Using custom ROMs on Android devices

skiguy1701 · Mar 27, 2017

Hi Brian;
Thanks for all your updates. I have the exact same tablet. My drone is the P3S. I also tried almost the same rom upgrade path as you did (stock, CM, Slim). The only rom that never crashed the DJI GO or Litchi app was the stock Samsung 4.4.2 (KitKat). Based on your experiments on Nougat (7.1.1), I also grabbed the latest unofficial LineageOS 14 build. The GO app was mostly stable but it did crash one time in 4 flights. Using CM 13.1 both GO and Litchi would crash multiple times during the same flight.

Litchi on the other hand has yet to crash on my Tab Pro 8.4 running LineageOS 14.1. So for now I am going to stay with Nougat and Litchi.

Hope this helps
Jim

Brian Fist · Mar 27, 2017

See, I wish the stock ROM wouldn't have crashed.

Quick question, did you get to run it before or after the January update pushed by Samsung?

If I am correct, that update caused more harm than anything. I never, not once, had an app crash or hang or anything on this tablet in the past year and a half. Once the update in January happened I ended up having a number of "glitches" that caused hung apps or apps just exiting out without warning.

Now, I did NOT do a "factory reset" on that tablet after the January update, and maybe that was the problem. Then again I have had Galaxy SIII, a S5, Note Pro 12.2, Note 10.1 2014 and never once have I had issues with apps after a firmware update.

Then again, knowing the disdain Samsung had for the Galaxy Tab Pro 8.4, it wouldn't surprise me if they tried to kill it off.

For now I will continue to rock 5.1.1 until I run into any issues. The actual filename of the rom I am running: cm-12.1-20161124-UNOFFICIAL-mondrianwifi.zip

Honestly, on all my devices, I really don't care the version of Android, as long as it runs the apps I want. The only issue I had with 4.4.2 KitKat was the fact that you couldn't access the SD card over wifi without root access. So stupid, especially on a device that can utilize a 128gb or 200+gb MicroSD card.

But, I do really like the form factor, the screen, the speed and everything else about the Tab Pro 8.4. It is almost a crime to make it a dedicated flight tablet.

Then again, I also have a Fire HDX 7" that is used as a garage media-player. That thing has a killer display, great audio, even smaller form factor, but it is stuck with FireOS... I can sideload apps, but honestly, for a media-player it doesn't need to be much else.

TMM777 · Mar 28, 2017

smiller said:
Just to clarify for those not familiar, the Nexus 7 2012 and the Nexus 7 2013 are two very different models. The former is generally considered inadequate for DJI GO while the latter has a much faster processor and higher res screen, and while not leading edge these days it still performs quite well with DJI GO/Litchi.

And yes, while the N7 2013 performs well under 6.0.1 the N7 2012 is better left at 4.4.4.

New to DJI here. Little experience with issues surrounding Android OS. I want to know what the difference is between the N7 2012 and 2013. My N7 says it's 2012 but has the smooth back (no perforations) and logo is horizontal/landscape. My N7 has been rooted with Wugfresh to 7.0. 3 flights and one app crash. Should I change that to a different (more stable) Android OS. If so which one?

skiguy1701 · Mar 28, 2017

@Brian: I rooted my Tab Pro 8.4 and was running CM13 long before I got my P3S. When I discovered the issues with CM 13/SlimRom with GO and Litchi, I used ODIN to flash the factory 4.4.2 image dated March 2015. Since my device was rooted and the KNOX bit tripped, my tablet refused any new updates from Samsung, I was stuck in 2015. So bottom line I never took the January update.

So in your case I would stick with CM 12.1 if that is working for you. I myself never tried CM 12.1. Otherwise flash via ODIN the 2015 stock image and run that. The downside is TouchWiz and all the Samsung crapware.

hope this helps
Jim

Brian Fist · Mar 28, 2017

Thanks for confirming that about the earlier stock release. I figured it was Samsung messing with tablet owners that was causing all my issues.

