Need help understanding Phantom 4 Pro V2.0 & Crystalsky Ultra Aircraft Disconnect

[SpaceDesign]

Hello fellow pilots, I hope this finds you all very well.

Really appreciate if some of you more experience pilots, who can read an aircraft flight log, can help me understand what may have occurred during a flight today

I was flying Phantom 4 Pro V2.0 with Crystalsky Ultra, at an altitude of 230m, 120m away and received "Weak Signal adjust antenna..." pop up. Antenna where parallel to each other and in the 60 degree position pointing to aircraft. Crystalsky reported "Aircraft Disconnected" and locked up the display which went from colour to black and white, I dropped altitude to bring the aircraft closer, however it did not reconnect, I rebooted the Go 4 app, no joy reconnecting to aircraft, and then rebooted the Crystalsky and relaunched Go 4, but still no reconnect.

The aircraft didn't go into return to home mode, which was surprising, however with time to think, I assume this was because the controller was still connected to the aircraft. I was in VLOS and could land the aircraft ok.

Go 4 flight log only goes as far as the point of disconnect. DJI Assistant is not yet working very well getting the aircraft flight logs from the P4P V2.0 but I found some workarounds and managed to get the aircraft flight logs off P4PV2.0. That said, I am not very experienced yet at reading the data and telemetry.

I extracted the 2 last 2 flight logs from DJI Assistant, and have them uploaded to dropbox, here are the links:

Dropbox - FLY075.DAT
Dropbox - FLY076.DAT

If any of you could be so kind as to take a moment to review the logs, and see anything jumps out, I would be eternally grateful. I'm trying to see if the problem was the pilot, the aircraft, the Crystalsky, or Go 4 locking up.

 

[Fly Dawg]

On a quick look I don't see anything in FLY075 that strikes the attention. You were indeed connected via the RC for the entire flight however. See if you can pull the .txt data file from the Crystal Sky. Not sure it will reveal anything more, but it may have the signal levels in that file prior to downlink loss. Upload those to the link below and share a link back for a comparison. Instructions are on the link.

DJI Flight Log Viewer

 

[SpaceDesign]

Thank you very much Fly Dawg for taking the time to review, may I ask what you use to review the flight logs? I looked at them Assistant and all I could see charts, but I don't know if I was looking at it right, I could see no maps or content I could understand.

Text file from Crystalsky can bee seen in this link:

DJI Flight Log Viewer - PhantomHelp.com

See anything?

 

[wa5tef]

Your antennas should be parallel and flat side pointed to drone. Never have ends of antennas pointed towards drone!
Jim
WA5TEF

 

[Fly Dawg]

I looked at them Assistant and all I could see charts, but I don't know if I was looking at it right, I could see no maps or content I could understand.

Signal levels are not in this file either. So, not much good as far as that goes. However, this file "appears" to be a complete signal loss. The last report was at 10:47.5 in to the flight at 752ft in altitude and 211.8ft in distance. That says to me that the log stopped, which matches what you said in reference to "Never Reconnected" in your description. Assuming this matches the .dat file FLY075 you had RC connection the entire flight, just no video downlink. In most "disconnect" cases you always lose downlink first. And as for your question, I generally use the converted .csv files and use Excel. Then graph them in a seperate program. For the aircraft .dat files use Datcon.

 

[AeroMirage]

Like wa5tef said.
Here is an illustration

 

[Paul2660]

How were you able to get the flight logs from Assistant 2 for Phantom? I have tried many times and still can't get anything. I can connect, but the firmware levels and flight logs info I can't access. Pretty worthless to me. I would love to know what you did. I have opened a case with DJI, but that was a pretty much worthless process as I have started to realize that it appears most of the support folks have never even flown a drone, even less a Vr 2.0 as they keep referring to Assistant 2 for the data required and that software will not work.

Back to the Crystalsky.

I have had the same issues, too many times, both with the P4 Pro and now the P4 Vr 2.0. Even with updated Crystalsky firmware the app will freeze up just like you reported. This leaves me with either the black and white screen or just a frozen color screen. As you, I still have full control of the drone, but the last time this happened, I was at 2000' out and could not located it visually, so I had to just hit RTH and pray. I gone back to iPad Pro 10.5 for now with both Phantoms. Just too many issues with Crystalsky, which is unfortunate as it's a great monitor for daylight use.

No issues with mavic with same monitor.

I have not updated my version of Djigo4 to latest, on iPad, on the Crystalsky I believe I have the latest version as I updated it when I updated Crystalsky firmware.

Paul C

 

[Fly Dawg]

How were you able to get the flight logs from Assistant 2 for Phantom? I have tried many times and still can't get anything. I can connect, but the firmware levels and flight logs info I can't access.

