Compass error, gps loss, Imu error due to no fly zone?
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fansb181213c
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hallmark007 Posted at 2017-10-25 09:41
Why would a compass error disable GPS?
Orientation (compass data) and position (GPS data) are different but related.
When the Spark is moving and getting position information from the GPS that tells the Spark that it is travelling in a different direction from what it's getting from compass data, The Spark programming can't work with the data conflict.

I hadn't calibrated the compass for months, and the last time I did was actually not far from where I was flying when the problem occurred. I have probably done 100 flights since and never any warnings.
The only difference between that flight and the previous one was I switched to sports mode not long before it went nuts.
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fansb181213c Posted at 2017-10-25 11:14
I hadn't calibrated the compass for months, and the last time I did was actually not far from where I was flying when the problem occurred. I have probably done 100 flights since and never any warnings.
The only difference between that flight and the previous one was I switched to sports mode not long before it went nuts.

The Mavic Pro had a documented issue in Sports Mode with magnetic interference they fixed in a firmware upgrade around the beginning of the year.  Unfortunately the documented fix for it was to fail over to the other compass in the Mavic since the Mavic has redundant hardware in it.  I say unfortunately because the Spark does not have redundancy if the issue is of a similar nature.
2017-10-25
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Kloo Gee Posted at 2017-10-25 11:21
The Mavic Pro had a documented issue in Sports Mode with magnetic interference they fixed in a firmware upgrade around the beginning of the year.  Unfortunately the documented fix for it was to fail over to the other compass in the Mavic since the Mavic has redundant hardware in it.  I say unfortunately because the Spark does not have redundancy if the issue is of a similar nature.

When we discussed the procedure for getting home on GPS alone, people asked me - if you say it's supposed to work, why hadn't DJI put something like that into other models before?
I guess that's the answer. The redundant hardware.
In Spark they don't have that hardware redundancy, but they can do better with what they've got.
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djiuser_Kf4iPA3 Posted at 2017-10-25 11:44
When we discussed the procedure for getting home on GPS alone, people asked me - if you say it's supposed to work, why hadn't DJI put something like that into other models before?
I guess that's the answer. The redundant hardware.
In Spark they don't have that hardware redundancy, but they can do better with what they've got.

I still have PTSD (not something I should joke about) from that conversation!

I had mentioned the redundancy decision for the Spark as well as the known Mavic issue in the last 2 paragraphs of this post in that thread:  https://forum.dji.com/forum.php? ... &fromuid=825250
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Kloo Gee Posted at 2017-10-25 12:08
I still have PTSD (not something I should joke about) from that conversation!

I had mentioned the redundancy decision for the Spark as well as the known Mavic issue in the last 2 paragraphs of this post in that thread:  https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=114937&pid=990935&fromuid=825250

Nothing can make fly-aways or what are being seen as flw-always a thing of the past or an impossibility.

What dual GPS, dual IMU and dual Magnetometer (compass) can give you is redundancy so that potentially things are more reliable since if one fails you have a back up.
Although dual GPS is not really to do with preventing fly-aways, it is simply used for better positional accuracy.
Now for the price point DJI cannot give true redundancy which requires three of each module. That way a comparison can be made between each of the three and if one starts giving differing data to the other two it can be switched out the system by the flight controller and all is well. With only having two of each sensor, if one gives some strange data there is no real way of knowing which of the two is feeding the erroneous information to the flight controller. So, no, dual modules DOES NOT mean no more fly-aways. However, DJI would have written in algorithms to the flight controller that will look at the data coming from the accelerometers and gyros whilst comparing the attitude of the aircraft with correlation to stick input. If the two do not agree, the erroneous IMU would be ignored.

As I have said before we can’t ignore the fact that there would almost certainly be a cost factor in having dual compass and IMU it would also mean that spark would be a bigger aircraft.

It also should be said I read more of these so called fly-aways due to compass problems happening with Mavic than spark, so they do happen even with dual redundancy models, and yes I do know that there are many more Mavics out there than sparks.
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hallmark007 Posted at 2017-10-25 10:22
Yeah do put your video up might help understand what happens.



