Develop Bugs

[Q] [Touch Issues] Only affects a specific part of the screen

Hi guys, just want to draw on your experience regarding the touch / grounding problems with the N7.2.
On a perfectly flat surface such as a table or stand my tab has the touch problems but restricted and specific to only the top part of the screen, within an inch of the notification / status bar. Now, is this touch problem specific to a device, is it as mine and restricted to certain areas of the screen or is it random (different parts of the screen at different times). The rest of the screen never experiences any problems
Holding the device in my hands results in no problems at all with touch, even resting on my lap there are no touch issues. I'm happy to keep the device if this is common behaviour, but if not I'd rather exchange it for a different unit, which may still have problems but at least it will be consistent with everyone else lol
Thanks

Same, my n7 is affected by the same grounding issue. No issues at all when holding it.
Sent from my Nexus 7 using xda app-developers app

Perhaps you want to try this and give some feedback?
Take that multi-touch! Fix and lock in what works for YOU regardless of updates

sfhub said:
Perhaps you want to try this and give some feedback?
Take that multi-touch! Fix and lock in what works for YOU regardless of updates
Click to expand...
Click to collapse
Not really as my n7 is pretty much factory in case I had / have to return. Hence why I asked the question. But I'll definitely take a look thanks

FIXED!!!!!!
sfhub said:
Perhaps you want to try this and give some feedback?
Take that multi-touch! Fix and lock in what works for YOU regardless of updates
Click to expand...
Click to collapse
Hey again,
Just wanted to reiterate what i've posted on your thread
Just tried fix 10 on my Nexus 7, Build number JSS15Q, Wed Aug 14 11:00.
I had touch issues on the top right of the screen, just below the notification menu within an inch, of the whole side / top. Unlocked the bootloader using WugFresh and Fastbooted the number 10 fix as recommend. Now on the stand, flat surface it recognizes the lightest of touches.
This was going to be my last attempt before returning the device the Tescos were i purchased it from for a replacement. I just wanted to make sure it wasn't a hardware issue.
Some tips:
If you have trouble installing drivers for your Nexus 7 2013 on your pc, other than making sure USB debugging is enabled, go to settings, storage, click the ellipsis in the top right corner, choose usb computer connection and change it to Camera (PTP).
Your Nexus 7 will display the computers id when you plug in the usb, select the tick box and click ok.
Also, if you're not sure about fastboot, I put the boot image in the C drive, users and the folder with my name. e.g. C:\\Users\Your_Name
Now in Command Prompt, if you type 'Dir *.img' it should show you your file. Then follow the instructions in sfhubs link above.
If you have any other trouble let me know and i'll post more detailed instructions on how i implemented the fix provided by sfhub. Check out his thread, link in the above post
Thanks!!!!!

Outside temperature

Hi,
does anybody know where I can see the outside temperature?
I have seen pictures where it's shown at the climate controls. But I don't see anything when I change the settings?
The sensor is working, my screen at the speedometer is showing ice warnings etc.
My unit is a rk3188 kgl
Car opel astra j

Pretty sure it's part of a weather app and requires an internet connection.

NYCAR said:
Pretty sure it's part of a weather app and requires an internet connection.
Click to expand...
Click to collapse
Not really. He's talking about info from his Can-bus system. The problem is that a lot of the Chinese
Can-Bus boxes actually don't work the way they should. I've have the same problem on Hyundai/KIA
boxes. They don't work the way they should.
The box for Analog to SPDIF works ie. sound conversion, but not the Can-Bus info.
Question for Crog1. Have you changed it for your brand of car in factory settings?

Yeah thanks, I had to change the canbus settings from gm raise to opel simple. Now it works.

Crog1 said:
Yeah thanks, I had to change the canbus settings from gm raise to opel simple. Now it works.
Click to expand...
Click to collapse
Were you able to change the units? I want it to show temperature in Fahrenheit. I am able to set it but every time I reboot, it resets back to Celsius.

Has anyone seen this issue with Steering Wheel app/settings?

