AntDX316 Posted at 1-30 19:17
What would happen?

Depends upon - whether your internal speakers are shielded**.  And where on speaker's cabinet you placed drone in relation to speaker(s) inside.   
Assuming worse case, your drone would ended up with it's own magnetic field, which would fool drone's internal compass(es).

**Old speakers designed to be used near TVs having CRT for screen - speakers had magnetic shielding to prevent CRT from being effected by speakers magnets.

Dirty Bird Posted at 1-30 20:46
Your aircraft will likely present you with immediate compass errors from exposure to the strong magnetic field produced by the speaker.  Depending on how powerful the field, clearing the condition may prove difficult.

It would be like having a magnet on something metal and it holding the charge after a while.  Excellent for picking up small screws.

Dirty Bird Posted at 1-30 20:46
Your aircraft will likely present you with immediate compass errors from exposure to the strong magnetic field produced by the speaker.  Depending on how powerful the field, clearing the condition may prove difficult.

I learned this by carelessly sitting my Vision+ carry case on a box containing a big new Sony boombox.  I realized it later before I flew so I was prepared.  Sure enough, constant unresolvable compass errors were encountered next time I tried to fly.  I degaussed the compass multiple times before I finally got it cleared & even ordered a replacement compass module just in case.

Good you brought up speaker magnetizing a drone.

It might be a possible explanation as to what caused OP's drone to have compass problems, even though takeoff was from dirt path.  Whereas we normally see compass problems when people have tried to take off from concrete with rebar, dock piers with steel, metal car hoods or roofs, patio decks with metal railing, etc.

Possibility is OP had a metal bracelet, watch, or ring on.  Possibly magnetized, when powering drone up resulting in compass being way off.

One other thought.  There was no source of magnetic interference.  The compass error was result of bad compass data (hardware failure) or (software bug).

Hopefully, DJI Service and Repair will provide informative diagnosis...  But I won't hold my breath.

HedgeTrimmer Posted at 1-30 23:13
Good you brought up speaker magnetizing a drone.

It might be a possible explanation as to what caused OP's drone to have compass problems, even though takeoff was from dirt path.  Whereas we normally see compass problems when people have tried to take off from concrete with rebar, dock piers with steel, metal car hoods or roofs, patio decks with metal railing, etc.

It might be a possible explanation as to what caused OP's drone to have compass problems, even though takeoff was from dirt path.  Whereas we normally see compass problems when people have tried to take off from concrete with rebar, dock piers with steel, metal car hoods or roofs, patio decks with metal railing, etc.

Possibility is OP had a metal bracelet, watch, or ring on.  Possibly magnetized, when powering drone up resulting in compass being way off.
One other thought.  There was no source of magnetic interference.  The compass error was result of bad compass data (hardware failure) or (software bug).

It's no help to have people who don't know making guesses.
Your contributions to this thread have been one guess after another.
You are continuing on that path.
It's obvious that you don't understand what a yaw error is and how it happens.

Hopefully, DJI Service and Repair will provide informative diagnosis...  But I won't hold my breath.
Whether you understand it or not, this incident was a clear and simple case of a yaw error.
There's no need to keep digging for implausible explanations.

HedgeTrimmer Posted at 1-30 20:21
Believe it has been discussed before here.

Something like 15 or more degrees of compass deviation from actual is enough to cause flight problems when drone clears a magnetic field and compass jumped to actual, resulting in conflict with IMU.

Hi HedgeTrimmer,

The Attitude Indicator (in compass mode)  in the GO 4 app and the Aircraft Position indicator uses compass data from a mobile device as well.  And they do not always work great (understatement)

But if you check your drone heading in the map view, than the info wich heading the arrow is pointing is only form the drone compass. So easy drone compass check on the ground, as the map view is always North up orientated. Align your drone along the road or river ect   and check in the map view the arrow heading.
Something else ;
Have seen many may files and the compass and yaw values are in the logs.
Initialisation of the IMU means, afaik, to set a yaw reference value in the IMU wich is compass derived during powering up the drone.
What is see is that for the MM the 2 values can differ from each other but they change in same value when yawing manually the craft.
Ref yaw needed ofcourse to know wich corrections to be made when yaw is disturbed, acc meters for the intensity of correction.
For other crafts than MM i see little variations in the 2 values after powering up.