Here is the video, with the flight log overlaid to see what was going on and what the Spark was doing.  Evidently, there was a strong magnetic interference in the square concrete/steel building nearby which caused the compass errors.  

I was lucky in that this did not occur when the drone was out of my line of sight, and that I have been flying model airplanes for several years before buying the Spark and am able to control the AC without having to think about inputs.   

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TexasAerials Posted at 2017-10-25 13:04
https://www.youtube.com/watch?v=JV2iKEyy3sw

Here is the video, with the flight log overlaid to see what was going on and what the Spark was doing.  Evidently, there was a strong magnetic interference in the square concrete/steel building nearby which caused the compass errors.  

You did a great job controlling AC , the most important thing about flying Atti mode is to make very positive stick movements and you certainly did that, obviously your experience helped, new users could learn a lot from this.
I do think the area you were flying in may have had effected your compass but good job safely landing your AC.
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TexasAerials Posted at 2017-10-25 13:04
https://www.youtube.com/watch?v=JV2iKEyy3sw

Here is the video, with the flight log overlaid to see what was going on and what the Spark was doing.  Evidently, there was a strong magnetic interference in the square concrete/steel building nearby which caused the compass errors.  

Great job controlling your Spark in ATTI mode!  I'm looking to get a cheapo, dumb, non-GPS quad very soon so I can practice for whenever it inevitably will happen to me.
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Kloo Gee Posted at 2017-10-25 17:15
Great job controlling your Spark in ATTI mode!  I'm looking to get a cheapo, dumb, non-GPS quad very soon so I can practice for whenever it inevitably will happen to me.

Check out rcsaylors on YT, they are always testing all manner of budget/beginner drones.
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TexasAerials Posted at 2017-10-25 19:50
Check out rcsaylors on YT, they are always testing all manner of budget/beginner drones.

Yep, I've seen some of their videos as well.  Thanks!
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hallmark007 Posted at 2017-10-25 12:59
Nothing can make fly-aways or what are being seen as flw-always a thing of the past or an impossibility.

What dual GPS, dual IMU and dual Magnetometer (compass) can give you is redundancy so that potentially things are more reliable since if one fails you have a back up.

hallmark007,

I'm sure this particular explanation was pertinent to the conversation when you originally wrote it 2 years ago for a different website forum.  (At least I hope it was you that wrote it and not someone else. )

https://mavicpilots.com/threads/ ... laim.452/#post-5663

I'm not sure why you felt it necessary to track it down from 2 years ago and copy it here word-for-word.  I really don't think it is pertinent to the post of mine that you have replied to and quoted.  I have not suggested that the Spark be made to have redundant systems.  You are not the only person smart enough to figure out that more hardware equals higher price point for the consumer.  Also, I have not suggested that it is possible to make a completely foolproof system that will prevent all fly away situations.

I have pointed out the fact that the Spark does not have redundant hardware that other DJI aircraft contain.  However, I have not suggested that the Spark should be made redundant nor that redundancy is a magic bullet that will fix all evils.  I did suggest a software based solution (in the other thread on this forum)  to a given problem that has led to lost and crashed aircraft given a very basic and clearly defined set of assumptions that also compared the engineering costs to implement vs. the ongoing continuous support costs, PR issues, and lost sales due to lost and crashed aircraft.

I'm also not quite convinced that your description of the redundant components that are found in the Mavic Pro and the Phantom 4 is actually how DJI has implemented it.  If you have DJI reference material to back up those descriptions, I would be happy to see them and learn.  However, the Mavic compass error issue that I have referenced has indications from the DJI tech referencing "main" and "backup" to go along with a further description making it seem like only 1 system is being used at a time and switching to the other one when an error occurs with the one currently being used.  
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Kloo Gee Posted at 2017-10-25 22:35
hallmark007,

I'm sure this particular explanation was pertinent to the conversation when you originally wrote it 2 years ago for a different website forum.  (At least I hope it was you that wrote it and not someone else. )

I think my post was pertaining to this thread , and it was meant to carry on from what Texas was saying regarding what happened.
Yes of course if there is a software fix for this problem then it should be looked into and I’m sure it will, anything that can make AC safer is worth looking into.
I think Texas made a very honest admission of what occurred during his flight from takeoff to landing. And it showed quite clearly that not preparing your AC properly and flying in unsuitable environment is more likely to cause this problem than a firmware/software problem.
I think you will have seen very few of these cases occurring over the last few weeks, so those who were convinced by others that this was a problem with software/firmware issues may have got this wrong.

