Aircraft not connected to RC - Warranty claim

[slup]

Looking at the log, there was NO GPS at the launch site. The log also is pretty clear a homepoint was NEVER recorded during the flight, just lots of weak GPS reports. So what the log reports for Home.IsHomeRecord is false and likely from a prior flight, not the current flight.

First line in log:

No GPS signal. Aircraft unable to hover. Fly with caution (Code: 30008).; AGPS signal weak. Hovering unstable. Fly with caution (Code: 30002).; No GPS. Fly with caution.

Another pointer that the GPS was useless is this flag:

OSD.isGPSUsed

FALSE​

The GPS wasn't even being used until 8 seconds in, then the drone fought a position mismatch with the IMU for another 1.2 seconds. More evidence this was real is that the drone was slewing sideways without any control input, aka drifting.

Oh well, ignore what the log says, I guess.

To add - his screen shot showed the "no gps fly with caution" warning. No gps = no home point

So guys ... as you know, the TXT log only records from motor start to motor stop ... right?

What do you think happens if you power on your drone, let it acquire a high quality sat lock with a GPSlevel on at least 4 of 5 ... yeah, a HP is recorded. If you then carry your drone a short distance away where it loses the sat lock, yeah ... the GPSlevel drops to zero, there you start the motors for take-off & the TXT log starts recording. That TXT log will show a initial GPSlevel on zero but with a HP recorded ... just like in the OP's case. The HP was recorded before the motor started & when he took off he had a lousy GPS reception which meant that the HP wasn't refreshed during take off, that's why you don't find it in the Airdata listing.

The log isn't false at all, it shows exactly what happened ... & @eEridani , it wasn't a flight before this one ... the cell voltages was still well above 4,2V when the log started... no flight was conducted prior the one we look at. And if you mean that an even older HP was saved ... then you're wrong, with a power cycle all previous recorded HP's are gone.

If the OP have had the failsafe action on RTH instead of Land he hadn't posted here on the forum ... as the drone very likely had returned to the yellow star in the sat pic. below (the recorded HP).

And for your info ... the Airdata log is severely crippled only showing very few of the available data posts & on top of that, Airdata puts their own interpretations in out from the real TXT log... If you want to look at a log as close as possible to the real encrypted TXT you shall use the PhantomHelp csv.

(Click on the pic below to make it larger)

 

[Yorkshire_Pud]

For my own curiosity, where in the logs do you find the failsafe setting MC.failSafeAction: Land?

I don't see a reference to that in AirData. Thanks!

column 115, DK, MC.failSafeAction, Phantomhelp output csv

 

[eEridani]

So guys ... as you know, the TXT log only records from motor start to motor stop ... right?

...

The log isn't false at all, it shows exactly what happened ... & @eEridani , it wasn't a flight before this one ... the cell voltages was still well above 4,2V when the log started... no flight was conducted prior the one we look at. And if you mean that an even older HP was saved ... then you're wrong, with a power cycle all previous recorded HP's are gone.
...

If the OP had started the motors, or if the OP had powered on and carried the drone... that's a lot of hypotheticals @slup ... lol. As you have drilled many times, all we know is what the LOG says. And in the log, the home point was never set during that flight.

I find that point a bit peculiar since it is normal the home point is always updated as soon as the GPS signal reaches adequacy. That didn't happen. Perhaps this Mini SE acts different than the other drone logs I've looked at?

But, we can start motors on a drone and let it idle for a while or even lift off and land then shut them down and not do any serious battery discharge. That will constitute a prior flight, too. That's where my interpretations point. That said, we really haven't a clue where the recorded home point XY is relative to the takeoff point unless we resort to maps - and I did - they are about 7 feet apart. Within error bars for sketchy GPS, so who knows.

ps: I've found and reported errors in Mike's FlightReader / PhantomHelp math... when AirData was getting it right; so I don't really accept any of the CSV data as gospel any more. After all - this log tracing is all based on one or two peoples reverse engineering of the text file log based on the dev code DJI releases -- at least I haven't found anyone selling a log reader that is from DJI.

 

[Yorkshire_Pud]

Two plots via CsvView of the log DJIFlightRecord_2022-03-19_[18-28-38].txt

 

[slup]

... that's a lot of hypotheticals... lol. As you have drilled many times, all we know is what the LOG says. And in the log, the home point was never set during that flight.

Not at all speculative ... if you know how DJI crafts work, that's about the only way you can explain the existence of a recorded HP even though the GPSLevel was zero at motor start (log recording start) & that the HP wasn't set later in the flight.

But your angle that the log data is false ... is wildly speculative, it's nothing we have seen here in the forum so far.