But when i had my MM i was curious if my MM showed the same, sometime large, variations in the 2 values.
Surprise, they were better than most of the other seen MM logs. Uh ???

'Problem'with the power button on the MA and MM is that it is located on the bottem of the craft.
I always put my crafts on the ground, one finger under and switch to ON.
Mayby keeping the drone upside down, movnig around etc, switching on does has effect on the initialising of and feeding the IMU with a yaw ref signal.

cheers
JJB

Labroides Posted at 1-30 23:43
It might be a possible explanation as to what caused OP's drone to have compass problems, even though takeoff was from dirt path.  Whereas we normally see compass problems when people have tried to take off from concrete with rebar, dock piers with steel, metal car hoods or roofs, patio decks with metal railing, etc.

Possibility is OP had a metal bracelet, watch, or ring on.  Possibly magnetized, when powering drone up resulting in compass being way off.

this incident was a clear and simple case of a yaw error.

Could You please explain for begginers what is yaw error and how to avoid it?
Is the remedy in "checking the orientation of the drone and comparing to what the directional indicator in the app shows" and power up the AC not too close to the bridge in this case?

virtual Posted at 1-31 01:57
this incident was a clear and simple case of a yaw error.

Could You please explain for begginers what is yaw error and how to avoid it?

A yaw error is complicated to explain but it comes from powering up the drone within the magnetic field of some steel or a live electric cable.
The drone initialises and sets its gyro sensors but they will have an incorrect orientation.
Think of it as their north isn't really north.

When the drone gets away from the magnetic field and turns, the compass data suggests the drone has turned one way but there is a conflict with the gyro data and the drone thinks it has moved and tries to correct.
The more it corrects, the further and faster it moves away, usually on a curved path and sometimes faster than the drone's specs.

Occasionally the difference between the compass and gyros is only small and the drone can be recovered.
But it's usually quite serious and ends badly.

To avoid, don't launch from reinforced concrete or close to steel objects.
It's not simple to say how far because it depends on distance and size of the steel object.
It could be caused by a nail or bolt in a wooden deck just an inch or two from the compass or a car a metre away.

To be absolutely certain, before flying check that the drone icon in your directional indicator is correctly oriented in respect to the compass.
ie.  If the drone on the ground is pointing north, the drone icon should be pointing north.

The drone then moves in the direction it thinks will

It’s a pity that something like this gets drawn out so much and it helps no one and only confuses things for others, after log was put up in post 12 it was clear what happened and we’ve seen it many times before and I went on to explain exactly how this happens and why in post 15, but for the last two years I have been trying to explain this but was met with the same BS , it can’t be this it can’t be that, dji should offer information diagnosis etc etc, fact is there were two very good guys here who offered perfect diagnosis and others who also checked agreed, but then the BS comes in it can’t be this it can’t be that, but never being able to tell us what it can be, more BS about gps which was frankly ridiculous and again only serves to confuse.

This is actually somebody’s drone he put up his logs for analysis, not to be tossed around by one person because he’s to stubborn to accept that he might be wrong, but worse than that has no credible answers to offer OP only to continue to drag out the thread with absolutely no solution.

We have all we need in our drones to show and tell us if something is wrong , we don’t require extra apps or major changes in the app that comes with the drone, and instead of all the BS maybe time would be best spent helping OP to see the signs so it doesn’t happen again.

Every case for the last two years like this that has come up here the same person with what I can only call complete waffle has tried to prove that this fault was anything but compass magnetic or yaw problem, hopefully now he might get the message, this is not rocket science.

virtual Posted at 1-31 01:57
this incident was a clear and simple case of a yaw error.