I believe that it is better to try to help others with what they have to work with, and yes I have watched your videos and you have done a great job in helping others with the same.
What happens in these situations is when a “(fly-away)” happens there are many around who will try to create hysteria, and many end up thinking that they have a defective unit with some almost afraid to fly their AC.
I tend to take a pragmatic view, so finding out exactly what happened to see if it could be avoided with what we already have and how to help with what we already have, but I find when trying to do this you are almost pi**ing against the wind, simply because it’s much easier to blame the AC the manufacturer etc.
So what happens is when we see these “fly-aways “ we have those who immediately jump in and say this is a real problem with the AC and it needs to be sorted ASAP , when in reality there is no real problem with the AC , but with those using the AC and how they use it.
It is my belief that most of these “fly-aways “ could be avoided with what we have at present.
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hallmark007 Posted at 2017-10-25 12:59
Nothing can make fly-aways or what are being seen as flw-always a thing of the past or an impossibility.

What dual GPS, dual IMU and dual Magnetometer (compass) can give you is redundancy so that potentially things are more reliable since if one fails you have a back up.

Neither Kloo Gee nor I ever said our procedures (his is actually better than mine) will prevent all cases of flyaways. They can, however, reduce flyaways that originate from one case - compass errors, which today illogically also cause the throwing away of GPS data. We never claimed they can fix EVERYTHING.
On top of it, our procedures can help the pilots locate their drones much more easily in case they don't make it all the way home.

Neither Kloo Gee nor I ever said we need dual-whatever for our procedures to work. In fact, I think our procedures are needed BECAUSE the dual hardware isn't there, and BECAUSE we know it's unrealistic to add any hardware over the existing one.

Nor do we claim that even dual hardware would have fixed everything.

Regarding the Mavic cases you mention - are they before or after the fix Kloo Gee mentioned? (and yes, you have to factor in that Mavics are much more commonplace than Sparks, and they've also been flying longer).
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Kloo Gee Posted at 2017-10-25 12:08
I still have PTSD (not something I should joke about) from that conversation!

I had mentioned the redundancy decision for the Spark as well as the known Mavic issue in the last 2 paragraphs of this post in that thread:  https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=114937&pid=990935&fromuid=825250


Being a heretic is never easy.......
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djiuser_Kf4iPA3 Posted at 2017-10-26 04:06
Neither Kloo Gee nor I ever said our procedures (his is actually better than mine) will prevent all cases of flyaways. They can, however, reduce flyaways that originate from one case - compass errors, which today illogically also cause the throwing away of GPS data. We never claimed they can fix EVERYTHING.
On top of it, our procedures can help the pilots locate their drones much more easily in case they don't make it all the way home.