I find that point a bit peculiar since it is normal the home point is always updated as soon as the GPS signal reaches adequacy. That didn't happen...

Again, the explanation is simple ... as a recorded HP existed no new was set when the GPSLevel reached 4 later in the flight.

Honestly ... I haven't a clue why you persistently continue to claim that no HP was recorded when the log clearly show that it was ... your "missing HP" hypothesis had absolutely nothing to do with this incident & the outcome.

 

[eEridani]

Not at all speculative ... if you know how DJI crafts work, that's about the only way you can explain the existence of a recorded HP even though the GPSLevel was zero at motor start (log recording start) & that the HP wasn't set later in the flight.

But your angle that the log data is false ... is wildly speculative, it's nothing we have seen here in the forum so far.


Again, the explanation is simple ... as a recorded HP existed no new was set when the GPSLevel reached 4 later in the flight.

Honestly ... I haven't a clue why you persistently continue to claim that no HP was recorded when the log clearly show that it was ... your "missing HP" hypothesis had absolutely nothing to do with this incident & the outcome.

I think you are reading more into my text than what I am saying. Clearly the log indicates the homepoint value and flagged it as true. But I am questioning the validity of how and when that was set.

Further, I am finding the lack of an inflight update concerning because in all of my personal flights, the homepoint is updated at launch, or as soon as adequate GPS signal is reached in a flight. I've had updates 25 feet and farther away from my launch point even though the drone had already set a home point.

I guess I am not as confident as you are that DJI software is flawless.

 

[Clintoops]

Really need help on this one - only had the drone 6 days - 50min flight time.

I have attached the DJI Flight record.

At a distance of ~490m i get a few sudden errors which I could not gather/read fast enough because it was flicking on and off however, it started the RTH count down and within 3 seconds the red Aircraft disconnected from RC error came up. At this point I thought it was either going to return or reconnect to the RC so I waited - neither happened.

I know for a fact my setting was set to RTH as failsafe option as this was the reason I even bought a drone.

I have tried to claim this under warranty as 1. it did not RTH 2. drone is losing being disconnected from RC even with full GPS and satellite signals?

I am new the drone flying obviously, am I right in thinking this is a technical issue with the drone?

Hey there's a learning curve to flying. I watched a lot of YouTube videos to learn all about mistakes others have made . Mini se is a small drone the controler uses wifi
Which limits range plus the moisture in trees can weaken signal to the controller.
The mini 2 has a lot stronger communication system .
When I am learning to fly in keeping it close to me so I can learn how it reacts to things around me . I have lost site of it .
Which scares me but just take hands off and figure out where it is.
By looking at the screen .
Plus I fly in an open field as not to hit things. I added prism tape to help see it . What a great little drone if used with in limitations.
Many have made mistakes not knowing they were getting in trouble. There are some apps that will help you with conditions where you will be flying . Have you taken the TRUST test great info.
Take care of yourself don't give up you can master this .

 

[NigeConnor]

It will start whatever failsafe function that is set. Pretty certain since you never had a home point set that the failsafe only had one choice: LAND.

Most tools will show the launch location as the home point, regardless of one actually being set. Since the log shows there was never a home point set after launch, which always happens if there are sufficient GPS resources available, you never had one. I might be wrong, but I trust the log.

I think rushing a launch without GPS is something most drone flyers have done at one point. But since most such launches end in some sort of disaster, we learn quickly and we don't do it again.

Here's what that Homepoint Update looks like in the log: compare this to your launch - no GPS signal. Without GPS, a home point can't be set.
View attachment 145588

It may be obvious but HOW did you get the flight information in this format? I have managed to decode the txt file but as csv which is just a massive table of numbers that I can't understand..Thanks

 

[NigeConnor]

Hi there & welcome to the forum ... even though it's due to bad circumstances.

Unfortunately DJI's investigation out from the log is accurate ... nothing points to a product failure, neither a HW or a SW.

You had a HP recorded in a place that seems to be equal to the take off spot ... so no problem there, the problem though was that your failsafe action (which gets activated if you lose the RC-AC connection) was set to "Land" according to the log. So your drone landed just there where you lost the connection.

Here below the flight path on a sat pic... red the path, green bar is the drone with a indicated yaw direction & yellow star where the HP was recorded.

View attachment 145589

And here below the relevant telemetry ... click on the chart to make it larger. The legend below the chart explain the graphs. The chart marker is placed just where the log ends so the legend have values from there. There you also have the last recorded GPS position.

As seen ... a HP was recorded but the failsafe action was "Land". Out on 1621ft straight line from the HP the connection was lost & didn't return ... you were there up on 412ft.

