Fixing DJI's Compass Problem

[N017RW]

'Local [magnetic] Deviation' is not referenced or included in FAA sectonals and would be an unnecessary and difficult task to quantify for every airport in the country. I would like to see such a document specifying [local deviation] magnitudes. Additionally, LD simply does not come into play for flight planning.

The FAA uses Magnetic Variation (MV) to describe what is commonly referred to here as Magnetic Declination.

Runway headings provide pilots the opportunity to [officially] adjust their compasses for field MV prior to take off, but even that is subject to the pilot's skill and judgement when aligning his a/c on the runway for comparison.

A magnetic heading is optained by adding or subtracting MV from your true heading.

Agreed, items from inside the airplane (or Phantom) can actually affect the performance of the compass or magnetometer. (The hard and soft iron distortion.)

Thus, as you mentioned, aircraft technicians take account for this and will place a placard beneath the compass displaying the errors for certain headings. True, these errors are referred to as deviation.

By adding or subtracting aircraft deviation from your magnetic heading this will give you a compass heading. A compass heading is the direction you could turn the aircraft to that has been corrected for winds, variation (declination) and (aircraft) deviation.

This is all academic as the Phantom does not have the level of sophistication in its 'avionics' to be able to resolve the minute differences in local induced errors accrued over the short distance or range of the a/c by any possible local magnetic deviation.

Seriously, Who flys their phantom on pre planned compass based courses and experiences difficulties due to the errors? Anyone?

Compairing civil, military, or commercial navigation standards to these, dare I say toys, is apples to oranges.

 

[John Shaw]

I wasn't comparing the use/purpose.
I was just using it to try and illustrate what the aviation community does regarding compass calibration because I don't think we have come to a complete understanding of the dance. Some seem to think it takes care of everything. We know that is not true from our painful declination experience.
The information on the charts I referred to is not the local deviations (which I agree are not shown but occasionally warned about), it is those big dashed lines that slash across from top to bottom to show the magnetic variation (declination).

 

[ianwood]

The Phantom is using the compass pretty aggressively in both GPS and ATTI modes. As we have seen from the declination issues, a discrepancy of only a few degrees between GPS and compass can bring on hooking and at only slightly larger values, TBE.

And to be pedantic, deviation is both what's on the aircraft AND what's local nearby. A/C only really care about the former as the latter is of limited value after take off. The Phantom flies closer to the ground in a smaller area and is more likely to be influenced consistently by local deviation and, as I mentioned above, it is very sensitive to compass errors. That is why when changing location it is recommended to re-calibrate.

As to what the compass dance does, it is measuring background magnetic variance through two axes. A perfectly even environment will show a perfectly linear sweep from 0 through 360 as you rotate the Phantom in each axis. If there are fluctuations, as is common in the real world, those are noted as deviations.

Heading + deviation = actual magnetic heading.
Heading + deviation + declination = actual true heading.

 

[WL Production]

I also have J-hook and TBE issues with Naza-V1.
The body of my Phantom 1 was worn out, so I built a Tarot 680Pro with the Naza-V1 from my Phantom and added a GPS from a Naza-Lite.
The GPS is correctly centered and its position relative to CoG was entered into the Naza-M software. Compass calibration before flight.
Yet, I have magnetic declination issues.
The fix suggested by Ian Wood seems like the way to got... I don't understand why it's not getting done. Why isn't DJI fixing this!
I hope that if they do fix it for the Phantom 2, that they also apply the fix to all other DJI products to include the Naza-V1.

I'm located in Sherbrooke, QC, Canada.
Magnetic declination: -15° 23' WEST, according to magnetic-declination.com.

 

[spunrdneck]

I have been away from the forum for a while and thought I would check in.....

So to summarize, it looks as though DJI has released nothing of a fix yet and this thread is still confused with a discussion of what is and isn't a problem.

Ianwood, I am impressed by your patience in constantly having to explain the KNOWN problem that many don't understand, experience or even comprehend. I sure hope they update soon, while it is really just an inconvenience to most, this hobby is way too costly to allow such an oversight on DJI's part! Especially after the presidential flight failed!

 

[damoncooper]

3.0.6 fixed the issue

 

[MontanaMike]

Hi all.. I haven't posted in a long time, but 3-4 months ago, My p2 had serious TBE here in NW Montana.. I've logged hundreds of flights with 5 different batteries. I'm still on v1.08 because I never had issues from day one besides the TBE and J-hook so I'm ok with leaving well enough alone.. but recently, I've noticed in the last 2-3 mnths, the compass stuff seemed to have cleared itself up. -No issues whatsoever..Same locations, flies straight as an arrow, and no circling from the beginning. I calibrate compass once a month or so, or if I drive more than a hundred miles from home.. Anyone else seen anything similar?