Again I don’t think you are getting my point, what I’m saying and I will say it again we don’t have a defective craft we are all aware or should be aware of how it works and how to operate it. It comes with what it says on the tin. So taking it from there it is my opinion that it is better to help those having problems as it is now , not trying to create hysteria continually saying that there is a problem with firmware/ software causing the problem, if this was the case then we would be seeing a heck of a lot more problems resulting from this particular issue. And the reality is we have seen one case in the last three weeks.
What you and kloo Gee are putting forward is something that has not been tried or tested by both of you, but rather a white paper from two people with similar backgrounds in this type of technology and that’s fine, but so far it’s not real.
We have seen case above with Texas it shows clearly by his actions and his own words the cause of his difficulties right through to the safe return of his AC. this is a real situation and this in my opinion is what users need help with now. They don’t need continual speculation that there is a firmware/software problem with their AC because this is not the case.
Yes you or dji can develop a safer cheaper redundancy for their present set up that I’m sure that would welcomed by all, but until we see  something like this rolled out we have to accept what we have now and try to help those who are having problems with it now and not be trying to lead them up a dark alley into believing there is a defect or problem with their AC that reduces them to being scared to fly.
And if the day comes when these AC can fly only using gps then we can help them better understand how to fly using only gps, I’m dealing with the present your dealing with the future.
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hallmark007 Posted at 2017-10-26 05:20
Again I don’t think you are getting my point, what I’m saying and I will say it again we don’t have a defective craft we are all aware or should be aware of how it works and how to operate it. It comes with what it says on the tin. So taking it from there it is my opinion that it is better to help those having problems as it is now , not trying to create hysteria continually saying that there is a problem with firmware/ software causing the problem, if this was the case then we would be seeing a heck of a lot more problems resulting from this particular issue. And the reality is we have seen one case in the last three weeks.
What you and kloo Gee are putting forward is something that has not been tried or tested by both of you, but rather a white paper from two people with similar backgrounds in this type of technology and that’s fine, but so far it’s not real.
We have seen case above with Texas it shows clearly by his actions and his own words the cause of his difficulties right through to the safe return of his AC. this is a real situation and this in my opinion is what users need help with now. They don’t need continual speculation that there is a firmware/software problem with their AC because this is not the case.

Very well, the present can be summed up as "learn to fly ATTI you SOBs, or kiss your drone goodbye because compass loss means all navigation is deliberately rendered kaput".
That's the present, everyone agrees so. If you lose compass, and you're not Charles Lindbergh, you are in deep s**t.
That's the way things are today. I never said otherwise. Doesn't mean we all have to accept that as the gospel for all times to come.

That's the present. And Kloo Gee and I are offering a future, a better future and a doable future with the hardware that's already there. Yes, it's an idea; any progress starts with an idea. I don't have the means or the equipment to build it and test it; but I know how the involved technologies work, so I know that right now GPS is utilized in an illogical manner in case of compass loss.
And since this is after all a firmware addition and not a hardware one, I see no sense in just letting it go. Dropping GPS data that can be used to save your craft even if you're not an ace pilot - doesn't make sense.

How is pointning out a missing feature causing hysteria? you got it all backwards. It's the underutilization of the technology that casues loss of confidence if you're not accustomed to ATTI. If the technology is used to its fullest potential in case of compass loss, it would boost people's confidence.

And I believe Texas was a lot more reserved than you. He said that lucky for him (his words), his incident happened right after takeoff and the craft was not too far off. He also happens to be a very experienced model pilot. Not all of us are, and if the existing hardware can be utilized better to aid the less experienced or less proficient - I see no reason to rule it out right off the bat.
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djiuser_Kf4iPA3 Posted at 2017-10-26 06:48
Very well, the present can be summed up as "learn to fly ATTI you SOBs, or kiss your drone goodbye because compass loss means all navigation is deliberately rendered kaput".
That's the present, everyone agrees so. If you lose compass, and you're not Charles Lindbergh, you are in deep s**t.
That's the way things are today. I never said otherwise. Doesn't mean we all have to accept that as the gospel for all times to come.

LEARN TO FLY YOU SOB’s.
I’m sure that wasn’t dji’s intention with spark, as I tried to explain if you manage your craft correctly and fly in the right environments then it is highly unlikely that the problem will occur so for now it remains the responsibility of the pilot and rightly so to take the necessary precautions to see this matter doesn’t arise.
In fact it is more likely you will lose gps on its own than have compass problems which will result in having to fly Atti mode whether it be in your system or present system. So yes it’s a good idea to learn Atti mode if you want to fly drones.
Your not offering any future to anyone, you wrote something down which has never been tested or used in any drone that I know of, but for now those who have bought these drones want to fly them now the vast majority of people are and will continue to do so, and those who are having some problems want help with them now.
HOW IS POINTING OUT A MISSING FEATURE CAUSING HYSTERIA.
There is no missing feature so to say something is missing is just not true. All dji drones operate on the same systems all aircraft from the big to the small and none of them ever had this so called feature.
You have also been banging on about a problem with compass firmware being wrong and again this took somebody else to show you your observation was wrong,
And yes Texas was lucky as he said but he knew what to do because he had experience of flying model AC, his compass problem happened on the ground or very close to him this is something he eluded to been a mistake on his part which could have been avoided.
There is no secret in learning to fly Atti mode it does require some practice and I would recommend to those who wish to learn to buy a cheap quad and get some practice.
What your so called fix for bad compass and not loosing gps, won’t help those who lose gps (Which cannot be avoided) and still have no choice but to fly in Atti mode, so yes learning to fly Atti is very important for all drone flyers.
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ciesnik Posted at 2017-7-29 23:36
i have performed the update just 2 days ago to the latest firmware on all batteries, controller, spark and app. it was the latest firmware.