In regards to ROMs and flashing, I bought my Tab Pro 8.4 second hand. The original owner had it flashed to CM12.1 and since I was using it for general use at the time I figured I would go back to stock firmware and I do believe I used Odin also and loaded the factory firmware back on and KNOX never indicated it was a non-factory firmware and I received the one and only update OTA without issue.

All of that is moot if CM12.1 works well. If not I will be forced to go back to the Samsung stock 4.4.2... In which case I think I will root it and attempt to remove as much of the bloat as I can. Honestly, that stuff isn't bad if it is functional, but on the Tab Pro 8.4 more than 7/8 of all the online service stuff is defunct and unavailable (remember the "unable to contact server" error you get twice a day on the stock ROM?) and the rest was just unfinished "fluff" more than anything. I am also concerned you can't strip the stock OS enough to get rid of anything that would conflict. Basically that would end up rendering the tablet useless for drone duty.

Brian Fist · Mar 29, 2017

Well, another update in the Custom ROM saga:

So, I got a chance to go out and do some flying today. I even took the training wheels off and did some aggressive flying in Sport mode. I also got "brave" and flew the bird a good mile plus away. Most of my flying today was done at around 400ft.

The good news is that I had successful flights and my bird came back home each and every time.

The even better news is that I did not have a single glitch in DJI GO 4!!!

I did a bunch of taking pics, recording video off and on, landings/taking off, even took it so far out of LOS I got signal degradation errors and even "aircraft disconnect" errors. But all the while I had perfect video while connected, upon reconnection the video picked back up and was solid and in general I couldn't be happier that the bird/controller and tablet all functioned the way you would expect them to function. I was flying on 5.8GHz with "Auto" channel selection as a data point. I would expect the range to get better on 2.4GHz, so I will check that out next time, but for limited distance flying 5.8GHz works great.

I must say, you had better be in a fairly large area that doesn't have anything that could screw up an automated landing, since I was taking off/landing from my driveway and if I was near the end of the driveway it would give me errors that you need to pick a better landing spot because of the gutter transition, and one time it almost came down on top of my conversion van that was parked further up the driveway.

Also I noticed it basically would constantly reset the "precision take-off/landing" option under the OA settings. Oh, also on one automated take-off it went well above the 3.9m height and had to settle back down to it.

Lastly, I did a full IMU calibration and gimbal calibration before taking off and I still had a tilted horizon. The IMU calibration was done in the house on a perfectly leveled table, so next time I will spend some time setting up a perfectly flat and level location outside and do it out there along with a full compass calibration and then a gimbal calibration.

But, in regards to the tablet, looks like CM12.1 aka Lollipop 5.1.1 is a winner. After all my flying and it still connected with WiFi via the router in the house, my tablet was showing 80% battery available, which is great. I should have no problem going through 4-6 batteries on a full tablet charge. Next I have to configure my tablet to tether to my phone via WiFi while I am out and about.

Next time I am flying I am also going to start getting used to flying in ATTI mode. Once you are high enough up the "protections" in P/S mode don't matter much anyways since it is clear flying.

Brian Fist · Mar 29, 2017

TMM777 said:
New to DJI here. Little experience with issues surrounding Android OS. I want to know what the difference is between the N7 2012 and 2013. My N7 says it's 2012 but has the smooth back (no perforations) and logo is horizontal/landscape. My N7 has been rooted with Wugfresh to 7.0. 3 flights and one app crash. Should I change that to a different (more stable) Android OS. If so which one?

Actually, I believe that is a 2013 N7. If so, try 5.1.1. You should be able to find the proper ROM from google themselves with no need to run a hacked OS. Only the 2012 N7 had issues with 5.1.1 due to the type of memory they used, your 2013 version should be fine.

The only reason the rest of us *HAVE* to run a custom ROM is because our tablet(s) are no longer supported by the manufacturer, or they are supported improperly (bloatware and hardware/software issues). Your 2013 N7 has factory "clean" ROMs available for it. Go with those. That is a "reference" device, thus it guaranteed the best compatibility and Android experience running a clean OS.

