Fixing DJI's Compass Problem

[sar104]

Either some of us have different definitions for deviation or people might be getting a little confused. The compass calibration that you currently do is for deviation. It measures a full circle in two axes to get the "background" magnetic fingerprint. That includes all your gear that you've stacked onto your Phantom and the environment you happen to be flying in.

Other than local field calibration, there is no other way to compensate for deviation.

Andy, depending on which Android device you have and how old it is, it could be using GPS derived course which is only determined after you establish a clear pattern of motion. Or, it is using an internal compass in your phone.

Nope, What you are referring to is Declination ( local magnetic interferences) . Thats what compass calibration Zeros out. Deviation(or variation) is the difference between True north & magnetic north, which varies depending on location & time (as it drifts over time) Compass calibration does not correct this.
Suspect now the issue may be the fact the GPS is set to reading true north values ( same as a map) & the compass magnetic north values. However can you explain the dynamic relationship, in the auto pilot of the NAZA software, of the GPS, compass & barometer. are they connected?, do they give positive feedback or do they operate independently ?ie. gps for position, compass for heading & barometer for height. Do you have any insight it to the science behind how an auto pilot system works, as there seems to be very little material on this on the net.

You have the definitions of declination and deviation completely confused. Declination is, as repeatedly stated here, the difference between true north and magnetic north, while deviation refers to local field variations.

Your interpretation of the problem is likely sort of correct, but then it has been the entire topic of this thread for several months. Once again, you really need to read before posting.

 

[N017RW]

This is fascinating...

...deviation, declination, inclination, variation, hard-iron distortion, soft-iron distortion, degaussing,... anybody can be a WiKi expert so why the continual pedantic back-and-forth about this?

 

[sar104]

This is fascinating...

...deviation, declination, inclination, variation, hard-iron distortion, soft-iron distortion, degaussing,... anybody can be a WiKi expert so why the continual pedantic back-and-forth about this?

Who are you asking? The guy who keeps posting garbled misinformation and clearly has never looked at any kind of wiki, or the rest of us who are trying to have an intelligent conversation about the problem? It is not, IMO, pedantic to attempt to get the most basic terminology correct, nor unreasonable to hope that posters will make at least a token effort to read the topics and grasp the issues before pronouncing on the subject.

 

[ianwood]

This is fascinating...

...deviation, declination, inclination, variation, hard-iron distortion, soft-iron distortion, degaussing,... anybody can be a WiKi expert so why the continual pedantic back-and-forth about this?

Sar104 is right. In this case, it is not pedantic. The distinction is important. People don't know what the compass calibration does. I would love it if everyone was a "wiki expert" including me. It would save a us from a lot of unnecessary repetition. As happens too often, people find this thread, see that it is over 100 pages long, and then skip to the end. It's the age old forum practice of posting without reading.

Not that we aren't all guilty of it from time to time but still.

 

[Andy T]

This is fascinating...

...deviation, declination, inclination, variation, hard-iron distortion, soft-iron distortion, degaussing,... anybody can be a WiKi expert so why the continual pedantic back-and-forth about this?

I use forums all the time to get expert advice on things I am clueless about. I usually do some research first but stop at getting a degree on the subject. To some my questions are stupid and they call me an idiot and others are happy to set me straight and feel good about helping me. In the end all three of us got what we wanted out of it! LOL Life is good!

 

[N017RW]

This is fascinating...

...deviation, declination, inclination, variation, hard-iron distortion, soft-iron distortion, degaussing,... anybody can be a WiKi expert so why the continual pedantic back-and-forth about this?

Sar104 is right. In this case, it is not pedantic. The distinction is important. People don't know what the compass calibration does. I would love it if everyone was a "wiki expert" including me. It would save a us from a lot of unnecessary repetition. As happens too often, people find this thread, see that it is over 100 pages long, and then skip to the end. It's the age old forum practice of posting without reading.

Not that we aren't all guilty of it from time to time but still.

You've been arguing with Pazz for a week.

How long should this campaign last?

