Nexus 7 2013 Timur's Kernel USB OTG + Charging is here

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holmes5518

Member
Apr 17, 2011
23
3
Hello everyone.

On my 2013 Nexus running 4.4.2 and Timur's kernel I am having no luck with tethering the internet from my phone. I have read countless accounts of it being a flaw of Kit Kat..

What do you folks use as a solution? The in car tablet is useless for me without internet. I really don't want to go back to the old 2012 Nexus with the crap DAC it has just so I can use internet.

Ideas?
 
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smalltownbird

Senior Member
Jan 27, 2010
411
64
So, need a bit of advice..

I mounted my Nexus 7 (2013) yesterday in my car, and i got a FM-Radio and JoyCon (to control steering wheels functions) connected to my USB powered hub.
Everything works fine, but my tablet doesn't charge as good as I want.. I got the Timur's Kernel installed, activated "USB Fastcharge".

I also got the "PowerGen" adapter that most people recommend.

On the way home from work, It didn't even charge 1% (about 20mins drive time), And the screen was on auto light (very low light level at the time).

Any idea? Is there any other configuration i need to go through?

Also, I'm not sure if the "Deep Sleep" works like it should.. Again it's activated in the small app, but it lose about 5%~ power during the night.
I haven't installed so many apps yet because I want to do it slow to make sure everything works..

Any idea? :)

From what I've seen on youtube, people claim that the kernel only drains 1-2% during night and charge up like crazy while driving.. heh.
appreciate some answers :)

Other than that, it works perfectly - so far.

I was having the same issue. I changed to a different USB cable and it charges extremely fast now

Sent from my HTC One_M8 using XDA Premium HD app
 

alb3rt018

Member
Jul 23, 2010
44
1
Orlando
Hello everyone.

On my 2013 Nexus running 4.4.2 and Timur's kernel I am having no luck with tethering the internet from my phone. I have read countless accounts of it being a flaw of Kit Kat..

What do you folks use as a solution? The in car tablet is useless for me without internet. I really don't want to go back to the old 2012 Nexus with the crap DAC it has just so I can use internet.

Ideas?

no problem with nexus 4 tethering to nexus 2013. do you phone provider charge for for hotspot? you need to have the right plan to tether to work and apn

---------- Post added at 01:42 AM ---------- Previous post was at 01:41 AM ----------

I've looked high and low and figured this would be the best place to ask this.

I'm experiencing some sever buzzing/hum/whine in my audio system when the tablet is charging. I've tried re-grounding everything, grounding the RCA jacks, different power adapters and cables but have had no luck. I can't post links yet, but if you search for "Nexus 7 2013 electrical buzzing" one of the youtube results shows exactly what I'm hearing.

I just donated for the kernel and have everything working except for this audio issue. It'd be a major waste of $40 if I can't fix this.

Has anyone had the same issue and resolved it? Any suggestions on other things I can try?

you need to find another ground spot.

---------- Post added at 01:44 AM ---------- Previous post was at 01:42 AM ----------

So, need a bit of advice..

I mounted my Nexus 7 (2013) yesterday in my car, and i got a FM-Radio and JoyCon (to control steering wheels functions) connected to my USB powered hub.
Everything works fine, but my tablet doesn't charge as good as I want.. I got the Timur's Kernel installed, activated "USB Fastcharge".

I also got the "PowerGen" adapter that most people recommend.

On the way home from work, It didn't even charge 1% (about 20mins drive time), And the screen was on auto light (very low light level at the time).

Any idea? Is there any other configuration i need to go through?

Also, I'm not sure if the "Deep Sleep" works like it should.. Again it's activated in the small app, but it lose about 5%~ power during the night.
I haven't installed so many apps yet because I want to do it slow to make sure everything works..

Any idea? :)

From what I've seen on youtube, people claim that the kernel only drains 1-2% during night and charge up like crazy while driving.. heh.
appreciate some answers :)

Other than that, it works perfectly - so far.

no problem on my nexus it got auto brightness on, my is always 100%. My tablet turn off when i turn off the car.
 

Merkoen

Member
Sep 27, 2013
22
4
suzukiblog.net
I was having the same issue. I changed to a different USB cable and it charges extremely fast now

Sent from my HTC One_M8 using XDA Premium HD app
Hmm. Thanks, will try that..
Perhaps the original Nexus charge cable will be good enough (if i find it).