Could You please explain for begginers what is yaw error and how to avoid it?

Check out post 15, and here’s an exercise that takes less than one minute will help you not to get into this kind of trouble .


1/ Never calibrate Compass unless prompted to.

2/ start AC leave until you receive enough gps lock ,

3/ if you get Compass interference turn off AC and move to another location,
without interference.

4/ In bottom left hand corner on your map you will see small red triangle, check to make sure that this triangle is pointing in the same direction (heading) as your AC, this will show good compass on the ground.

Raise AC to height of 8ft
Hover for 20 seconds
Fly forward 2ft
Backward 2ft
Left 2ft
Right 2ft
Up 2ft
Down 2ft
Yaw left
Yaw right
Each time returning to hover position
If you have a good horizontal each time, you will then know you have good GPS good IMU and good Compass, and your ready to fly.

This exercise takes less than 1/2 minutes and is worthwhile doing before every flight,

Labroides Posted at 1-31 02:59
A yaw error is complicated to explain but it comes from powering up the drone within the magnetic field of some steel or a live electric cable.
The drone initialises and sets its gyro sensors but they will have an incorrect orientation.
Think of it as their north isn't really north.

Good to know, thank You! Pre-flight check of directional indicator would be good practice (according to surroundings)...

hallmark007 Posted at 1-31 03:10
Check out post 15, and here’s an exercise that takes less than one minute will help you not to get into this kind of trouble .

Hi hallmark,

Good check list as always to inform others.

But about point 4/    in the go 4 app the arrow in that little compass view does only show the same heading as the actual drone if the mobile device is correct calibrated
You can check the offset to North to check but that might be confusing.
Lot of users have problem with their compass devices .

I find it easier to check heading of my drone in the map view as the map is always North orientated and the arrow gets its info only from the drone.
No mobile device (incorrect) compass data is used for that.

Aircraft orientation indicator in the FlyApp is even worse to show the correct heading, so for me is the check only in the map view.

cheers
JJB

JJB* Posted at 1-31 07:49
Hi hallmark,

Good check list as always to inform others.

It is the map I’m talking about bottom left corner, not bottom Centre , and I did say MAP .

hallmark007 Posted at 1-31 03:10
Check out post 15, and here’s an exercise that takes less than one minute will help you not to get into this kind of trouble .

Good to know to calibrate the Compass just when I get a message prompt, since I thought it's better to calibrate it each time I'm at another location.

Thanks for that, still a lot to learn.

Mizzu Posted at 1-31 08:47
Good to know to calibrate the Compass just when I get a message prompt, since I thought it's better to calibrate it each time I'm at another location.

Thanks for that, still a lot to learn.

Usually moving distance it will prompt . Hope it helps .

Just FYI I've been flying approx. 135 km away in 2 days and no calibration requested, drained all 3 baterries without issue.

virtual Posted at 1-31 09:58
Just FYI I've been flying approx. 135 km away in 2 days and no calibration requested, drained all 3 baterries without issue.

Good for you, wish mine operated the sam if I travel 50km I’m asked to calibrate, and really there is never a need to calibrate unless you add or take something to your craft.
Fly safe .

From OP's description, he did the exercise described under #4, of "Raise AC to height of 8ft" etc.

The exercise was fruitless in that it did not show any problems with AC.  Might have led to false confidence.

Mizzu Posted at 1-31 08:47
Good to know to calibrate the Compass just when I get a message prompt, since I thought it's better to calibrate it each time I'm at another location.

Thanks for that, still a lot to learn.

As you have experienced you can calibrate compass even if you don't get a message about needing too.
However, when you do calibrate compass, you must follow DJI's steps for calibration.  Especially ensuring there are not sources of magnetic interference within 10-meters of drone.  That includes anything on person holding drone doing compass calibrations.