i experienced the exact same thing multipe times - first a NFZ warning, then weak GPS signal followed by Exit P-GPS errors resulting in ATTI mode. i still maintain 0.0600 is flaky...but, like hallmark007 said,  ATTI mode practice is clearly imperative!
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DJI Thor Posted at 2017-10-25 01:10
Just to verify, did you see all those yaw error, speed error, compass error and then weak GPS messages on DJI GO 4 app? If there is compass error, please try to calibrate the compass after cooling the drone down, and if there is weak GPS signal, please also try to change another place.

the last time it happened to me flying my brand new replacement AC, i got tons of yaw errors
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Kloo Gee Posted at 2017-10-25 17:15
Great job controlling your Spark in ATTI mode!  I'm looking to get a cheapo, dumb, non-GPS quad very soon so I can practice for whenever it inevitably will happen to me.

same here - it only makes sense!
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TexasAerials Posted at 2017-10-25 13:04
https://www.youtube.com/watch?v=JV2iKEyy3sw

Here is the video, with the flight log overlaid to see what was going on and what the Spark was doing.  Evidently, there was a strong magnetic interference in the square concrete/steel building nearby which caused the compass errors.  

The building that you were near seems to me like it might be a pump house or something along those lines and maybe around 12-15 ft high.  Does that seem accurate?  Did you hear anything running inside of it like a generator or pumps?  

Also, at the point in the video you lost your GPS signal and started getting the errors on screen (0:37), you were at 36ft high.  So you probably would have been around 20ft above it.  Does that sound roughly accurate based on your recollection?  Once it went to ATTI mode, it looks like you gained another 10-15ft of altitude and stayed there for around 20 seconds (still in ATTI mode) while gathering control and bringing it back for a landing.

Sorry for all the questions.  Just trying to learn as much as I can.  If the environment was responsible for the behavior, then trying to understand what that environment looked like so that we can learn from it and help others (including myself) avoid a similar situation.

Thanks in advance for sharing your experience!
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djiuser_Kf4iPA3 Posted at 2017-10-26 06:48
Very well, the present can be summed up as "learn to fly ATTI you SOBs, or kiss your drone goodbye because compass loss means all navigation is deliberately rendered kaput".
That's the present, everyone agrees so. If you lose compass, and you're not Charles Lindbergh, you are in deep s**t.
That's the way things are today. I never said otherwise. Doesn't mean we all have to accept that as the gospel for all times to come.

Where your comment about dropping GPS data that "could save your craft" goes wrong is that you assume that the GPS data is accurate all the time.  I have seen many GPS tracks from handheld GPS units that track within a foot up until they get near a cell tower or microwave antenna, and the location accuracy goes from tens of inches to tens of feet.  I've seen GPS interference to a lesser extent from just tree cover, cause the spark to wander 6ft to the left or right.  If the GPS data is suspect, the spark is right to ignore it, or it could cause crashes rather than prevent them.  

Now, I don't think that is a good enough reason for the Go4 app to stop updating the crafts position on the screen, because that information along with the video feed would be very helpful in determining the location of the aircraft and getting it back home.  
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TexasAerials Posted at 2017-10-26 09:34
Where your comment about dropping GPS data that "could save your craft" goes wrong is that you assume that the GPS data is accurate all the time.  I have seen many GPS tracks from handheld GPS units that track within a foot up until they get near a cell tower or microwave antenna, and the location accuracy goes from tens of inches to tens of feet.  I've seen GPS interference to a lesser extent from just tree cover, cause the spark to wander 6ft to the left or right.  If the GPS data is suspect, the spark is right to ignore it, or it could cause crashes rather than prevent them.  