 

[Pilot One]

I just purchased a brand-new Phantom 1 with firmware 4.02. I do feel ripped off. By the time my Phantom flies straight the battery is dead. The Phantom one can fly for seven or eight minutes and five of those minutes it J hooks like crazy and couldn't keep it's heading if it tried.don't forget toilet bowl effect. DJI why are you not listening not making your product work?


If they couldn't even get my version 1 to fly straight after all this time they are laughing at us all the way to the bank.

I came here in support of all you Phantom pilots. In my research trying to find a solution which lies in the hands of DJI and they're neglecting their responsibility .

I ended up here as I was asked to be here. Not what I was hoping for purchasing a Phantom.

Thanks DJI

 

[HarryT]

I just purchased a brand-new Phantom 1 with firmware 4.02. I do feel ripped off. By the time my Phantom flies straight the battery is dead. The Phantom one can fly for seven or eight minutes and five of those minutes it J hooks like crazy and couldn't keep it's heading if it tried.don't forget toilet bowl effect. DJI why are you not listening not making your product work?

Are you sure you have firmware 4.02? The current firmware version is 3.06, unless the P1 runs different firmware?

3.06 "learns" how to correct for magnetic declination, which should eliminate the problem.

 

[Pilot One]

Are you sure you have firmware 4.02? The current firmware version is 3.06, unless the P1 runs different firmware?

3.06 "learns" how to correct for magnetic declination, which should eliminate the problem.[/quote]

yes as far as I know it's completely up to date. I did notice the numbers changed between version 1 and version 2 for firmware. So you're telling me Phantom 2 will permanently remember and is really really fixed. If this is true and they left version 1 behind is very sad indeed.

Can you please tell me about firmware 3.06 does it really remember without having to go through the startup figuring out how to correct for the magnetic declination with every fresh battery. How well does it work. Why am I left behind being punished just because I have an earlier version which should have been fixed already.naturally I have lost a bit of interest here and if you have flown with a wild J hook and crazy rotation that spins out of control from hover. it was still expensive not such a nice feeling.

pilot one hoping for a fix

 

[HarryT]

Can you please tell me about firmware 3.06 does it really remember without having to go through the startup figuring out how to correct for the magnetic declination with every fresh battery. How well does it work. Why am I left behind being punished just because I have an earlier version which should have been fixed already.naturally I have lost a bit of interest here and if you have flown with a wild J hook and crazy rotation that spins out of control from hover. it was still expensive not such a nice feeling.

pilot one hoping for a fix

Yes, 3.06 really does learn and remember, which is very useful for those who live in areas of high magnetic declination.

Apologies - never having owned a P1 I was unaware that its firmware was different to that of the P2.

 

[Pilot One]

hi everyone DJI contacted me and said they believe my GPS and compass are not in agreement to which way true North is,then went on saying that we are not calibrating our phantoms to the location of the world that we live in. What special calibration I am a beginner but what are they talking about?

I found my declination myself from magnetic declination.com which said that where I live is Magnetic declination: +16° 29' EAST
Declination is POSITIVE

Then DJI told me after I calibrate this I'm good it should fly as intended. But they never told me how to calibrate it

I do not see anything in the assistant software for custom telling Phantom were true North is. What do you think DJI was asking me to do?

Does anyone here know?

 

[Guipago]

hi everyone DJI contacted me and said they believe my GPS and compass are not in agreement to which way true North is,then went on saying that we are not calibrating our phantoms to the location of the world that we live in. What special calibration I am a beginner but what are they talking about?

I found my declination myself from magnetic declination.com which said that where I live is Magnetic declination: +16° 29' EAST
Declination is POSITIVE

Then DJI told me after I calibrate this I'm good it should fly as intended. But they never told me how to calibrate it

I do not see anything in the assistant software for custom telling Phantom were true North is. What do you think DJI was asking me to do?

Does anyone here know?

Your not alone, my FC40 has 4.02 & does the same thing, I've tried compass calibration every battery, IMU calibration, basic & advanced, waved a magnet around till i'm blue in the face & still flys left & when you stop it goes about 8 meters left if I don't correct it, all very disappointing, hope you get some clearer instructions from DJI, I'm all eyes & ears!

 

[Chris Davidge]

Hi
I have a FC40 too and have the toilet bowl effect when in GPS mode, is it only drifting left and not in circles?
I have also tried everything to fix my problem and not having luck

 

[Pilot One]

Guipago
Your not alone, my FC40 has 4.02 & does the same thing, I've tried compass calibration every battery, IMU calibration, basic & advanced, waved a magnet around till i'm blue in the face & still flys left & when you stop it goes about 8 meters left if I don't correct it, all very disappointing, hope you get some clearer instructions from DJI, I'm all eyes & ears![/quote]

update,I tried to speak to a representative and got redirected to Flying Camera (Canada)the technician asked me today if I am getting 12 satellites. The technician said I need 12.

