Smart controller disconected during flight

[paul242]

I thought the disconnect message related to your mobile device and the SC, not the SC and the drone?

 

[Gindra]

I've been flying with a SC for a year now. Have taken it out 2 miles over the ocean but more routinely just fly under one mile away. It's been rock solid. Only time I had a disconnect was when I stupidly forgot to reorient the antennae when I brought the drone directly overhead. As soon as I reoriented properly and restarted the app all was good.

I've never regretted the decision to get this controller. Unless you got a bad SC somehow, it seems unlikely that the problem was the SC itself.

It would be really interesting to see the flight log so it can be determined exactly what happened during this flight. No need for buyer's remorse yet .

 

[Paul2660]

Just wanted to add from 1 year experience with SC. Back to the post with the drawings. I have found that I get considerably better range (based on signal strength bars), when I hold the SC with antennae straight up. This is harder to do for long periods of time since your arms are up. Signal just seems to be stronger that way.

Also have had the issue of not re-orientation of the antennae out flat when Drone is directly overhead and low signal strength warning.

Paul C

 

[Muddiver]

I was flying my M2Z with SC when it disconnected. I was on my 3rd battery of the day. I was 11m 52s into the flight and the M2Z was 769ft down range at 200ft alt. The AC battery was at 59%, the SC was at 52%. I had clear VLOS with nothing in between me and the AC, I was on a ball field. SC antennas where oriented correctly. I’ve flown at this location a lot in the past and never have been an issue. I looked down at the SC and it says “disconnected” and DJI Go4 froze and says “program will exit”. I looked at my M2Z and it’s just hovering and I have no control of it. I have it set that if it losses connection that it should RTH but it just hovered. DJI GO4 restarted and it reconnected to the AC and I regained control and brought it back. I’ve had the M2Z & SC for 6 months and never had any issues. The only thing different I did was that day I changed the video cashe from 2GB to 4GB which now I think what may have caused my issue since apparently the SC only has 4GB of RAM.

Am I correct in my thinking of what happened or is there something else going on?

 

[jzilla80]

I was flying my M2Z with SC when it disconnected. I was on my 3rd battery of the day. I was 11m 52s into the flight and the M2Z was 769ft down range at 200ft alt. The AC battery was at 59%, the SC was at 52%. I had clear VLOS with nothing in between me and the AC, I was on a ball field. SC antennas where oriented correctly. I’ve flown at this location a lot in the past and never have been an issue. I looked down at the SC and it says “disconnected” and DJI Go4 froze and says “program will exit”. I looked at my M2Z and it’s just hovering and I have no control of it. I have it set that if it losses connection that it should RTH but it just hovered. DJI GO4 restarted and it reconnected to the AC and I regained control and brought it back. I’ve had the M2Z & SC for 6 months and never had any issues. The only thing different I did was that day I changed the video cashe from 2GB to 4GB which now I think what may have caused my issue since apparently the SC only has 4GB of RAM.

Am I correct in my thinking of what happened or is there something else going on?

The first matter is your adjustment from 2 to 4GB. That is not relating to RAM, but how large of a storage allocation, within your SC, for cached video.
Thats not likely what caused of your issue...

Q: What SC firmware version you were running?
.530 or the latest .650? ( SC menu, near the bottom. Not in GO4 menu)

Ive been using the SC since about 30d after release. Ive done plenty of testing running CPU & RAM usage monitors. When the AC is off, and you run GO4, CPU runs at about 30%, add 10-20% for screen recording. As soon as the M2 is powered up and links to SC, that avg jumps to 95% with peaks at 100%.

That consistent usage had causes some screen lag and studder for me when using hyperlapse and other intelligent modes, but no disconnect relating to heavy CPU usage. (Had a few from signal loss but thats different!)
These results were before the .650 update (running .530 for the most part)

It was only after the .650 fw update, that I had similiar disconnects on 2 separate occasions, both within 1km.

IMO, DJI did some internal optimization changes, and as a side effect, introduced a few odd issues that were seeing, on occasion. What Ive noticed, post .650, is that the CPU usage is lower, on average, than the .530 and before... I wish I knew what they did but I think the changes were significant, internally (ie: coding), since you never get a performance boost like that without new disadvantages.

Your issue sounds slightly different than mine, in that you say you had no stick input and your AC hovered, instead of initiating RTH (as you had RTH upon disconnect selected, in the settings). Also, that your Go4 app restarted automatically, without your input.

This leads me to believe that while you had no stick input, I dont think you had a full disconnect, but rather your app blocked input for a moment while it self-reset and reacquired signal link.