Sorry but you can't 'fix' everybody.

 

[sar104]

This is fascinating...

...deviation, declination, inclination, variation, hard-iron distortion, soft-iron distortion, degaussing,... anybody can be a WiKi expert so why the continual pedantic back-and-forth about this?

Sar104 is right. In this case, it is not pedantic. The distinction is important. People don't know what the compass calibration does. I would love it if everyone was a "wiki expert" including me. It would save a us from a lot of unnecessary repetition. As happens too often, people find this thread, see that it is over 100 pages long, and then skip to the end. It's the age old forum practice of posting without reading.

Not that we aren't all guilty of it from time to time but still.

You've been arguing with Pazz for a week.

How long should this campaign last?

Sorry but you can't 'fix' everybody.

I guess that as long as Pazz keeps posting fundamentally incorrect information as fact then he will probably continue to be corrected. It's actually confusing to the topic under discussion to leave erroneous statements unrefuted.

 

[N017RW]

More power to ya.

But to be clear it's not really important to know the difference to use your Phantom.

DJI has specified when and how calibrate the compass and how to verify efficacy by giving you data (mod. value).

They have even 'automated' compass compensation for you so all you have to do is 'dance'.

It is interesting to some who like to learn and explore but certainly not important.

TEHO

 

[ianwood]

I guess that as long as Pazz keeps posting fundamentally incorrect information as fact then he will probably continue to be corrected. It's actually confusing to the topic under discussion to leave erroneous statements unrefuted.

This!

 

[sar104]

More power to ya.

But to be clear it's not really important to know the difference to use your Phantom.

DJI has specified when and how calibrate the compass and how to verify efficacy by giving you data (mod. value).

They have even 'automated' compass compensation for you so all you have to do is 'dance'.

It is interesting to some who like to learn and explore but certainly not important.

TEHO

In general that is probably quite true, but in the context of this specific topic these concepts are very important.

 

[HacKiwi]

So who is going to be the first to test http://www.dji.com/info/releases/dj...or-phantom-2-vision-and-phantom-2-vision-plus on declination challenged birds ? I'm interested to know how the compass issue will affect the GS function?

 

[ianwood]

So who is going to be the first to test http://www.dji.com/info/releases/dj...or-phantom-2-vision-and-phantom-2-vision-plus on declination challenged birds ? I'm interested to know how the compass issue will affect the GS function?

Already been done on the non-vision.

 

[SilentAV8R]

So who is going to be the first to test http://www.dji.com/info/releases/dj...or-phantom-2-vision-and-phantom-2-vision-plus on declination challenged birds ? I'm interested to know how the compass issue will affect the GS function?

Already been done on the non-vision.

At least three peole with Vision+ have flown the new GS app in the Orange COunty area and report great results.

 

[AnselA]

So who is going to be the first to test http://www.dji.com/info/releases/dj...or-phantom-2-vision-and-phantom-2-vision-plus on declination challenged birds ? I'm interested to know how the compass issue will affect the GS function?

Already been done on the non-vision.

At least three peole with Vision+ have flown the new GS app in the Orange COunty area and report great results.

I wonder how GS in app could fix J-hook and TBE problems?

 

[lucianopacheco]

OMG.. this will never be over.. It´s been months and when we though we were getting closer to a solution, it never happens.. Where are we now? where´s the new beta firmware? Any deadlines or we should wait forever?
I swear to god I will never buy anything again without extensive research first. And most probably never buy from DJI again.
This is just ridiculous.
Thanks everybody involved with the tests so far.

 

[SilentAV8R]

I wonder how GS in app could fix J-hook and TBE problems?

What I was reporting is that I have seen at least three people who live in an area with declination in the +12 range who have flown with the GS app and it worked nicely for them. None made any comments about J-hook, TBE, etc. All simply reported that the App works and they were happy.