My Steering wheel app is blank - no buttons, so I can't remap anything.
https://goo.gl/photos/H6Q8Lb8Z3E5GK2ia9
If so, does anything know how to fix the issue?
Xtrons support is crap. I would not buy anything from them. Their only suggestion is for me to return or refund it, when I keep telling them it's software issue and to actually look at another unit.

You will press the button it will appear on the screen then you choose the action
Sent from my SM-N920C using Tapatalk

elhamy said:
You will press the button it will appear on the screen then you choose the action
Sent from my SM-N920C using Tapatalk
Click to expand...
Click to collapse
4 of the 6 buttons on my steering wheel do things, but there are no buttons there to begin with, like shown here: http://kepfeltoltes.hu/141121/20141119_152125a_www.kepfeltoltes.hu_.jpg
When I press any of the buttons nothing happens in the steering wheel app. No buttons appear. If the button already does something, it just does it, instead of interacting with the app. The buttons that don't do anything, continue to not do anything. So basically the app isn't communicating with canbus adapter, but canbus adapter is working, since some buttons do stuff.

In your first picture the android version is 5.1.1 in normal cases when you press on your SWC they should appear and you will be able to link to an action
So if that is not happening with you I confirm that you have a problem and most probably a software problem so I suggest resetting the device to factory default and trying again
In the 2nd picture android version is 4.. which is a bit different in setting it up
Sent from my SM-N920C using Tapatalk

elhamy said:
In your first picture the android version is 5.1.1 in normal cases when you press on your SWC they should appear and you will be able to link to an action
So if that is not happening with you I confirm that you have a problem and most probably a software problem so I suggest resetting the device to factory default and trying again
In the 2nd picture android version is 4.. which is a bit different in setting it up
Sent from my SM-N920C using Tapatalk
Click to expand...
Click to collapse
Thanks for the suggestions. I've already tried to factory reset, but ended with the same results. My next attempt to fix it will be flashing stock factory rom... but my sdcard ejected and shot out and got lost between seat and center console. So waiting for new micro sd card.

same issue, on mi pumpkin unit.
I agree with you, the support is really crap 8 emails and nothing ...just ¨send it back¨
Don't buy Xtrons Units !

Eanon seems to have good support. They helped even though I didn't buy it from them. In any case, I had to press the swc first, then select which action I wanted it to take on screen.
Sent from my SM-N900T using Tapatalk

Honest question: Did you confirm that your SWC wires are properly connected?

My fix for SWC
I had the exact same problem with my
Joying . SKU: JY-UL124 . From China Warehouse
. Quad Core Android 5.1.1 Lollipop OS Capacitive 7" High Definition for Universal Double Din . CPU: RK3188 1.6GHz Cortex A9 Quad Core, Resolution 1024*600
. RAM：DDR3 1G, 16 GB memory
I fixed it by connecting a earth or ground to one (either) of the SWC control wires from the car.
The car's original wiring only had a "ladder" resistance network between the two SWC wires and had no earth. This works ok for OEM but the MTCB type head needed one of the wires to have an earth connection. The moment I connected the earth the missing SWC icons populated the screen and the setup was easy from then.
Hope that helps,
Duke

You guys need to post this in the MTCD thread and not the MTCB. Some or all of you have the 5.1.1 units which have different core boards (MTCD). The moderator of Android Auto thread has been pressing the issue of posting to the correct thread. The units may look the same but the software and hardware are different than that of the MTCB units.

Hi guys i would ask your help. I have an Alfa Romeo Giulietta, Installed in the dash a nexus 7 2013 and I want use the steering wheel buttons. The car use the protocol is 15765-4 29bit and I have on Bluetooth obd reader. Can you please help me out? Thanks in advance.
Inviato dal mio FRD-L09 utilizzando Tapatalk

Steering Wheel control app.
I realise that this is a 4 year old thread but did you solve your problem?
Did you set the canbus protocol in Settings/Car/Canbus to your specific car?
I'm having the same problem that my steering wheel app is blank!
Cheers
Onslow in the UK