While the strangeness of the event is enough to make any of us panic, It did fix your issue, all on its own.

My disconnect left the app screen black/white but I still had stick input, and my app never restarted. Upon flying in and landing, I powered down and swapped batteries, restarted AC, but still had no fpv on SC. I had to reset the GO4 app manually, and that did the trick. Flew another mission no problem.

Summary:
While we paid a hefty amount on these SC, its a sad fact that specs wise, the SC is on par with the older Galaxy S6-S7, and they get quite bogged down during NORMAL use.

I know this is pretty messed up for DJI to act as though theyre releasing state-of-the-art tech, but I wouldnt worry too much. I dont believe its a major issue as its quite predictable behavior for a heavily taxed android OS.

I do admit its still scary as F### though.

Sorry its not better news.

 

[Muddiver]

The first matter is your adjustment from 2 to 4GB. That is not relating to RAM, but how large of a storage allocation, within your SC, for cached video.
Thats not likely what caused of your issue...

Q: What SC firmware version you were running?
.530 or the latest .650? ( SC menu, near the bottom. Not in GO4 menu)

Ive been using the SC since about 30d after release. Ive done plenty of testing running CPU & RAM usage monitors. When the AC is off, and you run GO4, CPU runs at about 30%, add 10-20% for screen recording. As soon as the M2 is powered up and links to SC, that avg jumps to 95% with peaks at 100%.

That consistent usage had causes some screen lag and studder for me when using hyperlapse and other intelligent modes, but no disconnect relating to heavy CPU usage. (Had a few from signal loss but thats different!)
These results were before the .650 update (running .530 for the most part)

It was only after the .650 fw update, that I had similiar disconnects on 2 separate occasions, both within 1km.

IMO, DJI did some internal optimization changes, and as a side effect, introduced a few odd issues that were seeing, on occasion. What Ive noticed, post .650, is that the CPU usage is lower, on average, than the .530 and before... I wish I knew what they did but I think the changes were significant, internally (ie: coding), since you never get a performance boost like that without new disadvantages.

Your issue sounds slightly different than mine, in that you say you had no stick input and your AC hovered, instead of initiating RTH (as you had RTH upon disconnect selected, in the settings). Also, that your Go4 app restarted automatically, without your input.

This leads me to believe that while you had no stick input, I dont think you had a full disconnect, but rather your app blocked input for a moment while it self-reset and reacquired signal link.

While the strangeness of the event is enough to make any of us panic, It did fix your issue, all on its own.

My disconnect left the app screen black/white but I still had stick input, and my app never restarted. Upon flying in and landing, I powered down and swapped batteries, restarted AC, but still had no fpv on SC. I had to reset the GO4 app manually, and that did the trick. Flew another mission no problem.

Summary:
While we paid a hefty amount on these SC, its a sad fact that specs wise, the SC is on par with the older Galaxy S6-S7, and they get quite bogged down during NORMAL use.

I know this is pretty messed up for DJI to act as though theyre releasing state-of-the-art tech, but I wouldnt worry too much. I dont believe its a major issue as its quite predictable behavior for a heavily taxed android OS.

I do admit its still scary as F### though.

Sorry its not better news.

I'm running .650 update. Thanks @jzilla80 for trying to explain what happened. When I looked at the flight data on AirData, the data stops at the point the AC disconneted. There is no flight data from the point I regained control until it landed. Just more questions...

 

[jzilla80]

I'm running .650 update. Thanks @jzilla80 for trying to explain what happened. When I looked at the flight data on AirData, the data stops at the point the AC disconneted. There is no flight data from the point I regained control until it landed. Just more questions...

Yeah, thats happened to others before.

Whenever the Go4 app stops midflight, the log stored on the SC and in the Go4 app flight log area is never finalized and thus deleted.

If your desperate to find more details, which might still not be there, you can research how to download .DAT files direct from the M2. Ive not done this so no help there.

What I still cant figure out about your situation is even as your SC was disconnected, your AC was in hover, instead of RTH.

This would make perfect sense and be what your M2 was supposed to do, IF the Go4 app was simply restarting itself. This is because the SC, once pwrd on, is always connected with M2, even when Go4 is not running, as long as the M2 is in RF range. (Thats why you can fly w/o Go4).

Q: Are you sure you tried to move the M2 using sticks, during the time of this situation?

The answer to this question could change this issue to something less worrisome, BUT I also fully understand its hard to be sure during a situation such as yours because of the sort of panic that always causes.