Labroides Posted at 1-30 23:43
It might be a possible explanation as to what caused OP's drone to have compass problems, even though takeoff was from dirt path.  Whereas we normally see compass problems when people have tried to take off from concrete with rebar, dock piers with steel, metal car hoods or roofs, patio decks with metal railing, etc.

Possibility is OP had a metal bracelet, watch, or ring on.  Possibly magnetized, when powering drone up resulting in compass being way off.

It's no help to have people like yourself proclaim it was a Yaw error due to a source of magnetic interference at startup.  Then put down any attempt to try to figure out what source of magnetic interefrence was in attempt to prevent other pilots from suffering similar.

Here is what I do understand.

Nobody has identified why compass was incorrect at power-up.  Whether it was due magnetic interference below ground, being to close to bridge, something OP was wearing, compass being completely out of calibration, faulty compass hardware, or software bug.


There has been no explaination as to why before drone did it's flyaway there was a burst of "GPS Position NoMatch" error messages.  Indicating drone is getting conflicting location or bad data as to location.  Is "GPS Position NoMatch" a false message?   Message indicating drone is about to do a fly away as a result of Yaw error induced by compass error?

hallmark007 Posted at 1-31 03:07
It’s a pity that something like this gets drawn out so much and it helps no one and only confuses things for others, after log was put up in post 12 it was clear what happened and we’ve seen it many times before and I went on to explain exactly how this happens and why in post 15, but for the last two years I have been trying to explain this but was met with the same BS , it can’t be this it can’t be that, dji should offer information diagnosis etc etc, fact is there were two very good guys here who offered perfect diagnosis and others who also checked agreed, but then the BS comes in it can’t be this it can’t be that, but never being able to tell us what it can be, more BS about gps which was frankly ridiculous and again only serves to confuse.

This is actually somebody’s drone he put up his logs for analysis, not to be tossed around by one person because he’s to stubborn to accept that he might be wrong, but worse than that has no credible answers to offer OP only to continue to drag out the thread with absolutely no solution.

It’s a pity that something like this gets drawn out because one forum member continues to act like he is god.  Putting down others, while continuing to fluff his ego.
A forum member who continues to push his own ideas while trashing others.  Karma has come.
A forum member with such a god complex as to create multi-accounts to up-vote his own posts and pat himself on back, and vote down others.
A forum member who puts words in other people's mouth so he can Troll-n-Trash person.
A forum member who "post" braggs about being right, but absolutely can not admit when he was shown to be wrong.  Even when he has done some himself.

quarter-turn_25-degrees

So here is to you forum god!

Your only here to confuse people and try boost your stupid ego, give it a rest, your wrong and no matter what you make up or who you bring into this it's not going to make it right, this is about helping people, it's not about boosting your ridiculous ego .
Again more complete BS, if log was checked it would have been clear no exercise was done neither at 8 feet or 80ft, so we are again faced with the usual BS instead of admitting totally out of his league. Once again there is only one person singing in the choir in tune, let’s face it, all your capable of is guessing and it helps no one.

HedgeTrimmer Posted at 1-31 11:21
From OP's description, he did the exercise described under #4, of "Raise AC to height of 8ft" etc.

The exercise was fruitless in that it did not show any problems with AC.  Might have led to false confidence.

But he did not check the compass heading in the map view before takeoff.

If he had checked this he had noticed that the heading arrow was not pointing as the actual heading.
Arow pointing different heading than the actual heading > don`t go flying!

And do we ever really know what is the cause of a compass/  yaw errror??  sometimes they are there   out of the blue flying minutes high in the sky.....

cheers
JJB

hedgetrimmer is on the wine again .

JJB* Posted at 1-31 12:18
But he did not check the compass heading in the map view before takeoff.

If he had checked this he had noticed that the heading arrow was not pointing as the actual heading.

Thanks JJB for you polite and professional response.