Now, I don't think that is a good enough reason for the Go4 app to stop updating the crafts position on the screen, because that information along with the video feed would be very helpful in determining the location of the aircraft and getting it back home.

In my case despite of exit gps after compas error , gps data and kml file extracted from dat was good but ignored for 22 seconds by spark .https://forum.dji.com/forum.php? ... 9616&fromuid=982278 .
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TexasAerials Posted at 2017-10-26 09:34
Where your comment about dropping GPS data that "could save your craft" goes wrong is that you assume that the GPS data is accurate all the time.  I have seen many GPS tracks from handheld GPS units that track within a foot up until they get near a cell tower or microwave antenna, and the location accuracy goes from tens of inches to tens of feet.  I've seen GPS interference to a lesser extent from just tree cover, cause the spark to wander 6ft to the left or right.  If the GPS data is suspect, the spark is right to ignore it, or it could cause crashes rather than prevent them.  

Now, I don't think that is a good enough reason for the Go4 app to stop updating the crafts position on the screen, because that information along with the video feed would be very helpful in determining the location of the aircraft and getting it back home.

i get what you said, but think of it this way: these days there's GPS even in low-end smartphones, and they  have to work in much tougher conditions than a drone does, typically. They work in cities, at ground level, surrounded by buildings, power lines, metal structures, transmitting antennas of all sorts. They see a smaller portion of the sky (hence, fewer satellites) than a drone in mid-air, which typically flies in an open environment, does. And yet they are able to acquire and maintain GPS, or re-acquire it quickly when the lose it, with excellent credibility and accuracy.
If Spark's GPS is so much more susceptible than a low-end smartphone's GPS, despite operating in typically better environmental conditions, then there are other questions that DJI need to be asked about the design of the GPS. That's another matter, though.
But I highly doubt that's the case. GPS in general is much more robust to magnetic interference than a compass, especially with the redundancy of satellites (if its firmware is smart enough).

But let's suppose for the sake of argument that what you say is right, and Spark's GPS is super susceptible to anything near it.
With our procedures, which I don't know whether you got to read in full, the drone first rises to its RTH altitude, which is enough to clear most obstacles (that's what RTH altitude is there for). And once up, Spark is always on the move, in order to find its bearing based on GPS alone. If something causes the super susceptible GPS to err, Spark will eventually move and the error will dissipate. Even with drift, it will be able to converge, after some zigzaging, to the right direction.

I disagree that it would cause more crashes or lost drones than ATTI mode. Most Spark users, seems to me, are not experienced pilots and rely on the technology to aid them as much as they can, especially if a system fails.
And like you said yourself, not everyone is lucky enough to have it happen to them right after takeoff. If it happens on the edge of your line of sight or the edge of your controller range, you are in trouble. A little wind drift away from you, pushing it out of range, and even the most proficient pilot would lose the drone.
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Kloo Gee Posted at 2017-10-26 09:20
The building that you were near seems to me like it might be a pump house or something along those lines and maybe around 12-15 ft high.  Does that seem accurate?  Did you hear anything running inside of it like a generator or pumps?  

Also, at the point in the video you lost your GPS signal and started getting the errors on screen (0:37), you were at 36ft high.  So you probably would have been around 20ft above it.  Does that sound roughly accurate based on your recollection?  Once it went to ATTI mode, it looks like you gained another 10-15ft of altitude and stayed there for around 20 seconds (still in ATTI mode) while gathering control and bringing it back for a landing.

Yeah, the building was likely a pumphouse for the underpass (I was trying to film the canal going over the motorway) but it did not sound like anything was running inside at the time.  It did have a big steel door about the size of a garage door on one side, but I figured I was ok because it was 20-25ft from where I took off.  If you look at the position on the map compared with the video, the spark thinks it is pointing towards the pump house while in the video it is actually to the right.  It seems that once I clear the height of the pump house is when the spark realizes that something is not right between the compass and GPS data and goes into ATTI mode.  