Do you have the PowerGen adapter? Which one of the ports do you have the tablet connected to? "A" or "NA"

Thanks.
 

t1mur

Senior Member
Jan 20, 2013
129
58
timur.mobi
Battery drain in suspend mode when using Torque and/or DashCommand

This is the one remaining cause of battery drain in suspend mode, resulting in ~1% discharge per hour (10% in 12 hours). There is actually nothing wrong with the two apps. The issue is also not with my code. What we have here seems to be an Android bug. Unfortunately, neither 4.4.3 nor 4.4.4 is fixing the problem.

What seems to happen, is that the particular Bluetooth profile in use by the two apps (Bt serial profile?), will NOT close down when airplane mode is activated. And because the Bt radio will stay ON, the CPU will not suspend.

v2 kernel has the ability to execute a user provided shell script (/data/local/usersuspend.sh) before FI-mode is trying to push the device into suspend mode. When I configure these two lines...

killall com.palmerperformance.DashCommand
killall org.prowl.torque

...the two apps will be terminated, their Bluetooth connection will be closed down, airplane mode will succeed, the tablet will suspend just fine and the battery discharge in suspend mode will be no more than 2%/24 hours (or up to 1% overnight).

A nicer fix may become available in the future. However, going about it like this shows, that the issue is being triggered by these apps. And battery drain is effectively prevented. Other Bt apps (probably using other Bt profiles) do not seem to be affected.

Edit: "killall" shell command requires BusyBox.

Edit: I made the script available here: https://timur.mobi/files/dcmd-torque/usersuspend.sh
Download to your PC and run the following commands to install:

adb root
adb push usersuspend.sh /data/local/
adb shell chmod 755 /data/local/usersuspend.sh
 
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t1mur

Senior Member
Jan 20, 2013
129
58
timur.mobi
Also, I'm not sure if the "Deep Sleep" works like it should.. Again it's activated in the small app, but it lose about 5%~ power during the night.
I haven't installed so many apps yet because I want to do it slow to make sure everything works..

Any idea? :)

From what I've seen on youtube, people claim that the kernel only drains 1-2% during night and charge up like crazy while driving.. heh.
appreciate some answers :)

Other than that, it works perfectly - so far.

Battery drain in suspend mode when using Gapps

Other than with the Bt issue (above), your tablet is going to suspend mode. But 3rd party apps (or maybe I should say: apps that are not part of the base OS) are waking it up on a regular basis and for short periods of time, using the rtc alarm wakeup mechanism.

There are two solutions:
1. Uninstall (or disable) a number of Gapps and services -or-
2. Disable their respective rtc alarms http://forum.xda-developers.com/showthread.php?p=52851202#post52851202

Option 2 is available now as part of the v2 beta kernel installer for 4.4.4.
 
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stamatis

Retired Forum Moderator
Feb 5, 2012
2,836
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stamatis∈A, A=∅
Thread closed.

Xda is not the place to sell your work, if you don't want to share the fun for free with everyone then you are in the wrong place.


11. Don’t post with the intention of selling something.

Don’t use XDA to advertise your product or service. Proprietors of for-pay products or services, may use XDA to get feedback, provide beta access, or a free version of their product for XDA users and to offer support, but not to post with the intention of selling. This includes promoting sites similar / substantially similar to XDA-Developers.com.
Do not post press releases, announcements, links to trial software or commercial services, unless you’re posting an exclusive release for XDA-Developers.com.
Encouraging members to participate in forum activities on other phone related sites is prohibited.
Off-site downloads are permitted if the site is non-commercial and does not require registration.
Off-site downloads from sites requiring registration are NOT encouraged but may be permitted if both of the following conditions are met:
A) The site belongs to a member of XDA-Developers with at least 1500 posts and 2 years membership, who actively maintains an XDA-Developers support thread(s) / posts, related to the download.
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    More good news!

    By fixing a shortcoming in the default kernel, I was able to further reduce battery discharge in suspend mode.

    With this modification in place, discharge in suspend mode will not be "around 4% to 7% in 10 hours", like mentioned above, but more like 1% - 2% in 24 hours. This is with the OTG adapter plugged and all USB devices connected.

    It means, that you only need to charge your tablet for 6 minutes a day (or 45 minutes per week), to keep it at 100% charge level. And that your battery can stay operational through 50 days / 7 weeks of deep sleep. (Not yet tested in practice.)

