Phone disconnecting from Remote Controller

[Andyh77777]

I am very interested to learn whether anyone else has experienced disconnections between their remote control unit and their phone. I am not talking about situations where the interconnecting cable or the usb port on the controller is faulty. Neither am I talking about problems related to the order in which devices are started. Typically the problem appears with a message in the left hand side of the top message bar of the phone and it says either “Aircraft disconnected” or simply “Disconnected”. The controller remains in full control of the aircraft and all the usual telemetery continues to be displayed on the controller. The problem ususally arises mid-flight. Rebooting the phone never restores connection. Rebooting the controller does always restore connection between phone and controller.

The disconnection problem is far more prevalent on later versions of the firmware and Go4 release. I don’t think I have ever had a connection problem on firmware 01.04.100 combined with Go4 Ver 4.1.15 for example.

I am trying to isolate the problem to one of the following:

• FW version on the controller.
  
• FW version on the aircraft.
  
• Go4 software release version.
  
• Some combination of the three issues above.
  
• Intermittent defect in the controller.

The phones I am using are the Samsung Galaxy S5. They were originally on the DJI compatible hardware list for the Mavic Pro but at some later time it was removed from the list as far as I know. The technical age of the S5 could certainly play into the experience of problems with later software. However I remain sceptical because of the fact that only restarting the controller restores connection. If others have encountered the same experience then that would add weight to the theory that it is an old phone / firmware mismatch. On the other hand if the rebooting of the controller scenario has typically led to a failing controller then that would be very useful to know.

 

[Phantomrain.org]

I am very interested to learn whether anyone else has experienced disconnections between their remote control unit and their phone. I am not talking about situations where the interconnecting cable or the usb port on the controller is faulty. Neither am I talking about problems related to the order in which devices are started. Typically the problem appears with a message in the left hand side of the top message bar of the phone and it says either “Aircraft disconnected” or simply “Disconnected”. The controller remains in full control of the aircraft and all the usual telemetery continues to be displayed on the controller. The problem ususally arises mid-flight. Rebooting the phone never restores connection. Rebooting the controller does always restore connection between phone and controller.

The disconnection problem is far more prevalent on later versions of the firmware and Go4 release. I don’t think I have ever had a connection problem on firmware 01.04.100 combined with Go4 Ver 4.1.15 for example.

I am trying to isolate the problem to one of the following:

• FW version on the controller.
  
• FW version on the aircraft.
  
• Go4 software release version.
  
• Some combination of the three issues above.
  
• Intermittent defect in the controller.

The phones I am using are the Samsung Galaxy S5. They were originally on the DJI compatible hardware list for the Mavic Pro but at some later time it was removed from the list as far as I know. The technical age of the S5 could certainly play into the experience of problems with later software. However I remain sceptical because of the fact that only restarting the controller restores connection. If others have encountered the same experience then that would add weight to the theory that it is an old phone / firmware mismatch. On the other hand if the rebooting of the controller scenario has typically led to a failing controller then that would be very useful to know.

Before integrating all that , I would based on many other post consider getting a new cable first and foremost.
Than if that does not work, start isolating those aspects.

Phantomrain.org
Gear to fly your Mavic in the Rain.
Coal

 

[Andyh77777]

Before integrating all that , I would based on many other post consider getting a new cable first and foremost.
Than if that does not work, start isolating those aspects.

Sorry, I meant to indicate that I am not talking about situations where the interconnecting cable or the usb port on the controller is faulty. Many cables, including new ones, and both USB ports have been tried.

 

[Olav van Gerven]

Ever considerd it is neither the controller nor the cable but the phone that causes the problem?
I had disconnects using one specific tablet (cheap, no name), not when I used my phone. So I changed to another tablet and the problems are gone.

 

[Andyh77777]

Ever considerd it is neither the controller nor the cable but the phone that causes the problem?
I had disconnects using one specific tablet (cheap, no name), not when I used my phone. So I changed to another tablet and the problems are gone.