The reason for the immediate climb after the error and ATTI mode is that the AC immediately started drifting on the wind towards the trees, and not being sure that I would have enough control authority to fight back into the wind, I climbed to try to get above them and give myself more room to land further downwind.  It did try to get back into GPS mode a few times but was still unsuccessful, but it did go into OPTI mode as soon as it was able and settled down once that happened.   

Now that I've written all of that, I'm thinking that I'll make a separate post with the video and the above explanation in order to help others mentally prepare themselves for when/if this happens to them.  
2017-10-26
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TexasAerials Posted at 2017-10-26 10:31
Yeah, the building was likely a pumphouse for the underpass (I was trying to film the canal going over the motorway) but it did not sound like anything was running inside at the time.  It did have a big steel door about the size of a garage door on one side, but I figured I was ok because it was 20-25ft from where I took off.  If you look at the position on the map compared with the video, the spark thinks it is pointing towards the pump house while in the video it is actually to the right.  It seems that once I clear the height of the pump house is when the spark realizes that something is not right between the compass and GPS data and goes into ATTI mode.  

The reason for the immediate climb after the error and ATTI mode is that the AC immediately started drifting on the wind towards the trees, and not being sure that I would have enough control authority to fight back into the wind, I climbed to try to get above them and give myself more room to land further downwind.  It did try to get back into GPS mode a few times but was still unsuccessful, but it did go into OPTI mode as soon as it was able and settled down once that happened.   

That is good stuff!  Thanks very much for sharing the details!   

The behavior sounds very much like what I experienced not too long after I got my Spark.  However, I wasn't as experienced as you at the time and crashed my Spark.  I was flying very close to a metal windmill when my experience occurred.  In my situation, like yours, the compass was also pointing in one direction when the AC was actually facing a different direction.

I think it would be great to make a separate post so that it is easily found by people not wanting to wade through this one.
2017-10-26
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Kloo Gee Posted at 2017-10-26 10:52
That is good stuff!  Thanks very much for sharing the details!   

The behavior sounds very much like what I experienced not too long after I got my Spark.  However, I wasn't as experienced as you at the time and crashed my Spark.  I was flying very close to a metal windmill when my experience occurred.  In my situation, like yours, the compass was also pointing in one direction when the AC was actually facing a different direction.

Done.  Now, back to work, lol.  
2017-10-26
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TexasAerials Posted at 2017-10-26 11:03
Done.  Now, back to work, lol.

I've been obsessively reading this forum for enough time to find it interesting that there is a big number of people complaining about gps/compass/atti issues since the latest firmware, but yet the user "hallmark" stoically persists in creating imaginary user errors... So far this was just a gut feeling, but as soon as Dji offered me a 100% coupon for a new spark, after I had the exact same problem in Iceland, I realised my gut feeling was not wrong...
2017-10-26
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Jose Ramos Posted at 2017-10-26 15:21
I've been obsessively reading this forum for enough time to find it interesting that there is a big number of people complaining about gps/compass/atti issues since the latest firmware, but yet the user "hallmark" stoically persists in creating imaginary user errors... So far this was just a gut feeling, but as soon as Dji offered me a 100% coupon for a new spark, after I had the exact same problem in Iceland, I realised my gut feeling was not wrong...

First off they are not imaginary user errors and if you read this thread you would see that two of the cases were before latest firmware, and Texas who you are replying to believes he was responsible for the issues he had regarding his problems.
So I’m not sure why you think that all compass gps problems were caused by latest firmware update if you have something to say to me you can PM me or answer directly to my post.
2017-10-26
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fansb181213c Posted at 2017-10-25 02:46
1st error at 68m weak gps signal, followed by compass error, exit gp-gps mode, warning inflight imu encounters heading exception, more weak gps errors as the flight progresses. All these show when I replay the flight in DJI Go4. I had 18 satellites showing and full signal strength in green, it then blanked out, still showing 18 sats but the bars just in grey. I attempted to fly back visually and after 2 minutes the GPS locked again. This was the second flight that morning from the same location, the first about 10min with no errors at all.
Quite scary as I was at the beach and could have easily lost it if it had flown out to sea.
Really shattered my confidence and put up my heart rate quite a lot ;-).

