Hi all,
I was using my Mini 3 Pro yesterday something weird happened. I had a good connection to RC with 29 sats connected, calm weather, clear skies flying over the sea by the coast in Cornwall, UK. I momentarily flew around a cliff and it lost all connection and the screen froze. I've been in this situation before and it's never gone from 100% to nothing immediately. It didn't report it was RTH. I wondered if a seagul had got it at this point!
However it eventually did RTH - what was different was it didn't reconnect to the RC once it was closer, even though I was right next to it, it had to complete the landing. I turned everything off and on and again and it seems OK but this combination of things hasn't happened before.
I looked at the log file for the moment it happened and got these 2 lines:

GPS signal weak. Switched to Attitude mode. Aircraft unable to hover. Fly with caution.; IAircraft in Attitude mode. Unable to hover. Fly with caution (Code: 30004).; Attitude mode. Fly with caution.
Compass or GPS signal weak. Changed to Attitude mode.; IAircraft in Attitude mode. Unable to hover. Fly with caution (Code: 30004).


GPS was not weak - it reports 29 satellites on the same line.

The log file then shows it hovers in place for 45 seconds and then the log stops. It doesn't record any of the return flight.

Does this sound familiar to anyone?
Thanks, Tom

Hi Tom

Helpfull to analyse is your flightlog, use > https://www.phantomhelp.com/LogViewer/Upload/
Post the uploaded link on here.

Guess you were lucky....for some reason your drone into ATTI mode, in ATTI no return to home ofcourse! Without RC input it will hover and drift away on the wind.
But as it did return in RTH your drone started to use the satellites again...

What do you mean with "incorrect ATTI mode" in your header ?

cheers
JJB

Hi JJB,
Here's the log: https://www.phantomhelp.com/LogViewer/5DSQKQ78TCC65NUN2G28/
Incorrect ATTI mode as it appears to have good GPS lock at that point.
I haven't really looked at logs much before, am I right to say there is no log stored on the drone itself?

mrtomuk Posted at 12-12 01:00
Hi JJB,
Here's the log: https://www.phantomhelp.com/LogViewer/5DSQKQ78TCC65NUN2G28/
Incorrect ATTI mode as it appears to have good GPS lock at that point.

Hi Tom,

Only 1 record in the log shows ATTI, at 4m56.2.
Few warnings  that time:

• GPS signal weak. Switched to Attitude mode. Aircraft unable to hover. Fly with caution.
• Aircraft in Attitude mode. Unable to hover. Fly with caution
• Compass or GPS signal weak. Changed to Attitude mode.
• Aircraft in Attitude mode. Unable to hover. Fly with caution
  

GPS looks oke, so my guess is a spurious compass error. Compass errors can make the drone goes into ATTI mode.

After that the log shows your Mini3Pro steady in Hover at 102 meters baro height, no RC input.
So why did it flew back in a RTH ? batt level 75% last record.

As the last 45 secs were recorded without RC input, guess your screen was frozen ect  but still in contact RC<>Drone.
Did you press the RTH button on the RC ?  or swiched off the RC ?  that`s way a RTH is initiated.

Indeed, logs are stored on the RC (with screen) or on the mobile device.

Question ; when you switched to Sport mode, do you remember if the mode swictch on the RC was in the left position and not the middle N position?

cheers
JJB

Thanks JJB,
After the 45 seconds, the screen was still frozen and didn't come back to life even once the drone was right next to me landing.
I didn't press the RTH button and pretty sure I didn't turn off the RC. I had to turn turn the RC off and force close the DJI Fly app on the phone to clear this. I did this once it had landed.
Sorry I can't remember what position the switch was in after being in sport mode. Probably still Sport as I was getting to a position to take a pic at the time.
I tried the drone again yesterday and everything was fine, so not sure whether to put it down as a one off or dig further. It's been 100% reliable up to this.

mrtomuk Posted at 12-12 03:02
Thanks JJB,
After the 45 seconds, the screen was still frozen and didn't come back to life even once the drone was right next to me landing.
I didn't press the RTH button and pretty sure I didn't turn off the RC. I had to turn turn the RC off and force close the DJI Fly app on the phone to clear this. I did this once it had landed.