Most people that switch to newer ROMs do it, well because I have NO IDEA WHY! Honestly, some people just want the "latest and greatest". Others think they are missing out on something. Personally only a few apps are requiring newer OSes and even those are pretty much "OK" on 5.1.1 Lollipop.

TMM777 · Mar 30, 2017

Brian Fist said:
Actually, I believe that is a 2013 N7. If so, try 5.1.1. You should be able to find the proper ROM from google themselves with no need to run a hacked OS. Only the 2012 N7 had issues with 5.1.1 due to the type of memory they used, your 2013 version should be fine.

The only reason the rest of us *HAVE* to run a custom ROM is because our tablet(s) are no longer supported by the manufacturer, or they are supported improperly (bloatware and hardware/software issues). Your 2013 N7 has factory "clean" ROMs available for it. Go with those. That is a "reference" device, thus it guaranteed the best compatibility and Android experience running a clean OS.

Most people that switch to newer ROMs do it, well because I have NO IDEA WHY! Honestly, some people just want the "latest and greatest". Others think they are missing out on something. Personally only a few apps are requiring newer OSes and even those are pretty much "OK" on 5.1.1 Lollipop.

Thank you for the reply. Since I didn't do the rooting on this ( i bought it that way) I have no idea how to get it back to the way it was. Can you point the way?

TMM777 · Mar 30, 2017

Brian Fist said:
Actually, I believe that is a 2013 N7. If so, try 5.1.1. You should be able to find the proper ROM from google themselves with no need to run a hacked OS. Only the 2012 N7 had issues with 5.1.1 due to the type of memory they used, your 2013 version should be fine.

The only reason the rest of us *HAVE* to run a custom ROM is because our tablet(s) are no longer supported by the manufacturer, or they are supported improperly (bloatware and hardware/software issues). Your 2013 N7 has factory "clean" ROMs available for it. Go with those. That is a "reference" device, thus it guaranteed the best compatibility and Android experience running a clean OS.

Most people that switch to newer ROMs do it, well because I have NO IDEA WHY! Honestly, some people just want the "latest and greatest". Others think they are missing out on something. Personally only a few apps are requiring newer OSes and even those are pretty much "OK" on 5.1.1 Lollipop.

Brian, I see a lot of folks referring to a CM number in reference to Android OS builds. I don't get that. What am I missing? Finally I am a bit confused. Isn't the factory build going to have a bunch of bloatware that will get in the way of the DJI go 4 app? The current rom on mine (WugFresh) is really clean of apps. My tablet is only 16gb with no expansion slot. I need the OS and all the apps to just get out of the way and not clog my tablet. My wish is to run DJI go 4 nearly exclusively on my tablet. I would include a Google browser and an email client. Anything else is not wanted. Thanks again for your help.

DanMan32 · Mar 30, 2017

Any idea where to get CM 12.1 for Galaxy Tab E 9.6? I tried to go to the official CM site, says quota exceeded.

Brian Fist · Mar 30, 2017

TMM777 said:
Brian, I see a lot of folks referring to a CM number in reference to Android OS builds. I don't get that. What am I missing? Finally I am a bit confused. Isn't the factory build going to have a bunch of bloatware that will get in the way of the DJI go 4 app? The current rom on mine (WugFresh) is really clean of apps. My tablet is only 16gb with no expansion slot. I need the OS and all the apps to just get out of the way and not clog my tablet. My wish is to run DJI go 4 nearly exclusively on my tablet. I would include a Google browser and an email client. Anything else is not wanted. Thanks again for your help.

Actually, the Nexus branded devices all got "vanilla" OS images from google. The only thing they have is Google apps installed. No other bloatware, so that is the BEST option for your tablet. Honestly, do not even look at anything else.

If I had a "Nexus" stock ROM available for my tablet, I would have flashed it and not looked back.

Oh, and to answer your first question, the CM (CyanogenMod) build numbers are:

10 = 4.2 Jelly Bean
11 = 4.4 KitKat
12 = 5.0 Lollipop
12.1 = 5.1.1 Lollipop
13.0 = 6.0 Marshmallow
13.1 = 6.0.1 Marshmallow
14.1 = 7.1.1 Nougat

And those are the only ones I know off the top of my head, I am sure there are plenty more...