Magnetic Case Sensor broken (?) - Device keeps locking up

Hello there,
My Flo-Device keeps locking me out, resulting in a short black screen and throwing me back to the lockscreen. Based on the behaviour it seems that this is related to the sensor that is use for magnetic cases.
Unfortunately, I never used such a case, most threads I found are talking about cheap cases with a poor placing of the magnet itself - which does not help me out here.
Any hints on overriding that sensor by software or hardware? Any way of fixing the sensor or even a hint on the location on the Motherboard? I have read about an exposed module disabling it, but to configure the module it may be neccesary to be able to use the tablet in the first place. Currently it is still completely stock.
I appreciate your help or any reference to a solution that I may have overseen in my search. Thanks!

AeroplaneMode said:
Hello there,
My Flo-Device keeps locking me out, resulting in a short black screen and throwing me back to the lockscreen. Based on the behaviour it seems that this is related to the sensor that is use for magnetic cases.
Unfortunately, I never used such a case, most threads I found are talking about cheap cases with a poor placing of the magnet itself - which does not help me out here.
Any hints on overriding that sensor by software or hardware? Any way of fixing the sensor or even a hint on the location on the Motherboard? I have read about an exposed module disabling it, but to configure the module it may be neccesary to be able to use the tablet in the first place. Currently it is still completely stock.
I appreciate your help or any reference to a solution that I may have overseen in my search. Thanks!
Click to expand...
Click to collapse
Hall effect sensor's location is on the first attachment. I can assure you that there is no need to fix it directly because this and many other sensor problems are caused by the LCM connector. Disconnect the battery and just re-seat the LCM connector but be careful, watch this first https://www.youtube.com/watch?v=C9PwK9eGrCY

k23m said:
Disconnect the battery and just re-seat the LCM connector
Click to expand...
Click to collapse
Thanks for the fast reply and for pointing out the sensors' location on the PCB. Unfortunately, this did not solve the problem. Do you have any other ideas?

AeroplaneMode said:
Thanks for the fast reply and for pointing out the sensors' location on the PCB. Unfortunately, this did not solve the problem. Do you have any other ideas?
Click to expand...
Click to collapse
Please also re-seat the other end of LCM cable.
Check if a magnet placed over the sensor's position (top or bottom) has any impact.
Perhaps ROM builders know if something can be changed in /system/build.prop
Remove lock password - start ADB and do:
rm /data/system/locksettings.db
rm /data/system/*.key
Finally, we'll consider a hardware mod.
:good:

I already reseated both end of the ribbon cable to be sure - and again after the first unsuccessful test run. I never used a magnetic case on the device and there ar no other magnets near - my other Nexus 7 is fine though
What exactly does the locksettings.db do? I deleted It and rebooted, but no change in behaviour.
btw, as I am unable to properly use the touchscreen, I tried to enable usb debugging via an usb-otg cable and an attached mouse - which worked fine so far. It seems that there might be some interference or mechanical problem. Maybe the first thought with the hall sensor was wrong track I repaired a lot of devices over time, but (un)fortunately none of them showed that behaviour before, so I'm somewhat out of ideas in this case.

AeroplaneMode said:
What exactly does the locksettings.db do? I deleted It and rebooted, but no change in behaviour.
....
I repaired a lot of devices over time, but (un)fortunately none of them showed that behaviour before, so I'm somewhat out of ideas in this case.
Click to expand...
Click to collapse
It removes the lock password and makes it go into LOCKSCREEN-NONE mode, but you have to also remove all files with the ".key" extension from the folder.
Since you repair such devices, then measure voltage on the output pin of the sensor, and measure it again with a magnet over it.

Good idea. Without the magnet I get 2.98 V and with the magnet 0.001 V between GND and out. So I guess the sensor itself may not be the problem? As I recognized that it might be a mechanical problem, I got a friend to use the touchscreen and measured output at the sensor again, it seems to work as intended.
As the lockscreen does not have any further protection set up after a factory reset, I guess this could be the reason that I did not find any *.key files in that directory? So currently it is just 'swipe to unlock'.
Problem with the lockseetings file is: The device is all stock, locked and has no root - and to get a bit more weird, is not recognized when in recovery. My other Nexus 7 with twrp already on it is recognized instantly. I may have to fix that first, as in a weak moment I may have overseen the "access denied" while trying to delete that file and already typing the nex command. My bad - it was already late.
Honestly, I wonder what the problem really is and really appreaciate your help so far.