Please try to test in another location, calibrate the IMU and compass first. If the GPS frequently behaves the same in places where should have fine GPS signal, you might need to contact our support support@dji.com and have a check on the data.
2017-10-26
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hallmark007 Posted at 2017-10-26 15:36
First off they are not imaginary user errors and if you read this thread you would see that two of the cases were before latest firmware, and Texas who you are replying to believes he was responsible for the issues he had regarding his problems.
So I’m not sure why you think that all compass gps problems were caused by latest firmware update if you have something to say to me you can PM me or answer directly to my post.

I don't think that I "caused" the magnetic interference on my flight, and there was never a compass interference warning before takeoff.  I would say that I understand the cause of the magnetic interference  that triggered the error in flight.  
2017-10-27
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TexasAerials Posted at 2017-10-27 05:15
I don't think that I "caused" the magnetic interference on my flight, and there was never a compass interference warning before takeoff.  I would say that I understand the cause of the magnetic interference  that triggered the error in flight.

I understand that I don’t think you caused magnetic interference, but you did realize what had caused the interference in the area you were flying in.
2017-10-27
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DJI Thor Posted at 2017-10-26 22:48
Please try to test in another location, calibrate the IMU and compass first. If the GPS frequently behaves the same in places where should have fine GPS signal, you might need to contact our support  and have a check on the data.

Is it normal for the compass to show a slight variations all the time when the AC is sitting on the ground?
Mine will drift constantly between 0 and around 30, however, if I hold the AC near metal it immediately jumps into the hundreds and the interference bar moves up.
2017-10-27
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Rawsome Posted at 2017-7-30 15:09
Ciesnik sorry for your loss.
I dislike how the NFZ error is being brushed under the table though, it seems to be a common culprit that leads to more trouble when flying.

that is absolutely correct - the NFZ warning was a common theme among every time i experienced weak GPS or compass errors leading to ATTI mode mid-flight
2017-10-27
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this is what happens when buggy firmware ruins a perfectly good flight while operating a brand new replacement AC:

video


flight record


every one of the classic symptoms are present: random compass/weak GPS/Exit P-GPS/IMU Exception errors & an NFZ warning resulting in ATTI mode. please remember that during almost 50 straight flights before 0.0600, i never got any of these errors w/my first Spark - not once. my conclusion: pilot error/negligence (or hardware failure, in my case) aren't always to blame...
2017-10-28
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jcwconsulting Posted at 2017-10-28 10:28
this is what happens when buggy firmware ruins a perfectly good flight while operating a brand new replacement AC:

video

There were some strange movements just after 32 sec to 40 sec did you make these moves or was it compass problem reason I ask is maybe you picked up interference from small pier you took off from.
2017-10-28
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hallmark007 Posted at 2017-10-28 11:14
There were some strange movements just after 32 sec to 40 sec did you make these moves or was it compass problem reason I ask is maybe you picked up interference from small pier you took off from.

the crosswinds were gusty @ that point (10-20mph), so the AC's horizontal path does seem a bit shaky. to answer your other question, it's hard to tell if the dock had any metal frame reinforcements or pilings underneath, which also occured to me might well contribute to compass interference.
2017-10-28
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fansb181213c Posted at 2017-10-27 14:26
Is it normal for the compass to show a slight variations all the time when the AC is sitting on the ground?
Mine will drift constantly between 0 and around 30, however, if I hold the AC near metal it immediately jumps into the hundreds and the interference bar moves up.

If it is a green bar, then it is normal. I get 77 and green bar now in my drone and all work well.
2017-10-30
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jcwconsulting Posted at 2017-10-28 10:28
this is what happens when buggy firmware ruins a perfectly good flight while operating a brand new replacement AC:

video

After watched more cases of compass error from different pilots  , it seem to me the error time period last about 22-25 seconds .Can you post the .dat file ?
2017-10-30
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hallmark007 Posted at 2017-10-28 11:14
There were some strange movements just after 32 sec to 40 sec did you make these moves or was it compass problem reason I ask is maybe you picked up interference from small pier you took off from.

so to follow up on all this, it does appear to have been metal interference - probably f/the dock. Sparkomatic appears to be functioning normally now...
2017-11-13
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