View attachment 145590

The reason for the disconnect was very likely that you flow your drone out of unobstructed line of sight ...

Here a pic. from where you stood ...

View attachment 145591


Trees all around you & rather close ... lets say that the trees was something like 20m high & 20m away from you. This means a 45 degree line of sight angle up to the tree tops. As you was out on 1621ft that would have required a theoretical height above HP of 1621ft in order to still have the drone within unobstructed line of sight ... you was on 412ft in reality, meaning that some connection could be maintained through the trees, but you were really pushing it & you eventually lost the connection completely.

So ... in the end your errors were a failsafe action on "Land" instead of "RTH" & a shielded maneuver position making your drone to quickly fly out of unobstructed line of sight. You have the GPS position in the chart, get a handheld GPS & go search for it ...

Hi Just wondered how you extracted the flight data and were able to present it like this...all I have been able to do is create a flight log from the .DAT file (attached) as a csv file (which won't attach and is just columns of numbers) and a txt file (attached) which is not very user friendly either..Thanks for your help!!

 

[Kilrah]

CsvView Downloads

 

[slup]

It may be obvious but HOW did you get the flight information in this format?...

Hi Just wondered how you extracted the flight data and were able to present it like this...

I recommend that you read below linked post regarding flight logs, it covers most important thing's like what kind of logs that exist, how to retrieve them, what the different logs contain, how to read them & what tools that can be used ...

Mavic Flight Log Retrieval and Analysis Guide

 

[EricJT]

Thanks for the reply - makes sense.

Seems like I need a pilot degree to operate this thing in future. Thought this product is for everyone already, guess not I lasted 1 flight outside my living room.

My sympathies for your first ever outdoor flight.

I have been flying DJI AC for about 10 years. Before I ever took off, I read the manual(s) and multiple forums, and watched many YouTube videos from experienced pilots. That provided me with the fundamentals of flying safely.

It is not unlike a new driver studying and understanding a car's control mechanisms and safety features.

Don't let your experience turn you off this hobby....patiently learning about the AC's features and abilities is the first step followed by close in flying in a wide open space. After that, as your abilities and skills increase, you will gain self-confidence.

 

[DJIMINISE123]

Guys thank everyone for the info and input.... I've learnt so much if not for this experience.....

You gave me confidence that it landed and the GPS coordinates were spot on on where it landed!!!!

After a 40min hike in dense bushland...... it was sitting on the ground for the last 7 days.... haha!! Wet but overall clean condition, have it drying in rice tonight and will give it a spin tomorrow!

THANK YOU FOR THE ASSISTANCE EVERYONE!!

P.s DJI support is great. Addressed all my concerns. Offered 30% off a replacement which was approx $227AUD as courtesy

 

[BossBob]

Guys thank everyone for the info and input.... I've learnt so much if not for this experience.....

You gave me confidence that it landed and the GPS coordinates were spot on on where it landed!!!!

After a 40min hike in dense bushland...... it was sitting on the ground for the last 7 days.... haha!! Wet but overall clean condition, have it drying in rice tonight and will give it a spin tomorrow!

THANK YOU FOR THE ASSISTANCE EVERYONE!!

P.s DJI support is great. Addressed all my concerns. Offered 30% off a replacement which was approx $227AUD as courtesy

Don’t try flying it after only leaving in rice overnight! Rice is good for pudding or paella, it doesn’t dry out electronics.
Your drone will need a couple of days in a warm dry place, preferably with silica gel desiccant bags around it and good airflow around it. The battery needs to be out and I wouldn’t ever trust it for a flight again. As it was only rain you might get lucky, but don’t be hasty about starting up the drone. Short circuits caused by retained moisture are harder to fix than physical damage to propellers or bodywork.
Well done on finding the drone, now don’t ride your luck too far.

 

[eEridani]

Don’t try flying it after only leaving in rice overnight! Rice is good for pudding or paella, it doesn’t dry out electronics.
Your drone will need a couple of days in a warm dry place, preferably with silica gel desiccant bags around it and good airflow around it. The battery needs to be out and I wouldn’t ever trust it for a flight again. As it was only rain you might get lucky, but don’t be hasty about starting up the drone. Short circuits caused by retained moisture are harder to fix than physical damage to propellers or bodywork.
Well done on finding the drone, now don’t ride your luck too far.

Rice is better than nothing, and has been tested by experts and reported as working comparably to desiccants at moisture removal. While rice has dust, so do desiccants, so caution is warranted in both cases when used around sensitive equipment. Note: I just posted in another thread a link to US National Institute of Health paper comparing rice to desiccants for use drying hearing aides.

But, overnight isn't enough for something that has been outdoors in the wet for days.