many phantoms do you think have been sold and how many complain? Of the 200 members on this forum there's less than a quarter that has compass issues.
Do the maths and you'll probably realise there's more finger trouble amongst the complainers than anything else.
These are probably also the same people that 'root' and 'jailbreak' their phones and wonder why it's broken.
You're farting against thunder.

Do I "root" and "jailbreak" my phone? No.
Am I just a complainer? No.
Am I just farting against thunder? No.
I have two Phantom 2s and another one (with 3D gimbal) on the way. I have a friend here in ChCh NZ who has a Phantom 2 and we are having the exact same problems with all these machines. They all exhibit TBE etc. I took my first Phantom 2 to India (where magnetic declination is 0) and after calibrating the compass, had no issues at all.
I've had a number of DJI flight controllers and this same issue was present a year or so ago with the Wookong. DJI came to the party and provided replacement v2 GPS/Compass units which solved the problem.
You may be a pilot, but I fail to see how flying a plane is comparable to the issues we're having. After all, if commercial planes exhibited TBE, there would be a lot more dead people, right?
 
Re: Far North of NSW East Coast Australia

ianwood said:
AviZ said:
Thanks IAN for trying to sort this problem out

I hope DJI take your suggestions and do something to make a fix

It looks like they are looking at it. If you want to beta test, sign up here: viewtopic.php?f=19&t=11555

Hi Ian. I thought that by adding our comments/stories to this thread, we'd be in the loop to get involved in the beta testing? Is that not correct? The link you provided takes us back to page 1 of this thread. Are we supposed to PM Terry?
 
In Westchester Couty, NY here, also having the same problem with drifting to the right and not hovering steady…haven't had much flight time due to the weather and work but the few times I've been flying have made it not a good experience for someone new to flying, thats for sure. Actually almost afraid to fly it worrying that its gonna hit something. I actually thought it was the wind at first but after reading up on it I see it probably isn't the wind at all….Gonna try to get out for a bit today before going back to work tonight if the weather clears up a bit…will post more results if I do get out there... Hope they can fix this problem soon because I am really disappointed as of right now. Just got my FPV system hooked up and was looking forward to practicing and doing some video.
Add me to the list please.
 
Well got a little flight time today and it did exactly what you guys said…tracked to the right while flying straight then when hovering did that toilet bowl effect and even seemed to drop a bit as it hovered…after a few minutes of flying it seemed to be batter but still makes flying a little scary…was a little windy but nothing that should affect this stuff especially at low altitudes…Thanks Ianwood for making this thread and getting everyone together here with the same problems…I really hope DJI can fix this problem soon...
 
I was hoping that the latest P2 Assistant software, version 3.0, would fix the hooking and TBE problems.

I successfully updated the software, then the main controller firmware. I did an advanced IMU calibration* and a compass alignment. The problems remain. The 3.0 versions did not fix the hooking or TBE.

*FYI, when I get the "controller temp is too high" language, as I do more than half the time when doing an advanced IMU calibration, I immediately hit "OK" and then immediately hit the "start" button again. It's not necessary to shut down or allow cooling time, because nothing is actually overheated. It's just some kind of software snafu, in my opinion, that can safely be ignored.
 
i dont know if it was mentioned on the past pages but you can check your magnetic declination by GPS with "declination" iphone app.
 

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I had some serious compass problems today. My phantom 2 vision started doing large fast loops (sticks centered). Almost flew into a tree before i understood whats going on and switched to Atti mode and landed. The aircraft didn't ask for a compass calibration after power-cycleing but i tried to calibrate anyway - couldn't get a calibration. Only could calibrate after i changed location.

After calibrating i did a test flight - no flying loops, but noticed the J-hook just like described here. Now that i think about it, i noticed the j-hooking before but paid no attention to it.

My Phantom Vision's j-hooks:
https://www.youtube.com/watch?v=W94dy8P-UGk
 
A video of my test results here in NZ. The compass was rotated 41degrees clockwise, stopping the TBE.
Please bear in mind that prior to this modification, I was getting more or less constant TBE.
https://vimeo.com/91571696
 
When doing the vertical compass calib in the southern hemisphere should we point the front up ??? I did it as described in the manual but just curious if it might need a 180 flip down under ???

Sent from the thing that does everything.
 
Mandrake said:
When doing the vertical compass calib in the southern hemisphere should we point the front up ??? I did it as described in the manual but just curious if it might need a 180 flip down under ???
Lol. Since the North Pole is north of Australia, and of everywhere else on Earth, wouldn't the compass calibration work the same as everywhere else? That said, I'm curious if a Phantom would accept a nose-up second stage of compass calibration. My instincts tell me no, or that it would be a really bad calibration, but I don't have enough actual knowledge to know.
 
Add me to the list. Same issue here as the others, and I am located in Pensacola, which is literally at 0 declination.
 

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