AeroplaneMode said:
Good idea. Without the magnet I get 2.98 V and with the magnet 0.001 V between GND and out.
.....
As the lockscreen does not have any further protection set up after a factory reset, I guess this could be the reason that I did not find any *.key files in that directory? So currently it is just 'swipe to unlock'.
.........
Problem with the lockseetings file is: The device is all stock, locked and has no root - and to get a bit more weird, is not recognized when in recovery.
Click to expand...
Click to collapse
The sensor is OK indeed.
As you did factory reset, there is no issue of user data loss anymore, so just unlock it and do factory flash https://developers.google.com/android/images
This should fix the recovery recognition problem too.

Yeah, so I unlocked it, reflashed it with the stock rom, installed twrp and su...and finally got to delete the mentioned files. But still - the issue continues to exist. Also, I see no difference after deleting the files. Does something else prevent that no locksreen-mode?
Do you have any more ideas? I could wildly start changing parts, but unfortunately the device isnt worth that much anymore :-/ As mentioned, using the device with the Mouse hooked up via otg, the screen behaves normal.

AeroplaneMode said:
the issue continues to exist. Also, I see no difference after deleting the files. Does something else prevent that no locksreen-mode?
....
Do you have any more ideas?
Click to expand...
Click to collapse
No worries, we'll fix it, but it seems that my opening statement "this and many other sensor problems are caused by the LCM connector" still holds true. On the schematic, R150 and R151 are presumably located next to the sensor on the daughterboard, so if LCM cable connection to main mobo is open, the CPU will constantly sense 0V level, right? And as you measured earlier, 0V means that magnetic flux is detected. Now, about the ribbon cable... you did re-seat it, but this thing is awful and tends to fail repeatedly because of contact oxidation and weak connector lock pressure. Two solutions:
spray with https://www.amazon.com/CRC-5103-Quick-Electronic-Cleaner/dp/B000BXOGNI/
apply a thick tape/spacer over the lock so N7's back cover will add extra pressure on it
Finally, here is a brute-force workaround fix, go: settings - system profiles - default - lock screen - disable :highfive:

I'll test the points you mentioned.
I have to get a can of cleaning spray in the workshop, as I only have other fluids here which leave a oily coating. Or Brake Cleaner Fluid Thanks so far, I'll keep you updated.
Disabling the Lockscreen still gives me blackouts but okay, i dont have to swipe anymore - that will do for the moment. I haven't had similar problems in a while, so I tend to forget some points as repairing phones from time to time is only some sort of occupational therapy for me besides my other work ^^

k23m said:
[*]spray with https://www.amazon.com/CRC-5103-Quick-Electronic-Cleaner/dp/B000BXOGNI/
[*]apply a thick tape/spacer over the lock so N7's back cover will add extra pressure on it
Click to expand...
Click to collapse
I was finally able to continue here. I cleaned the connection and applied some tape to thicken up the spacers. Still, I am not able to resolve the problem. I also tried to manually apple more pressure on the back, still not getting better unfortunately.

AeroplaneMode said:
I was finally able to continue here. I cleaned the connection and applied some tape to thicken up the spacers. Still, I am not able to resolve the problem. I also tried to manually apple more pressure on the back, still not getting better unfortunately.
Click to expand...
Click to collapse
I know you're not happy about it but this is the best N7 hardware issue to resolve we've had so far this year
I opened up my N7 to check the sensor's connection to main PCB - it goes to LCM pin #41 - note the attached pictures. Disconnect the battery and use an ohmmeter to measure the two points - I get around 8 oHm. If you measure open circuit, then look for broken or corroded track somewhere along the way. If you measure proper connection, then the problem is on the motherboard and there is nothing else we can do - case closed unfortunately.
/EDIT
Here is a software workaround:
install ElementalX kernel
during installation select the "Disable magnetic cover on/off" option
:victory:

k23m said:
I get around 8 oHm.
Click to expand...
Click to collapse
I get 3 Ohms, so I flashed the suggested Kernel. It seems to solve the problem, won't get any better I guess. Thanks for your support!
k23m said:
I know you're not happy about it but this is the best N7 hardware issue to resolve we've had so far this year
Click to expand...
Click to collapse
Now is that a good thing? :silly:

Which board on the nexus 7 contains the gyroscope?

