video repeats lines and fills bottom part of screen

[tjcooper]

I was using my Sensa cell phone this weekend. The screen often shows repeated lines of video on the bottom portion of the screen. It is like 20 lines are of repeated video, then a new line comes in, and that new line now forms 20 repeated lines, and so on. This happens most often when there are other DJI drones at the field, but it has also happened when I am the only drone on the field.

This "lock up" stays active for about 20-30 seconds and then the video becomes "live" again the problem is gone. This also happened on my Nexus 6 so I am sure it is not a slow down of my Sensa phone (which by the way is a FANTASTIC DEAL at $20 for a 5.5 inch phone from StraightTalk). If I were flying beside some trees this lock up would be a serious problem. It always locks up the bottom of the screen. Never the top.

This slow down of the video is very strong for typically 2-3 minutes and then everything goes back to normal for a while. Has anyone else seen this problem? Is there a FIX?
tjcooper

 

[Divebomber]

I have heard of a number of problems with video. I myself experience brief lock ups that last just long enough to give me a minor heart attack, so I'll be buying a controller soon. I use an iPhone 6s, so I don't think the issue is phone related. As you said, it doesn't seem to be caused by the phone. I've found that I have fewer frame drops and lock ups, if I turn off all but wifi. I turn off blue tooth and cellular as I fly, so that only wifi is broadcasting. Theoretically cellular and blue tooth should not conflict with the wifi, but there's a concept called "beat frequencies" in which radio waves which shouldn't conflict, actually affect each other. It's the same concept as beat frequencies in accoustics. I don't have an O-scope, so I can't test to see if this is what's causing the problem, but I'm suspicious about it. The other thing that could be causing it is the amount of processing power your phone has. If there's other stuff running on the phone along with the Tello app, it might be causing the problem. This is probably the more likely cause. Again, no empirical evidence, just a suspicion.

 

[Kilrah]

This slow down of the video is very strong for typically 2-3 minutes and then everything goes back to normal for a while.

This suggests phone overheating and throttling down.

Might want to try/borrow a "real" modern phone and see if it happens there. The nexus 6 is also a bit dated and has had previous reports of not running GO4 well.

 

[tjcooper]

I have an iPhone 8S and an iPhone 10 at work (I test cameras for Amazon) and I could take those home and try them some weekend, but my intuition is that I am getting OCUSYNC drop out for a certain part of a frame and the system keeps the last few lines it has of video and replicates them.
Maybe I will also try a Samsung S9....it has the fastest core processor out there at this time,.
tjcooper

 

[tjcooper]

update: someone suggested that my putting in a large SD card into the Sensa may cause it to slow down processing time. Not sure why an SD card in a phone that has no calling plan will slow it down, but I have learned over the past 5 years of testing cell phones at Amazon that just holding the phone wrong in your hand can cause processing problems. So who knows. Anyone else out there seen this repeat of video lines at the bottom of the screen happen? Other people sometimes refer to this as pixelation, but technically that is a different function.
tjcooper

 

[Mossiback]

You could try...
• Putting the phone in airplane mode
• Ensure no other apps are running
• Turn off cashing to the phone
• A different connection cable
• Connect via USB (unplug side cable from RC)
• Turn on the RC, MP, and phone (in that order, phone after RC and MP connect)
• A different Go 4 app version

I also had bad video and disconnects on my Tab A due to a background upload of Go 4. Downgraded to v 4.1.15 and now is very solid. I am sure there are newer versions that would work for you but have not tried them. When you do get it to work, turn off auto-updating so it will not change unless you want it to.

 

[jegibson]

I have heard of a number of problems with video. I myself experience brief lock ups that last just long enough to give me a minor heart attack, so I'll be buying a controller soon. I use an iPhone 6s, so I don't think the issue is phone related. As you said, it doesn't seem to be caused by the phone. I've found that I have fewer frame drops and lock ups, if I turn off all but wifi. I turn off blue tooth and cellular as I fly, so that only wifi is broadcasting. Theoretically cellular and blue tooth should not conflict with the wifi, but there's a concept called "beat frequencies" in which radio waves which shouldn't conflict, actually affect each other. It's the same concept as beat frequencies in accoustics. I don't have an O-scope, so I can't test to see if this is what's causing the problem, but I'm suspicious about it. The other thing that could be causing it is the amount of processing power your phone has. If there's other stuff running on the phone along with the Tello app, it might be causing the problem. This is probably the more likely cause. Again, no empirical evidence, just a suspicion.

This has become the norm from DJI updates. It's why it scares the crap out of me everytime I do an upgrade for the first several flights. I've had to downgrade several times due to crappy video feeds. How they can release updates with crap like this happening is beyond me.

 

[jegibson]

I have heard of a number of problems with video. I myself experience brief lock ups that last just long enough to give me a minor heart attack, so I'll be buying a controller soon. I use an iPhone 6s, so I don't think the issue is phone related. As you said, it doesn't seem to be caused by the phone. I've found that I have fewer frame drops and lock ups, if I turn off all but wifi. I turn off blue tooth and cellular as I fly, so that only wifi is broadcasting. Theoretically cellular and blue tooth should not conflict with the wifi, but there's a concept called "beat frequencies" in which radio waves which shouldn't conflict, actually affect each other. It's the same concept as beat frequencies in accoustics. I don't have an O-scope, so I can't test to see if this is what's causing the problem, but I'm suspicious about it. The other thing that could be causing it is the amount of processing power your phone has. If there's other stuff running on the phone along with the Tello app, it might be causing the problem. This is probably the more likely cause. Again, no empirical evidence, just a suspicion.

In what I've found the app itself breaks when they release updates. This is a repeating issue. You can use apkpure to get an older version to install after removal g the crap update.

 

[tjcooper]

Jegibson,
can you give a little more details of how and where to get "apkpure" so I can move my upgrade back to v 4.1.15? And how to shut off automatic updates on DJI Go 4.

I tried my NEXUS and got same problem.....and again there were 3 other DJI modules running at our field. Even worse was the pop-up dialog saying I was near an airport and I have to hit "accept" and "confirm" to make dialog go away. I have already signed up for permission to fly close to airport and given DJI the credit card number to show good faith. It worked for a few weeks, but now I cannot get 30 seconds of flight time at our park without the dialog reappearing. BTW, I have no other apps running...don't even have a SIM card in the unit. No cacheing allowed. tried new side cable. Will try the RC, MC,App order this weekend (sure I have accidentally done it, but need to apply direct knowledge when I try it.

Does anyone know how to overcome this DJI caused problem? Much thanks.
tjcooper