Not being that familiar with the Crystal Sky, you might try a direct interface. Being that the CS is basically Android based, the directory structure should be similar, as opposed to using Assistant or even I tunes for that matter. Which is a real pain, but that's another issue. Try to locate the .txt files directly via PC. It "might" mount the CS as a removable drive. Just something you can try.

 

[SpaceDesign]

Signal levels are not in this file either. So, not much good as far as that goes. However, this file "appears" to be a complete signal loss. The last report was at 10:47.5 in to the flight at 752ft in altitude and 211.8ft in distance. That says to me that the log stopped, which matches what you said in reference to "Never Reconnected" in your description. Assuming this matches the .dat file FLY075 you had RC connection the entire flight, just no video downlink. In most "disconnect" cases you always lose downlink first. And as for your question, I generally use the converted .csv files and use Excel. Then graph them in a seperate program. For the aircraft .dat files use Datcon.

Thanks for the contribution Fly Dawg, Hmmmmm, Do you know of anywhere else there might be a record of signal levels? Is there a log in the controller?

 

[Paul2660]

Sorry I wasn't clear. You can still get the flight data from the Crystalsky, albeit a bit of a pain, you have to use the file explorer on CS, browse the logs and copy to a SD card. Then load from SD card to PC.

The problem I have with the Vr P4 is that the flight data on the actual drone can't be read. The only way I know to get it is via the Assistant software. For the Vr 2. it's Assistant 2 for Phantom (stupid name as it implies it works on all Phantoms which is doesn't). However after I make the initial connection (USB icon plugs into PC), and the software tells me I am connected, I can't browse the actual flight logs on the P4 Vr 2.0, when you try to go there the software just hangs, and gives the retry error.

I have told DJI about this, and their answer is that since the firmware is original the software can't load it. I have told them repeatedly that forget the firmware version, I should be able to see the flight data.

As I understand it, the actual .txt and .DAT from the Drone have the most detailed info.

Paul C

 

[Fly Dawg]

Do you know of anywhere else there might be a record of signal levels?

I cant guarantee this with the CS, but there is another device log. I know for a fact that all the other P4's record a .dat file on the IOS or Android device along with the .txt file. It is an in between file between the .txt and the aircraft .dat file. You could take a look and see. This is the first V2 I have looked at so I can't say for sure if it does or does not record the Device .dat file as all the other P4 models do.

 

[SpaceDesign]

Like wa5tef said.
Here is an illustration
View attachment 100378

Thanks guys, your dead right there with your observations. Very likely that this didn't help the situation, I was holding controller with lanyard at about 45 degrees, with antenna in the 60 degree notch so my antennas where pointing horizontal, that said I may have adjusted my stance and contributed to the disconnect.

That said, I'm still trying to figure out how come it didn't reconnect when it came back into range.

 

[SpaceDesign]

How were you able to get the flight logs from Assistant 2 for Phantom? I have tried many times and still can't get anything. I can connect, but the firmware levels and flight logs info I can't access. Pretty worthless to me. I would love to know what you did. I have opened a case with DJI, but that was a pretty much worthless process as I have started to realize that it appears most of the support folks have never even flown a drone, even less a Vr 2.0 as they keep referring to Assistant 2 for the data required and that software will not work.

Back to the Crystalsky.

I have had the same issues, too many times, both with the P4 Pro and now the P4 Vr 2.0. Even with updated Crystalsky firmware the app will freeze up just like you reported. This leaves me with either the black and white screen or just a frozen color screen. As you, I still have full control of the drone, but the last time this happened, I was at 2000' out and could not located it visually, so I had to just hit RTH and pray. I gone back to iPad Pro 10.5 for now with both Phantoms. Just too many issues with Crystalsky, which is unfortunate as it's a great monitor for daylight use.

No issues with mavic with same monitor.

I have not updated my version of Djigo4 to latest, on iPad, on the Crystalsky I believe I have the latest version as I updated it when I updated Crystalsky firmware.

Paul C

Hi Paul (incidentally I posted this reply to you on DJI Forums earlier, but glad to share how I did it with you here again for everyones benefit)

As you correctly say, there is an issue with Assistant 2 and the Phathom 4 Pro V2.0 accessing the flight logs. There is a constant scrolling wheel on my Mac in the Data Upload tab.

I found a workaround to get the flight logs from my Phantom 4 Pro V2.0 and DJI Assistant 2, latest version on to my computer which is an Apple Mac.

When I have the controller on, and the aircraft connected to mac via USB, I launch Assistant a click on a few of the left side tabs, a disk mounts on my desktop with the flight logs inside. Now, If I go into this, and select view as list via the Mac Finder menu, I can see the flight logs and date / time.

If I drag the log file to the mac, you will know it won't copy, however if I drag it into the Assistant App Data Upload window, where the scroll wheel was spinning earlier, a save dialog box appears and I can save my Log to the Mac HD, it takes a few moments for it to copy as there is no file transfer progress bar, but you can see the file size change in your finder view as it transfers via USB to the Mac. 300mb data file took a minute or two to transfer.