    The screenshot below was taken after waking my device after nearly 22 hours of deep sleep:

    Screenshot_2014-04-03-14-19-30x.jpg


    This modification is implemented in FI-kernel 04-02 (or newer). Note: you need to have services 03-28b (or newer) installed as well. Both installers are immediately available for download.

    Thank you Kevin, for pointing me in the right direction.

    Mod edit: Link removed.
    4
    I am looking for a small number of users, ready to test Timur's Kernel v2.0 alpha on 4.4.3 (flo + deb).
    To begin with, you should have a rooted stock 4.4.3 on your tablet already.
    If things go well, I will do a v2.0 beta soft launch starting next week.
    By soft launch I mean a slowly widening user base for the v2.0 / 4.4.3 kernel.
    When the v2.0 kernel is confirmed to be as stable as the v1.0 kernel, the beta period will end - and the v1.0 release will be eol'd.
    If you are interested in participating, please drop me a line.
    4
    Thread closed.

    Xda is not the place to sell your work, if you don't want to share the fun for free with everyone then you are in the wrong place.


    11. Don’t post with the intention of selling something.

    Don’t use XDA to advertise your product or service. Proprietors of for-pay products or services, may use XDA to get feedback, provide beta access, or a free version of their product for XDA users and to offer support, but not to post with the intention of selling. This includes promoting sites similar / substantially similar to XDA-Developers.com.
    Do not post press releases, announcements, links to trial software or commercial services, unless you’re posting an exclusive release for XDA-Developers.com.
    Encouraging members to participate in forum activities on other phone related sites is prohibited.
    Off-site downloads are permitted if the site is non-commercial and does not require registration.
    Off-site downloads from sites requiring registration are NOT encouraged but may be permitted if both of the following conditions are met:
    A) The site belongs to a member of XDA-Developers with at least 1500 posts and 2 years membership, who actively maintains an XDA-Developers support thread(s) / posts, related to the download.
    B) The site is a relatively small, personal website without commercial advertising / links (i.e. not a competitor forum-based site with purposes and aims similar to those of XDA-Developers.com.)
    4
    Sounds cool, cant wait to see the stable release.

    Release v1.0 (May 06th and newer) has been made available to all my sponsors. After three month in beta, I am very confident with this release. Thank you very much for your support. If you cannot find the new installer, please contact me. I am still missing flo/deb info for a few users.

    Release notes: https://timur.mobi/timurs-kernel-n7-2013/updates

    Sorry, there will be no free-to-download version this time. My free-to-download solution for Nexus 7 2012 can be found here: http://rootzwiki.com/forum/513-nexus-7-development

    To get access to Timur's Kernel for Nexus 7 2013, you need to become a sponsor. Please check this page on May 12th: https://timur.mobi/timurs-kernel-n7-2013

    I will also make my kernel sources available to sponsors soon. Most likely starting the week after (May 19-25). If you like to get access to my kernel sources, please drop me a line.

    Timur
    4
    Quick update on the state of the project.

    I have spent the last couple of weeks fixing two specific issues related to suspend mode:

    Issue 1: On removal of external power, the screen was turning off, but the tablet did NOT transition into deep sleep. In this situation, the device would appear to be OFF, but the CPU was continuing to work and the tablet was discharging at a rate of about 4% per hour. In all cases this happened due to 3rd party "wake locks", preventing the device from entering suspend mode properly. All wake lock related issues should be fixed now.

    Issue 2: Device has transitioned to deep sleep, but would wake up randomly, due to 3rd party "alarm events". The modified "Firm Sleep" functionality will now take care of all of these issues.

    I added the following new info to PowerEventMgr, in order to make it possible for a user to verify proper suspend mode operations:

    PEM-screen-off-suspend-duration-2.jpg


    After waking a device from sleep (here: after ~10 hours), both duration values "Screen off" and "Last suspend" should be close to identical. It is OK for the two values to be roughly 60 seconds apart, like in the image above. This means that the tablet went into suspend mode ~60 seconds *after* the screen was switched off. And that the tablet did not wake up once during suspend mode. In full suspend mode, the battery will discharge 0.4% to 0.7% per hour (4% to 7% in 10 hours). Recharging back to 100% should be possible in about 20 - 25 minutes.

    None of the core "charging while in host mode" code has been touched in the last couple of weeks.