Dirty Bird Posted at 1-30 11:40
Immediately take manual control & get the bird on the ground.  Power off, move to a new starting location, restart the aircraft.  Often times you don't have to move far.  If the interference is caused by metal in concrete, a bridge, or pier, you can usually just launch from your hand & that's enough distance to alleviate the issue.

If you wanted to be extra cautious you could add a compass to your kit & test the launch spot by placing it on your intended launch spot & comparing the pointer to magnetic north.

Then I don't understand what happened here: hasn't the pilot reacted to the fly away? To my understanding, the drone was irresponsive to commands

hallmark007 Posted at 1-30 11:18
That’s what the pilot is for, there are checks you can do before flying including what you intend to do and what measures you intend to take if something might go wrong, it’s probably not just a coincidence that the vast amount of users don’t lose their drones.
This crash was caused by simple interference picked up on the ground, it could have been avoided and I posted in an earlier post how it happens and how to avoid it .

You mean turning around and see if compass is following?
That's easy to do ok.
But what about interferences you encounter during the fly?
Is it possible to take off without any problem and pick during the fly an interference that dooms the drone to crash (because the controls are irresponsive)?

hallmark007 Posted at 1-31 10:41
Good for you, wish mine operated the sam if I travel 50km I’m asked to calibrate, and really there is never a need to calibrate unless you add or take something to your craft.
Fly safe .

I thought I would have to calibrate, even watched YT video guides prior the trip, but no request, no warnings, no problems. Maybe very similar altitude of both places helped?

" or maybe a bridge, if there were any around..."

Apologies if this has been covered, but G**gle has loads of pictures of this gorgeous bridge, a feature of which is the array of cable stays going from head height to 122 metres. It seems very likely that at around 1:24.4 at least a couple of these spun the AC round and gave it a good knock.

Plus the source of illumination must involve electricity somewhere.

https://commons.wikimedia.org/wiki/File:Most-Redzinski-z-mostu-Milenijnego.jpg

The story goes on. Today I received email from service with information about sending replacement to me. Replacement will be covered under warranty. No info about concluded reason of the crash. So for me the story has a happy endind, though I can not give you official reason of the failure. Thanks for all support and informations. I hope next week I will be flying again.

Ewa i Piotr Posted at 2-4 14:35
The story goes on. Today I received email from service with information about sending replacement to me. Replacement will be covered under warranty. No info about concluded reason of the crash. So for me the story has a happy endind, though I can not give you official reason of the failure. Thanks for all support and informations. I hope next week I will be flying again.

Wish DJI had given official reason as to cause, and replacement being covered under warranty.

Regardless, it is great news it is being covered.   

Thank you for reporting back!  

Ewa i Piotr Posted at 2-4 14:35
The story goes on. Today I received email from service with information about sending replacement to me. Replacement will be covered under warranty. No info about concluded reason of the crash. So for me the story has a happy endind, though I can not give you official reason of the failure. Thanks for all support and informations. I hope next week I will be flying again.

As I said in post 15 it’s likely dji would replace you drone, so I’m pleased for you, safe flying .

HedgeTrimmer Posted at 2-4 14:47
Wish DJI had given official reason as to cause, and replacement being covered under warranty.

Regardless, it is great news it is being covered.   

Like you, DJI ageed to replace my first Mini after it dropped into a river.  I appreciated that.  The replacement drone behaved the same way but has been much better since putting on new props.  I hope you have good luck with your replacement.

Ewa i Piotr Posted at 2-4 14:35
The story goes on. Today I received email from service with information about sending replacement to me. Replacement will be covered under warranty. No info about concluded reason of the crash. So for me the story has a happy endind, though I can not give you official reason of the failure. Thanks for all support and informations. I hope next week I will be flying again.

I’m glad DJI is making you happy with a new Mini.
So far I have been enjoying mine and have not experienced any of the issues described in these forums. Reading the threads from people who have asked for help is discouraging. It seems there is always a conflict that erupts and a few people get into a “ My drone is bigger than your drone “ contest.
If I happen to have a problem with my Mini, I won’t be asking for help here.