The indicator lights that's all we have and we know solid green means 7+ satellites there is no other indicator

this doesn't make any sense. When I talked about magnetic declination her technical back seem to go up against the wall and she deflected everything. How do you get customer support? I'm not the only one with a Phantom that likes to drift off course.

I give up because every single effort I have made has been deflected and I am tired of this kind of disrespect. My Phantom is still fun but as for the fix hopefully somebody else will take over the battle.

Okay DJI I give up

 

[Dave Pitman]

UPDATE:

It's fixed. Download 3.06, install, recalibrate everything and enjoy. Below is the history of the issue:

As of July 14, 2014, there are 139,765 P2 users of all sizes and flavors reporting the same issue. If you are affected, make sure you say so here! Apparently Barack Obama crashed his P2 in the rose garden after it hooked into a trellis on July 4th weekend. He wasn't impressed. Says he wants DJI to fix it ASAP. (Washington DC is -12 magnetic declination.)

Here is what we know about the problem so far:

• Affects all P2x in areas of high magnetic declination (+/-8 or higher).
• Curved flight and hooking is worst when first flying. It improves during flight but may take several minutes.
• Beta 2 of the 3.05 firmware remembers adaptions between flights.
• It appears to not affect the P1.
• Areas with very high declination will experience TBE during initial hover.
• Several people have returned their P2x thinking it was defective only to get a new one with the same problem.
• This is a firmware defect. Possibly a signing bug in the code.
• This defect is still present in all firmware versions up to 3.04.
• Measuring the angle between initial true heading and initial course lock heading will give you the real margin of error.
• Rotating the compass is not a recommended workaround.
• Using a very rough bottom up model, it is expected that at least 1 in 4 P2x users experience this problem.
• DJI beta firmware 3.05 has been tested and confirmed it is 80% improved.
• DJI is working on a revised beta firmware for further testing.
• The beta test group is limited in order to maintain control of observed results.

Fixing DJI's Compass Problem

Some of you know about this and some of you aren't affected. If you live in the following areas, you are subject to this problem even if you don't know it:

• Western US and Canada
• Northeastern US and Canada
• Eastern OZ and all of NZ
• Northeastern South America
• Southern Africa

Your compass and GPS are disagreeing over which way is forward. This results in curving (hooking), tracking to the left or right in GPS and course lock, and/or not hovering in place. This is a caused by a defect in DJI's firmware which they need to fix.

[youtube]http://www.youtube.com/watch?v=9BUilGeH74Q[/youtube]

I am working through some contacts to get in touch with DJI's LA office to present the issue in a clear fashion along with the backing of the user communities like this one. Most importantly, I want to show them how many other people have this issue.

If you are in one of the areas above, confirm in this thread that you have experienced this issue. I have written a complete summary of the issue here: DJI Phantom and Magnetic Declination which I will be sharing with DJI as well. Please share this so that we can collect as many of the affected users as possible.

And before anyone says "Just rotate your compass", that is not the answer. DJI has said so themselves. If you wish to discuss rotating the compass, there are threads dedicated to that discussion.

You may want to amendment this post to reflect that the problem does affect P1s and FC40s which run different firmware, and has not been addressed.

 

[Pilot One]

Dave, I wish to correct and reiterate that Phantom 1 is also affected

My saving grace is the toilet bowl effect is rare I have not seen it lately. And I know to fly out of it immediately

As for the J hook syndrome yes it is a nuisance and while it fades away it does take half of my battery pack to do it.

I hope DJI has 1 more firmware up their sleeve from what they've learned so the Phantom's can be what they were intended to be. The best quad in its class.

I can fly my Phantom and it is fun., But It would be nice to see my Phantom fly straight. :?:

Update, great news for all Naza M DJI announced a new update soon for the Phantom 1. Tahoe Ed gave the good news the J hook syndrome will be addressed finally.

you all know the Phantom 2 version 3.06 firmware added memory to the learning of the GPS it will be addressed soon to the Phantom 1 . Thank God for DJI

This instills new faith we are all looking forward. Hopefully we won't have to wait much longer to fly in a straight line.

 

[Guipago]

This is GREAT news, I only hope they don't load up the software with the same "saftey" parameters that the phantom 2 guys got stuck with!(maybe a few more instructions in the manual for those that don't understand flight & it's rules instead of penalising those that do)

 

[ianwood]

So all Naza M are getting auto-declination? That's good news!

 

[poostik]

Hate to ask a question that's probably already been answered but is there any problem rolling back to previous firmware from 3.06?

I want the compass problem fixed but in some cases, I want the old tilt I get from 1.08. When I ran 3.x it was so slow, I couldn't keep up with a boat, going just over 20mph. :-/ I need the straight flying though, for some of the other stuff I'm shooting that isn't moving.

Even better . . . Is there anything I can do to not have the compass problem AND go faster? The new prop/motor upgrade maybe?