 

[droneranger]

OMG.. this will never be over.. It´s been months and when we though we were getting closer to a solution, it never happens.. Where are we now? where´s the new beta firmware? Any deadlines or we should wait forever?
I swear to god I will never buy anything again without extensive research first. And most probably never buy from DJI again.
This is just ridiculous.
Thanks everybody involved with the tests so far.

I agree about the "never buy from DJI again" part. I, for one, am totally soured on them as a company, for more than just this one issue. They do indeed seem more intent on pushing out more and newer products than supporting the existing customer base. This is not atypical for many companies, but good companies do their best not to do this.

After our legislators get their act together on UAS vehicle regulations, I will decide on a follow-on AC for the Phantom. You can be sure that it won't be a DJI product.

 

[ianwood]

What I was reporting is that I have seen at least three people who live in an area with declination in the +12 range who have flown with the GS app and it worked nicely for them. None made any comments about J-hook, TBE, etc. All simply reported that the App works and they were happy.

There are a few reports of crabbing while using GS. So, it doesn't hook or TBE as it is always correcting it's position but the orientation of the Phantom may not be perfectly straight between waypoints. I don't have GS and so cannot neither confirm or deny.

 

[KassioLM]

OMG.. this will never be over.. It´s been months and when we though we were getting closer to a solution, it never happens.. Where are we now? where´s the new beta firmware? Any deadlines or we should wait forever?
I swear to god I will never buy anything again without extensive research first. And most probably never buy from DJI again.
This is just ridiculous.
Thanks everybody involved with the tests so far.

I agree about the "never buy from DJI again" part. I, for one, am totally soured on them as a company, for more than just this one issue. They do indeed seem more intent on pushing out more and newer products than supporting the existing customer base. This is not atypical for many companies, but good companies do their best not to do this.

After our legislators get their act together on UAS vehicle regulations, I will decide on a follow-on AC for the Phantom. You can be sure that it won't be a DJI product.

yesterday a just rotate the compass on my phantom to compensate the magnetic declination and solved the problem, so now i can use my phantom normaly and a buy a new landgear to change wen a firmware ben released with problem solved, so take your time guys, thanks...

 

[John Shaw]

I have a little more patience.
I think we tend to forget how high tech and cutting edge this hobby is.
With an RC airplane you move the control stick and it sends a command to the airplane and one of few control surfaces moves. PERIOD. That's all there is to it. The airplane control is low tech and piloting takes lots of skill.
I think most of us know but may not think about...
When you are hovering the Phantom the IMU keeps it level, constantly sensing any tilt and varies individual motor speeds to keep it level. The baro altimeter senses baro pressure and the motor speeds are adjusted to maintain a constant altitude. The magnetic field sensor provides heading and clockwise and counterclockwise motors are varied to hold heading. And then with six or more satellites in view the phantom uses GPS data to hold position by varying individual motor speed to tilt the phantom to counteract wind etc. Then when you want to move it your commands are combined with the above to move the craft in either normal flying, course lock, or home lock modes. There is a lot going on when you are zooming along in course lock while spinning it around in yaw. And now we are getting the GS capability, a quite a bit late, but initial reports are encouraging and it gives us a whole new capability. The fun never ends!!
So they blew it with the declination problem, maybe because that isn't a problem where they are located. It took the Drunken Sparrow to get things rolling but they are working on it. It is certainly slower than any of us would like. As many have explained, in concept there are a number of easy fixes, but in detail implementation they have to be careful depending on how they structured their software. My main complaint would be that they could have done a much better job of keeping us informed but there are language and a cultural differences for most of us.
That being said obviously each of us will decide if we want to stay in a cutting edge hobby ( I will because that's my nature ) and with every purchase we get to choose who we do business with. So with any future purchase we will compare capabilities, our experience, and costs, to make our decision. So DJI could have done better with fixes, but overall when I tell people about the capabilities of the Phantom, and even the problems we are working, IT BLOWS THEIR MINDS. Most people don't have hobbies that come even close to rivaling ours in capabilities and complexities.
I do understand that those of you who are using it for business purposes are bound to have a different, less tolerant, perspective.
My 2 cents worth.