Command Timeout

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#1
Scary occurrence this evening. Flying my 3rd flight and suddenly I see “command timeout” warning and the screen goes blank. I was about 200 ft up and 1500 ft distance and had no control. Tried atti mode, restarting iPad, turning off controller and back on...no go. Luckily, hit s2 switch twice and return home initiated. Tried to cancel as I like to hand catch but still couldn’t gain control. Landed w/o incident...got lucky. Any ideas on what may have happened? This was a first for me in over 200 flights. Thanks.
 
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#2
Flying my 3rd flight and suddenly I see “command timeout” warning and the screen goes blank. I was about 200 ft up and 1500 ft distance and had no control. Tried atti mode, restarting iPad, turning off controller and back on...no go. Luckily, hit s2 switch twice and return home initiated.
This appears to be a brief loss of uplink signal. It was coincidental, that you reconnected for RTH, although RTH should have already initiated. The flight logs will tell you. Upload that flights log to the link below. If you do not understand what the logs tell you, place a link back here to the uploaded logs and we can let you know. Instructions are on the link.....

DJI Flight Log Viewer
 
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#3
Any other way I can upload? I no longer have access to a desktop computer. I only use an iPad Air and iPad Pro.
 
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#5
The only way I know to get at the files, is via iTunes, and for that you will need a PC or Mac running iTunes. I don't know of a browser for the iPad, may be one for a jail broken one.

If you have an Apple store near by, you could swing by there and quickly get the files off.

Once you have access to itunes, the instructions on this site will get you quickly through the process as Apple doesn't make it very clear cut.

Paul Caldwell
 
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#6
I dug out an old laptop and downloaded my flight records. Turns out, the record stops just before the command timeout occurred. So, unfortunately, I don’t have a record to upload. That being the case, any idea why this may have occurred? Seems very strange as I still had good signal strength right up until the sudden disconnect. Also, RTH has imitated every time I have lost signal...except this time. Any thoughts are greatly appreciated.
 
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#8
An interesting twist. I have the entire flight on video. I looked at the sd card last night and the recording continued after the command timeout warning and loss of signal. The video shows that I was stationary for approximately 3 minutes. The video kept recording even though I had complete signal loss. It shows that I rotated the drone several times and then after almost 3 minutes, it ascended to RTH altitude and started back. So, complete signal loss but still recording and no flight record after signal loss. Still trying to figure this one out.
 
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#9
An interesting twist. I have the entire flight on video. I looked at the sd card last night and the recording continued after the command timeout warning and loss of signal. The video shows that I was stationary for approximately 3 minutes. The video kept recording even though I had complete signal loss. It shows that I rotated the drone several times and then after almost 3 minutes, it ascended to RTH altitude and started back. So, complete signal loss but still recording and no flight record after signal loss. Still trying to figure this one out.
I don’t think it was a signal loss; at least not in my case. I believe either the RC wasn’t sending commands or the AC was not processing the commands it received. In either case it appears to be some sort of pathological case due probably to some obscure bug. It so far has not happened to me since.
 
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#11
An interesting twist. I have the entire flight on video. I looked at the sd card last night and the recording continued after the command timeout warning and loss of signal. The video shows that I was stationary for approximately 3 minutes. The video kept recording even though I had complete signal loss. It shows that I rotated the drone several times and then after almost 3 minutes, it ascended to RTH altitude and started back. So, complete signal loss but still recording and no flight record after signal loss. Still trying to figure this one out.
Without being able to view the logs this is all speculation. Just going from this description and nothing else for what it's worth, and this is only a WAG without any data to verify. This "appears" to be only a loss of "downlink", which you would still have control of the aircraft but no video feed or telemetry data. Therefore all of your stick commands were still functional. Again, guessing, after the 3 minute hover, your failsafe "Critical Battery" initiated the RTH. You would have not received any notification of this due to the "downlink" loss. Since you stated that you were able to view the logs, check your battery levels and you can verify that. Again this is pure speculation on my part, but it would completely explain the scenario you noted from the retrieved video.
 
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#12
Thank-you for your response. After the RTH and auto land, I wanted to send the drone right back up with the same battery to see if anything would happen. I turned off the battery, ipad, and controller and started the linking procedure from scratch. All connections were made and the drone lifted off. I then checked the battery level and it read 38%. I have critical battery set at 30% (first warning) so I don’t think RTH was initiated by low battery. That’s the part that puzzles me the most....what was happening in that 3 minutes and why did RTH suddenly engage? Again, thanks for your response. All of it made perfect sense except the RTH.
 
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#13
All of it made perfect sense except the RTH.
There is one more thing you can try, if you want. You could attempt to use the laptop to pull the .dat file from the aircraft itself. That will have the most data to work with. If you wish to try that, the link below will have instructions. Once you do this, you will need to upload that file to a sharable location such as Dropbox..etc....and place a shared link back here. Note: There will be numerous .dat files on the aircraft so it may be hit and miss to get the corrrect one. Some of those are quite large as well. If you want to give it a shot see the link.

How to retrieve a .DAT
 
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#14
Well, I see this is a few days old, but as this is, it is still hear-say and no data.

I would agree the OP still had control of the phantom.

If he had 38% battery this was a new power up, with or with out the props running?