Hope this might help some of you.

 

[SpaceDesign]

I cant guarantee this with the CS, but there is another device log. I know for a fact that all the other P4's record a .dat file on the IOS or Android device along with the .txt file. It is an in between file between the .txt and the aircraft .dat file. You could take a look and see. This is the first V2 I have looked at so I can't say for sure if it does or does not record the Device .dat file as all the other P4 models do.

Fly Dawg, I reviewed the .TXT file and I have full signal strength for the full flight, until the disconnect as predicted.

 

[SpaceDesign]

Paul,

How to mount disk image instructions are here:

How to retrieve a V3 .DAT File from the AC

 

[Fly Dawg]

How to mount disk image instructions are here:

Yes, I know this. How do you think I read the original .dat files. The .dat files on the device are different. You should have a .txt and a .dat flight record on the device. The other .dat files ar on the aircraft itself.

 

[SpaceDesign]

Yes, I know this. How do you think I read the original .dat files. The .dat files on the device are different. You should have a .txt and a .dat flight record on the device. The other .dat files ar on the aircraft itself.

FlyDawg, those instructions where for Paul2660 not you!

 

[Fly Dawg]

FlyDawg, those instructions where for Paul2660 not you!

Well sometimes I will miss a quote or two.......Point Taken.......

 

[Paul2660]

Hi Paul (incidentally I posted this reply to you on DJI Forums earlier, but glad to share how I did it with you here again for everyones benefit)

As you correctly say, there is an issue with Assistant 2 and the Phathom 4 Pro V2.0 accessing the flight logs. There is a constant scrolling wheel on my Mac in the Data Upload tab.

I found a workaround to get the flight logs from my Phantom 4 Pro V2.0 and DJI Assistant 2, latest version on to my computer which is an Apple Mac.

When I have the controller on, and the aircraft connected to mac via USB, I launch Assistant a click on a few of the left side tabs, a disk mounts on my desktop with the flight logs inside. Now, If I go into this, and select view as list via the Mac Finder menu, I can see the flight logs and date / time.

If I drag the log file to the mac, you will know it won't copy, however if I drag it into the Assistant App Data Upload window, where the scroll wheel was spinning earlier, a save dialog box appears and I can save my Log to the Mac HD, it takes a few moments for it to copy as there is no file transfer progress bar, but you can see the file size change in your finder view as it transfers via USB to the Mac. 300mb data file took a minute or two to transfer.

Hope this might help some of you.

Thanks for this,

I will try it tomorrow.

Paul C

 

[BudWalker]

Hello fellow pilots, I hope this finds you all very well.

Really appreciate if some of you more experience pilots, who can read an aircraft flight log, can help me understand what may have occurred during a flight today

I was flying Phantom 4 Pro V2.0 with Crystalsky Ultra, at an altitude of 230m, 120m away and received "Weak Signal adjust antenna..." pop up. Antenna where parallel to each other and in the 60 degree position pointing to aircraft. Crystalsky reported "Aircraft Disconnected" and locked up display went from colour to black and white, I dropped altitude to bring the aircraft closer however it did not reconnect, I rebooted the Go 4 app, no joy connecting to aircraft, and rebooted the Crystalsky and relaunched Go 4 but still no connect.

The aircraft didn't go into return to home mode, which was surprising, however with time to think, I assume this was because the controller was still connected to the aircraft, as I was in VLOS and could land the aircraft ok.

Go4 flight log only goes as far as the point of disconnect. DJI Assistant is not yet working very well getting the aircraft flight logs from the P4P V2.0 but I found some workarounds and managed to get the aircraft flight logs off P4PV2.0. That said, I am not very experienced yet at reading the data and telemetry.

I extracted the 2 last 2 flight logs from DJI Assistant, and have them uploaded to dropbox, here are the links:

Dropbox - FLY075.DAT
Dropbox - FLY076.DAT

If any of you could be so kind as to take a moment to review the logs, and see anything jumps out, I would be eternally grateful. I'm trying to see if the problem was the pilot, the aircraft, or the Crystalsky locking up.

The first part of FLY075.DAT matches the .txt you submitted. Could you take a look and please provide the .txt immediately after DJIFlightRecord_2018-06-22_[11-18-37].txt

The uplink signal strength is about 71% for most of the flight except for a 5 sec interval at 665 secs. 8 secs later you applied negative throttle which caused the P4P to descend.

Normally, a signal strength of 100% would be expected for most of this flight. DatCon computes sig strength as percentage of dropped frames.. Maybe there is a subtlety involving the CS that causes this calculation to be off.

The P4P didn't lose connection with the Go App until you recycled the CS power at 741 secs. The sig strength was still 71%.

So the Go App stopped recording the .txt at 649 secs but the P4P continued to think the Go App was connected. I seem to recall another P4P/CS where this happened.