Thats mainly why I always screen record, then delete it IF there was no issues, but chances are a full system reboot such as what your SC did, wouldve auto stopped that as well, whereas a Go4 app restart would not.

So I guess thats where were at, you had a Go4 app autorestart (not too major of a situation) OR your SC had to stop and restart several subsystems within your SC?

If your curious about monitoring background processes, you can go to developers options, (If youve not unlocked it yet, go into SC menu, go to bottom, tap on "about remote cont" then find "system version" Tap on it 7-8 times. Youll see notification on screen.) and find running processes (just good info for nerds, if your interested). Also, theres a good app called 'simple system monitor' which can be found on apkmirror.com. It will allow you to pull up small windows that show CPU use and RAM.

I never saw RAM get much use, but again, a way to test this out IF it happens again, but I dont believe youll be having these issue regularly.

One last small tidbit which might help clear the cache for each flight, thus lowering the burden on SC (This is a new method Im trying with good results so far). After each flight, after youve powered off the M2, go into SC recents tab and swipe up (kill) the Go4 app. Then swap M2 batteries, power up M2 and once "GO" button, on home screen, turns blue, tap that and restart Go4 and have fun.
(If your using screen record or above monitoring app, the restarting of Go4 sometimes kills them)

So yeah, kindve alot of BS to worry about for a $750 RC huh. Keep in mind, you dont need to do all the things I do. I just have an interest in how things work. I dont see you having issues regularly regardless, especially if you restart Go4 manually before each flight/battery!

Good luck

EDIT: crap man, sorry about the length on this again. I guess I get carried away.

 

[Muddiver]

Yeah, thats happened to others before.

Whenever the Go4 app stops midflight, the log stored on the SC and in the Go4 app flight log area is never finalized and thus deleted.

If your desperate to find more details, which might still not be there, you can research how to download .DAT files direct from the M2. Ive not done this so no help there.

What I still cant figure out about your situation is even as your SC was disconnected, your AC was in hover, instead of RTH.

This would make perfect sense and be what your M2 was supposed to do, IF the Go4 app was simply restarting itself. This is because the SC, once pwrd on, is always connected with M2, even when Go4 is not running, as long as the M2 is in RF range. (Thats why you can fly w/o Go4).

Q: Are you sure you tried to move the M2 using sticks, during the time of this situation?

The answer to this question could change this issue to something less worrisome, BUT I also fully understand its hard to be sure during a situation such as yours because of the sort of panic that always causes.

Thats mainly why I always screen record, then delete it IF there was no issues, but chances are a full system reboot such as what your SC did, wouldve auto stopped that as well, whereas a Go4 app restart would not.

So I guess thats where were at, you had a Go4 app autorestart (not too major of a situation) OR your SC had to stop and restart several subsystems within your SC?

If your curious about monitoring background processes, you can go to developers options, (If youve not unlocked it yet, go into SC menu, go to bottom, tap on "about remote cont" then find "system version" Tap on it 7-8 times. Youll see notification on screen.) and find running processes (just good info for nerds, if your interested). Also, theres a good app called 'simple system monitor' which can be found on apkmirror.com. It will allow you to pull up small windows that show CPU use and RAM.

I never saw RAM get much use, but again, a way to test this out IF it happens again, but I dont believe youll be having these issue regularly.

One last small tidbit which might help clear the cache for each flight, thus lowering the burden on SC (This is a new method Im trying with good results so far). After each flight, after youve powered off the M2, go into SC recents tab and swipe up (kill) the Go4 app. Then swap M2 batteries, power up M2 and once "GO" button, on home screen, turns blue, tap that and restart Go4 and have fun.
(If your using screen record or above monitoring app, the restarting of Go4 sometimes kills them)

So yeah, kindve alot of BS to worry about for a $750 RC huh. Keep in mind, you dont need to do all the things I do. I just have an interest in how things work. I dont see you having issues regularly regardless, especially if you restart Go4 manually before each flight/battery!

Good luck

EDIT: crap man, sorry about the length on this again. I guess I get carried away.

That is a lot @jzilla80 LOL. I was moving the sticks and got no movement which is why I looked down at the SC to see what was going on. The SC didn't restart, just the Go4 saying "disconneted" which is why I'm thinking of your original theory that the reason the M2 didn't RTH was because it didn't loose signal with the SC, just the Go4 when it crashed and that's why the M2 wasn't getting any input when I tried. Again just my theory based on what we've talked about. I like your idea of using screen record and I'm going to try that and open the developers options so I can see more of what the SC is doing. Where is the "recent tabs" in the SC? A diagnostic tool like 'simple system monitor' would be helpful too.