Yes Olav that is a good point to raise. I do believe that the increasing bloat that has been pushed out by Google and Samsung over the years had reached the point where it was compounding these problems. I did react to this by installing a custom version of Android on the phone with only services installed that are needed to support Go4 and Google Maps.

I am progressing now with the assumption that the phone is adequate. That certainly seems to be the case for the older firmware and Go4 version. It could be that the newer software is just too taxing for the S5, bit if that were the case I wouldn’t expect rebooting of the controller to restore normal operation, which is what happens.

I suppose I am trying to sound out the community to see if anyone has had a failing controller that gave rise to the symptoms I’m experiencing and where the situation was resolved by eventual replacement of the controller.

 

[Dave Maine]

The aircraft disconnected message is not from a phone to rc problem. It is a problem between the rc and ac.

 

[Papa72]

I was having the same problem with my Mavic Pro, but an S8. I didn't have the problem, but then I did. I deleted the DJI Go 4 software, then reinstalled it an, so far, have had no more problems. It was interesting that my preferences were kept with the new install.

 

[Andyh77777]

The aircraft disconnected message is not from a phone to rc problem. It is a problem between the rc and ac.

Yes that is what you would expect but in fact in the cases I am observing there is never a disconnect between the RC and AC in spite of the message “Aircraft disconnected”. The RC is still controlling the AC in every detail. When I reboot the phone that message usually reverts to “Disconnected”.

 

[Zonian]

I use a 3 year old S7 Edge and I have never had an issue since I dumped GO4 & switched to Litchi...very stable & solid.

 

[punkkone]

Also had problems with DJI 4GO, with multiple android phones, including a S7. Worked better with the full size USB-port, but still got the disconnections. Switched to Litchi and zero issues after that (also Litchi is superior in every single way, well worth the money)

 

[Andyh77777]

I believe I have overcome the phone disconnect problem with many faultless flights under my belt. After unsatisfactory results trying to tinker with random settings I went all out in winding back all software to earlier or de-bloated releases as follows:

• AC: Firmware V01.03.0700
  
• RC: Firmware V01.03.0700
  
• S5 Phone: Custom Android 7.1 from Resurrection Remix and Pico Gapps
  
• App: Go4 4.1.15

This has been rock solid for maybe 20 fights now.

I used to use Litchi before everything went pearshape with Go4. It is my hope to return to using Litchi for most projects but still have a safe fall-back to Go4 when needed.

It’s a shame that DJI didn’t elaborate on why it quietly removed the Galaxy S5 from it’s published list of compatible phones for the Mavic Pro. That could have saved me several months of troubleshooting and the pain of one significant crash due to lost control.

 

[punkkone]

I believe I have overcome the phone disconnect problem with many faultless flights under my belt. After unsatisfactory results trying to tinker with random settings I went all out in winding back all software to earlier or de-bloated releases as follows:

• AC: Firmware V01.03.0700
  
• RC: Firmware V01.03.0700
  
• S5 Phone: Custom Android 7.1 from Resurrection Remix and Pico Gapps
  
• App: Go4 4.1.15

This has been rock solid for maybe 20 fights now.

I used to use Litchi before everything went pearshape with Go4. It is my hope to return to using Litchi for most projects but still have a safe fall-back to Go4 when needed.

It’s a shame that DJI didn’t elaborate on why it quietly removed the Galaxy S5 from it’s published list of compatible phones for the Mavic Pro. That could have saved me several months of troubleshooting and the pain of one significant crash due to lost control.

The S5 was likely removed because of the Android OS version. The S5 (witout custom firmware) runs Marshmallow and backporting code to support that is simply not viable and requires the use of deprecated libs and packages and the use of a very old SDK.
It's strange however that DJI seems to handle the support from a per device basis and not by actual OS version.. Because hardware is pretty much irrelevant as long as the OS is up to date and correctly ported. Performance should be a non issue as the S5 is hardly slow.