Hi Jmynes, today I am also happy, as I got a new Mini. I found this community pretty helpful, I got a lot of information. And even if not all of them were correct explanations of what happened, it was useful. Another lesson for me is to get liability insurance, as it doesn't matter how catious I am - error can happen and then I will be legally responsible for a crash.

And to close the case - this is how my Mini looked after the crash. What I got today is called "repaired", though I don't think it was really a repair.

edit: As I can not upload an image, below is the link to a photo of crashed Mini, if anyone likes horror stories ;)
Crashed Mini

Ewa i Piotr Posted at 2-7 13:59
Hi Jmynes, today I am also happy, as I got a new Mini. I found this community pretty helpful, I got a lot of information. And even if not all of them were correct explanations of what happened, it was useful. Another lesson for me is to get liability insurance, as it doesn't matter how catious I am - error can happen and then I will be legally responsible for a crash.

And to close the case - this is how my Mini looked after the crash. What I got today is called "repaired", though I don't think it was really a repair.

Mini was badly beaten RIP mini, dji only do new or refurbished replacements, your drone will go back to Shenzhen and be stripped for parts, but the board looked good and I’m certain this is the most costly part.

I wish you happy and safe flying .

There was a spate of Mavic Pro flyaways a year or so ago after a series of firmware updates. It is a possibility this is a similar thing. See other recent posts for mini.
People without experience in writing complex software don't understand the reason for software failure. Perhaps because they only see the device and think it is all mechanical.
They should wonder why their laptop needs an update when they haven't had a problem and others have. It is because certain conditions the software tests for result in a silly answer or a glitch.
I remember being caught out with a flyaway when I tried to take a video of a sunrise, before the island airport opened.
Picture the scene, I only wore a dressing gown, slippers and the look of eager expectation a droner has when taking a shot.
The drone climbed to 50 metres and held position for about a minute. After that it drifted backwards at a slow rate and even the forward stick had no effect.
After checking settings and readings, I had drifted over rising ground and towards the airport. Reducing altitude wasn't an option now, because I would have lost signal. Anyway, I looked down with the camera to see what I was over. It was a group of houses. Beyond that, it would continue to drift over open fields and sea. It was going to miss the airport grounds.
I decided to reduce altitude while I still had a chance and then it would have to take its chances.
Down it went and then I lost control signal, but, the camera feed was still running.
This was the nightmare scene. A house roof raced into view. The drone was going to hit the ridge (Apex) and there was nothing I could do.
I think God stepped in, but more likely RTH, because with inches before impact, the drone shot up and then I got the RTH warning and regained full control.
For those who believe it was due to wind, this dosen't stack up, because it returned to the origional position, directly overhead and then I cancelled the RTH. I returned to 50 m (from 30 m) and it was stable.
All this time, the camera had been running.
This is why I do not update the software now, after returning to 01.03.07 and using NLD firmware mods and software.
When you fly your drone, there is always the possibility it will crash, so make certain it can do no harm.
I won't fly unless conditions and my surroundings allow a safe flight if the worst should happen.

AlansDronePics Posted at 2-10 02:00
There was a spate of Mavic Pro flyaways a year or so ago after a series of firmware updates. It is a possibility this is a similar thing. See other recent posts for mini.
People without experience in writing complex software don't understand the reason for software failure. Perhaps because they only see the device and think it is all mechanical.
They should wonder why their laptop needs an update when they haven't had a problem and others have. It is because certain conditions the software tests for result in a silly answer or a glitch.

For those who believe it was due to wind, this dosen't stack up, because it returned to the origional position, directly overhead and then I cancelled the RTH.

All your story says is that you had a flight incident that you didn't understand.
It proves nothing about nothing and it's hard to see how it's related to updating firmware.
Did you have anyone look into the flight data to find the real explanation?

Your ideas about firmware updates, show a similar lack of interest in facts.