Hi Tom,

Oke, so we don`t know how the RTH was initiated.

Not by low battery, not by press on the RTH button and not by switching off the RC.
Well, i did fly back to home happily.

If the next flights are fine, than just fly the drone  and trust the RTH  ;-)

cheers
JJB

JJB, do you keep a record of these threads or incidents where the controller/phone will not reconnect after a disconnection?
If so can you check whether or not the screen device was Apple or Android?
I think the use of the phrase "force close" is associated with the use of an Apple device and I have a recollection of that phrase being used in another thread, possibly in connection with a failure to reconnect after a disconnection.
I am wondering if this failure to reconnect might be a problem when using Apple devices. The "app type' column in the csv is empty.
Or could it be an App version problem e.g. 1.8,  .... though I suspect not.
Or controller type?

Just in case it's useful, in this case I was using an Android phone and the app froze completely. I had to force close DJI Fly.
I use a dedicated phone with the RC, it doesn't run anything else, has no sim card in and gets data from my main phone. I like this set up as calls, texts, alerts don't interrupt the phone on the RC.

Sean-bumble-bee Posted at 12-12 05:01
JJB, do you keep a record of these threads or incidents where the controller/phone will not reconnect after a disconnection?
If so can you check whether or not the screen device was Apple or Android?
I think the use of the phrase "force close" is associated with the use of an Apple device and I have a recollection of that phrase being used in another thread, possibly in connection with a failure to reconnect after a disconnection.

Hi,

No, i do not log this kind of disconnects.

I always use my dedicated Android devices, must say never had an issue with the FlyApp on Android.
When i switch off the flyapp for tests, always been able to reconnect again.
cheers
JJB

JJB* Posted at 12-12 06:37
Hi,

No, i do not log this kind of disconnects.

Ahh ok and thanks.

@MrTomUK, re
''..... in this case I was using an Android phone and the app froze completely. I had to force close DJI Fly. ''

What do you mean by force close?

The only way I have ever closed an app on android is to 'reduce it' (press the rectangle to the left of the home button) and then swipe the reduced image to one side or other of the screen.

I am sad to report it happened again yesterday.
It was all going well until the it lost connection, the screen remained black and white. It eventually RTH.
Here's the log: https://www.phantomhelp.com/LogViewer/7IGFPEV7Z005ABIL74Q7/

Regarding closing the crashed app, I do the same right button, then click the trash can icon to close all open apps.
I am going to try using another phone as a last chance.

Here's the screen at point it lost connection:

Your screen capture is telling you that the phone is NOT connected to the controller. This means the controller still has command of the drone. The screen capture is NOT telling you that the drone is disconnected from the controller, the warning message for that is different.

If the same thing happened in the first flight an RTH would not have happened ( because the controller and drone were still connected ) until the low battery RTH kicked in. If the phone remained disconnected from the controller then you would NOT have regained a live camera view nor telemetry BUT you would have been able to control the drone.

I would check the controller to phone cable and the socket in the phone

One other point I have just noticed and I do not know if this is applicable to the Mini 3 but, you were quite high and quite close to the the home point, I assume the controller was close to the home point.
With a Mini 1 that combination often results in a weak control signal or a lost control signal, I am guessing because the antennae are not really designed for near vertical signals. The Mini 2 seems better, whether that is due to a redesign of the antenne or a better controller or something else I do not know.
I think the Mini 3 uses the Mini 2 controller but it might be something you want to bear in mind.

mrtomuk Posted at 12-17 08:49
I am sad to report it happened again yesterday.
It was all going well until the it lost connection, the screen remained black and white. It eventually RTH.
Here's the log: https://www.phantomhelp.com/LogViewer/7IGFPEV7Z005ABIL74Q7/

The only thing i can see but it might not be as it looks and that is the heading that the drone icon is showing on the map doesn't match the logs, i.e. at startup the drone is pointing North in the log but on the map its pointing South.