Also, he stated he had turn the controller off and on, how long was it off?

Maybe the S2 switch did make it start RTH, if that is the case then he had control of the Phantom.

Another thought Smart RTH engaged and never got low enough on return to trigger the 30% level?

Rod
 
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#15
Last week, while flying a waypoint mission on Litchi, I lost connection which didn’t concern me because it happens all the time on longer waypoint missions. It was an 8 minute mission. After about 10-11 minutes, the AC still hadn’t returned. Went looking for it. It was on the ground, on the track of the mission. It had crashed. It had hit hard enough to break one landing gear leg and dislodge the battery about an inch out of the battery box. I restarted the AC and it said to calibrate the compass, which failed. Upon further inspection, it had broken the compass clip off the board. I haven’t found anyone locally who can do the intricate soldering yet so I ordered, received, and installed a new board (and landing gear). Linked everything up and did a test flight. DJI GO worked well (3500 feet with video). AC would not respond to LITCHI. Deleted and reinstalled LITCHI app last night. Took it out this morning and flew 6000 feet with Litchi. Brought it back, landed, changed batteries and got no video feed. Closed Litchi, opened DJI GO and got a ‘Command timeout’. From looking thru threads, I’m thinking the original crash was maybe due to a ‘compass error’ which put the AC in Atti mode but since I didn’t have connection and couldn’t see the AC, I didn’t realize. Still not comfortable with the process for downloading flight data so probably can’t give y’all the info you need to help me, just vocalizing my experiences this week.
 
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#16
Last week, while flying a waypoint mission on Litchi, I lost connection which didn’t concern me because it happens all the time on longer waypoint missions. It was an 8 minute mission. After about 10-11 minutes, the AC still hadn’t returned. Went looking for it. It was on the ground, on the track of the mission. It had crashed. It had hit hard enough to break one landing gear leg and dislodge the battery about an inch out of the battery box. I restarted the AC and it said to calibrate the compass, which failed. Upon further inspection, it had broken the compass clip off the board. I haven’t found anyone locally who can do the intricate soldering yet so I ordered, received, and installed a new board (and landing gear). Linked everything up and did a test flight. DJI GO worked well (3500 feet with video). AC would not respond to LITCHI. Deleted and reinstalled LITCHI app last night. Took it out this morning and flew 6000 feet with Litchi. Brought it back, landed, changed batteries and got no video feed. Closed Litchi, opened DJI GO and got a ‘Command timeout’. From looking thru threads, I’m thinking the original crash was maybe due to a ‘compass error’ which put the AC in Atti mode but since I didn’t have connection and couldn’t see the AC, I didn’t realize. Still not comfortable with the process for downloading flight data so probably can’t give y’all the info you need to help me, just vocalizing my experiences this week.
So, I formatted the sd card and reinstalled the fw(1-9-20). Took the AC out and flew DJI GO and Litchi. Everything seems to be back to normal.
 
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#18
"Still not comfortable with the process for downloading flight data"
Doing the procedure or sharing the data?

Rod
I watched a video about it this morning and was able to look at the flight data (DJI Go) on the app. There’s a button that says ‘share’. I’m assuming that’s how I could share it. I’ve done most of my flying with Litchi and haven’t figured out how to load the data onto my phone or computer. Biggest reason I would want to is so those of you with the knowledge could give me an idea why something went wrong.
 
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#19
I dug out an old laptop and downloaded my flight records. Turns out, the record stops just before the command timeout occurred. So, unfortunately, I don’t have a record to upload. That being the case, any idea why this may have occurred? Seems very strange as I still had good signal strength right up until the sudden disconnect. Also, RTH has imitated every time I have lost signal...except this time. Any thoughts are greatly appreciated.
You need to get the flight data from the drone itself. Since you still have the drone that would be the best way. The reason the iPad did not have all the flight data is because it lost connection. It couldn't keep recording. The drone will have the complete flight data. Just search in the forum how to get flight data off of drone, there are lots of existing threads on that topic so I won't explain it again, no use cluttering up the forum.

I did have an incident like this once. I was in my backyard outside of town, and I decided to orbit around the bell tower of the museum on main street. I took off my drone from my backyard and flew it into town. I had vlos but it was a tiny dot at this point, because the museum is almost a mile from my house. When I was done, the video was blocky and had a lot of dropoffs, so I decided to take it home. I initiated return to home on the app, and it started home for a few feet, but it suddenly stopped and the app crashed. I restarted the app, and it wouldn't do anything. I flipped the s2 switch up and down, and it came back home fine. This incident has only happened to me once, and that was a long time ago when I was new to DJI drones. Since then I NEVER use the app to initiate return to home, I ALWAYS use the s2 switch, and rth has always worked flawlessly since!
 
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#20
Yes, the mobile is only going to have the data while it had signal from the Phantom.

The data you want will be on the Phantom.

You need to connect a computer to the usb port on the Phantom front.

Have everything powered up, then in the app, pick download flight data. I think you can only use DJI-Go to do this.

The files are .dat, and there are to large to post here, you will need to share on a Dropbox, One drive, etc.

The will get analyzzzzzzzed.

How to retrieve a .DAT

Your turn. ;)

Rod
 

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