Brian Fist · Mar 30, 2017

DanMan32 said:
Any idea where to get CM 12.1 for Galaxy Tab E 9.6? I tried to go to the official CM site, says quota exceeded.

CM is no longer.

The replacement is LineageOS.

For your tablet, check this out: [UNOFFICIAL][ROM] LineageOS for Galaxy Tab E [SM-T377P/SM-T560NU]

I hope it helps.

DanMan32 · Mar 31, 2017

I might try that. Video stability is unpredictable as it is now.

TMM777 · Apr 2, 2017

Brian Fist said:
Actually, the Nexus branded devices all got "vanilla" OS images from google. The only thing they have is Google apps installed. No other bloatware, so that is the BEST option for your tablet. Honestly, do not even look at anything else.

If I had a "Nexus" stock ROM available for my tablet, I would have flashed it and not looked back.

Oh, and to answer your first question, the CM (CyanogenMod) build numbers are:

10 = 4.2 Jelly Bean
11 = 4.4 KitKat
12 = 5.0 Lollipop
12.1 = 5.1.1 Lollipop
13.0 = 6.0 Marshmallow
13.1 = 6.0.1 Marshmallow
14.1 = 7.1.1 Nougat

And those are the only ones I know off the top of my head, I am sure there are plenty more...

Thank you for your considered reply. I really appreciate your time. I did not root this tablet. I know it was rooted with wugfresh. How do I get beck to a stock Nx7 android os? Which build should I use? Not root savvy.

skiguy1701 · Apr 2, 2017

TMM777 said:
Thank you for your considered reply. I really appreciate your time. I did not root this tablet. I know it was rooted with wugfresh. How do I get beck to a stock Nx7 android os? Which build should I use? Not root savvy.

Youtube is your friend here. I just used these search terms:
restore nexus 7 2013 to stock

good luck and have fun!
Jim

TMM777 · Apr 3, 2017

skiguy1701 said:
Youtube is your friend here. I just used these search terms:
restore nexus 7 2013 to stock

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good luck and have fun!
Jim

That is a very old video but it did encourage me to look around. I didn't root my tablet. I do know it was rooted via Wugfresh. Looking at their website I found that their software will allow me to go back to stock rom. I think there is a choice from 4.3 to 6.01. Which one is the best choice?

TMM777 · Apr 3, 2017

TMM777 said:
Thank you for your considered reply. I really appreciate your time. I did not root this tablet. I know it was rooted with wugfresh. How do I get beck to a stock Nx7 android os? Which build should I use? Not root savvy.

I discovered that WugFresh was the software that rooted my NX7 2013. Their site says that I can step back to the stock rom. The choices are 4.3 to 6.01. What is the best choice?

Brian Fist · Apr 3, 2017

TMM777 said:
I discovered that WugFresh was the software that rooted my NX7 2013. Their site says that I can step back to the stock rom. The choices are 4.3 to 6.01. What is the best choice?

For compatibility with DJI GO 4, choose 5.1.1.

TMM777 · Apr 6, 2017

Brian Fist said:
For compatibility with DJI GO 4, choose 5.1.1.

Brian, (I want to write Brain) My Nexus 7,2013 is successfully turned back to 5.1.1. It automatically upgraded my first attempt to 6.01 Marshmallow. I redid it and it is back to a proper build of 5.1.1 that was designed for this Model. The boot loader is still open. I did not do an OEM lock. Now I am at the point of the welcome screen of 5.1.1. How do I avoid the auto upgrade to 6.01? How do I shut down the system updates? You answers are always clear and concise, thank you.

Brian Fist · Apr 6, 2017

For preventing the update, first off don't choose, "Install", just choose "Later".

Next follow this thread to prevent updates:

Support - Nexus 7 how to disable android updates?

That should help you take care of it.

As far as the bootloader, doesn't matter either way. An open bootloader only gives you the ability to root in the future. It doesn't affect the way the tablet runs. If you had a Samsung or LG or any other Android device, it might lock you out of things, but on Nexus devices it really does not matter.