So, I recently installed Lineage OS on my n7 and noticed auto rotate wasn't working. Then flashed it back to stock thinking the lineage rom was bugged, still no auto rotate, it used to work last time I used the tablet around 3-4 months ago, so im wondering did the gyroscope get fried or something?
Anyway which board contains the gyroscope, the motherboard or daughterboard, anyone know? Recently replaced the daughterboard so im thinking that may control the gyroscope? I want to replace whichever board contains the gyroscope as it doesn't even show it moving in check my android app, don't really want to waste money on the wrong board if possible, so if anyone knows for certain it'd be a huge help!

chrisg4493 said:
So, I recently installed Lineage OS on my n7 and noticed auto rotate wasn't working. Then flashed it back to stock thinking the lineage rom was bugged, still no auto rotate, it used to work last time I used the tablet around 3-4 months ago, so im wondering did the gyroscope get fried or something?
Anyway which board contains the gyroscope, the motherboard or daughterboard, anyone know? Recently replaced the daughterboard so im thinking that may control the gyroscope? I want to replace whichever board contains the gyroscope as it doesn't even show it moving in check my android app, don't really want to waste money on the wrong board if possible, so if anyone knows for certain it'd be a huge help!
Click to expand...
Click to collapse
The gyro is on the daughterboard but it never fails. Connection of the wide silver cable between the boards is the problem - see my earlier post https://forum.xda-developers.com/showpost.php?p=66952073&postcount=3

k23m said:
The gyro is on the daughterboard but it never fails. Connection of the wide silver cable between the boards is the problem - see my earlier post https://forum.xda-developers.com/showpost.php?p=66952073&postcount=3
Click to expand...
Click to collapse
But then wouldn't the gyroscope show as moving in apps that can test it? It shows up as stuck, and on the twitch app it acts as if i am shaking the tablet cause it just keeps going from dark mode to light mode because twitch app has a feature that allows you to shake to enable dark mode/light mode.
Anyway I have tried re-seating the ribbon cable about 20 times now and still nothing shows up on gyroscope, even tried 2 different cables

chrisg4493 said:
Anyway I have tried re-seating the ribbon cable about 20 times now and still nothing shows up on gyroscope, even tried 2 different cables
Click to expand...
Click to collapse
The gyro and compass sensors share the same I2C data line connecting the two N7 PCBs. Please check with a sensor test app if the compass works - if yes, then the gyro has failed indeed.
Some apps will show you the sensors names - N7 has:
gyro Invensense MPU-6500
compass AKM AK8963
:good:

k23m said:
The gyro and compass sensors share the same I2C data line connecting the two N7 PCBs. Please check with a sensor test app if the compass works - if yes, then the gyro has failed indeed.
Some apps will show you the sensors names - N7 has:
gyro Invensense MPU-6500
compass AKM AK8963
:good:
Click to expand...
Click to collapse
Hmm, the compass seems frozen as well I don't understand though the ribbon cable seems to be fine no matter how many times I disconnect / reconnect it nothing seems to change... Very odd

I have same issue, I use rotate app to manually rotate and also automatically rotate some apps. Eg auto rotate YouTube and media player to landscape.
https://play.google.com/store/apps/details?id=jp.snowlife01.android.rotationcontrolpro

With the silver ribbon cable connected at one end try and get it tightly moulded around the battery hold it there and connect the other end. I found this out recently after a battery swap it helps to push the connecters in a bit more those few microns matter. I was having screen rotation problems after a recent battery swap after doing this everything's perfect again.