Bashy Posted at 12-17 18:27
The only thing i can see but it might not be as it looks and that is the heading that the drone icon is showing on the map doesn't match the logs, i.e. at startup the drone is pointing North in the log but on the map its pointing South.

At startup the recorded flight data indicates the drone was pointing to 160°.
This is exactly what is shown in the map window of the Phantomhelp log viewer.

mrtomuk Posted at 12-17 08:49
I am sad to report it happened again yesterday.
It was all going well until the it lost connection, the screen remained black and white. It eventually RTH.
Here's the log: https://www.phantomhelp.com/LogViewer/7IGFPEV7Z005ABIL74Q7/

I am going to try using another phone as a last chance.
The phone isn't the problem.
The cable is the most likely cause of the issue.
That's the simplest and cheapest thing to check.

mrtomuk Posted at 12-17 08:49
I am sad to report it happened again yesterday.
It was all going well until the it lost connection, the screen remained black and white. It eventually RTH.
Here's the log: https://www.phantomhelp.com/LogViewer/7IGFPEV7Z005ABIL74Q7/

Hi,

Something else again in your log : ATTI mode for just 1 record.
See my chart of your data.
Nothing to do with loosing connection between RC and mobile device, but should not be in the log.

cheers
JJB

Labroides Posted at 12-17 23:51
At startup the recorded flight data indicates the drone was pointing to 160°.
This is exactly what is shown in the map window of the Phantomhelp log viewer.

Thats not what i am seeing, i see near as damn it, North.

Bashy Posted at 12-18 05:01
Thats not what i am seeing, i see near as damn it, North.

[view_image]

Thats not what i am seeing, i see near as damn it, North.
There's not a single number in what you posted that indicates the drone's heading.
But the highlighted column here shows the drone's heading from startup.

You should leave data analysis to those who know what they are doing.

What is the HD column in my image or have i misread that?
Some of us are trying to learn, you didn't know everything when you were learning.

What program produced that 'spreadsheet'?

Bashy Posted at 12-18 07:49
What is the HD column in my image or have i misread that?

HD column = HomeDistance....(so distance from fly position to HP)

Sean-bumble-bee Posted at 12-18 08:37
What program produced that 'spreadsheet'?

Spreadsheet post #18 is from FRAP.

JJB* Posted at 12-18 12:18
HD column = HomeDistance....(so distance from fly position to HP)

Ah, thank you for your patience, I thought it was Heading.
Looking at it again, it should have been obvious what with the blooming decimal point and the other column with HDGº lol

Bashy Posted at 12-18 19:47
Ah, thank you for your patience, I thought it was Heading.
Looking at it again, it should have been obvious what with the blooming decimal point and the other column with HDGº lol

its my pleasure to help, patience is what we need in this fast hectic world, keeps the blood pressure low!

Hey guys i just wanna add in here after having the exact same problem right now, hearts racing as i thought i lost it, same Mini 3 pro drone but i have the pro controller, and it did the same thing, on the coast, no wind, 85m high 800m away, and it just switched on me into ATTI mode for no reason. Luckily i pressed home button asap and it came home with 20% bat after having 40% ekkk. feeling it could be a bug.

mifarr Posted at 12-19 10:35
Hey guys i just wanna add in here after having the exact same problem right now, hearts racing as i thought i lost it, same Mini 3 pro drone but i have the pro controller, and it did the same thing, on the coast, no wind, 85m high 800m away, and it just switched on me into ATTI mode for no reason. Luckily i pressed home button asap and it came home with 20% bat after having 40% ekkk. feeling it could be a bug.

Can you post the flight log, as per post #2 ?

mifarr Posted at 12-19 10:35
Hey guys i just wanna add in here after having the exact same problem right now, hearts racing as i thought i lost it, same Mini 3 pro drone but i have the pro controller, and it did the same thing, on the coast, no wind, 85m high 800m away, and it just switched on me into ATTI mode for no reason. Luckily i pressed home button asap and it came home with 20% bat after having 40% ekkk. feeling it could be a bug.

If RTH brought your drone home, it wasn't in Atti Mode.
If it was in Atti Mode, all you would have had to do was fly the drone back for yourself.