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Timur's Kernel - USB ROM - Most popular thread on Rootzwiki

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OP Timur

Timur

Android Master

Posted 02 January 2013 - 06:42 AM #61

When I take power away the devices stop being connected to the N7. I will make a quick video demonstrating to maintain the plausibility of my sanity.


When you switch power back on in the video, your N7 screen goes off just a few seconds later. When using the fixed installation kernel and the same power source for N7 + hub, the return of external power will normally reset the N7 screen-off timer and your screen should stay on, at least for 15 seconds longer (depending on your configuration). I really don't understand why you want to individually power your N7 and fiddle with "shared ground" issues and such. Depending on your hubs ability to use a dedicated power source, there are two options available:

Option 1: Use this when your USB hub does not provide an external power connector. Connect external power directly to arm 1 of your OTG Y-cable and connect your USB hub to the other arm. Power will flow to hub and N7 in *parallel*. You can disconnect your N7 and power will continue to flow to your hub and to all connected slave devices.

Option 2: Your USB hub provides it's own power connector. You can still use Option 1, but you can also feed power directly to the hub. Then use an OTG Y-cable to make your N7 become the USB host (arm 1) towards the hub *and* have it draw power (arm 2) from one of the hub's slave connectors.

In regard to the "ignition-off postpone" functionality: this should work with both options. But with option 2 your N7 would also benefit from the extended power time. If for whatever reason you need to use a different setup and can't get it to work, then please provide a circuit drawing.
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Sengir

Sengir

Member

  • 21 posts

Posted 02 January 2013 - 09:06 AM #62

Works flawlessly! Awesome!.. BTW I'm still using the pogo pins audio out for my car setup because of the lack of hotswap between USB audio and speakers.. I would love if it will be possible to switch without rebooting the system..
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bru

bru

Member

  • 18 posts

Posted 02 January 2013 - 09:29 AM #63

When you switch power back on in the video, your N7 screen goes off just a few seconds later.

When you switch power back on in the video, your N7 screen goes off just a few seconds later. When using the fixed installation kernel and the same power source for N7 + hub, the return of external power will normally reset the N7 screen-off timer and your screen should stay on, at least for 15 seconds longer (depending on your configuration). I really don't understand why you want to individually power your N7 and fiddle with "shared ground" issues and such. Depending on your hubs ability to use a dedicated power source, there are two options available:

Option 1: Use this when your USB hub does not provide an external power connector. Connect external power directly to arm 1 of your OTG Y-cable and connect your USB hub to the other arm. Power will flow to hub and N7 in *parallel*. You can disconnect your N7 and power will continue to flow to your hub and to all connected slave devices.

Option 2: Your USB hub provides it's own power connector. You can still use Option 1, but you can also feed power directly to the hub. Then use an OTG Y-cable to make your N7 become the USB host (arm 1) towards the hub *and* have it draw power (arm 2) from one of the hub's slave connectors.

In regard to the "ignition-off postpone" functionality: this should work with both options. But with option 2 your N7 would also benefit from the extended power time. If for whatever reason you need to use a different setup and can't get it to work, then please provide a circuit drawing.

When using the fixed installation kernel and the same power source for N7 + hub, the return of external power will normally reset the N7 screen-off timer and your screen should stay on, at least for 15 seconds longer (depending on your configuration). I really don't understand why you want to individually power your N7 and fiddle with "shared ground" issues and such. Depending on your hubs ability to use a dedicated power source, there are two options available:

Option 1: Use this when your USB hub does not provide an external power connector. Connect external power directly to arm 1 of your OTG Y-cable and connect your USB hub to the other arm. Power will flow to hub and N7 in *parallel*. You can disconnect your N7 and power will continue to flow to your hub and to all connected slave devices.

Option 2: Your USB hub provides it's own power connector. You can still use Option 1, but you can also feed power directly to the hub. Then use an OTG Y-cable to make your N7 become the USB host (arm 1) towards the hub *and* have it draw power (arm 2) from one of the hub's slave connectors.

In regard to the "ignition-off postpone" functionality: this should work with both options. But with option 2 your N7 would also benefit from the extended power time. If for whatever reason you need to use a different setup and can't get it to work, then please provide a circuit drawing.


Thank you for the reply. The screen went off because of a tasker profile I didn't let finish where it shuts off the screen.

I have considered option 2 before, where essentially the N7 would loop back into the hub for its power. I thought I might have power problems only being able to draw 500mA though. The other problem there is that I'm actually going to be using all 4 available hub slots. This method certainly works because the N7 is always receiving power at the same time as the USB devices. I picture this as more of a work around than a full understanding of what is happening. I'd like to get down to the real reason why the devices disconnect and see if I can figure something out.


Thanks,
bru
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dcplaya

dcplaya

Android Beginner

  • 332 posts

Posted 02 January 2013 - 01:18 PM #64

Can anyone recommend a USB hub that will supply the N7 with AC power as well a USB DAC and a keyboard? I will be mounting it in a car as well.
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OP Timur

Timur

Android Master

Posted 02 January 2013 - 02:28 PM #65

One slightly offtopic question: do you modify anything else in these kernels?


There are no modifications other than those well described USB power mgmt fixes. And standard USB_AUDIO and CIFS drivers being enabled.
Should I ever intend to add anything else (nothing is planed at this point), you can be sure it will be clearly documented.
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OP Timur

Timur

Android Master

Posted 03 January 2013 - 02:44 AM #66

I found out what is causing these crashes. A proper fix is coming.


I made new mobile-use and fixed-installation kernels for stock JB 4.2.x available for download via: http://timur.mobi/files

I think you will like this release. (And no, I do not favor stock JB over CM10.1. Rather the contrary. Plan is to get the stock JB kernels fully stable. Then move the necessary changes over to CM 10.1. And then use CM 10.1 as a base for new/extended functionality. Watch out.)

Edit: change log
- improved stablility, preventing crashes in some edge case in both variants
- better handling of deep sleep situations in both variants
- improved external power detection in the mobile-use variant

Edited by Timur, 03 January 2013 - 03:06 AM.

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diba320

diba320

Average Android

  • 9 posts

Posted 03 January 2013 - 03:42 AM #67

THX for the quick release, just a question from someone who is too lazy to go via fastboot and prefers the *.zip Version going via TWRP directly on the N7. Could you compile one, I am not able to do and I understand if you say NO. No clue why all is underlined ...

Edited by diba320, 03 January 2013 - 03:44 AM.

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OP Timur

Timur

Android Master

Posted 03 January 2013 - 07:35 AM #68

No clue why all is underlined ...


The urgency detector does that! ZIP archive installers are also available now: http://timur.mobi/files

Edit: The zip installers have shorter file names, so they can be distinguished form each other in the recovery file selector. They contain the same boot image with the same kernel.

The JB kernels are now also available via the original download page: http://mehrvarz.gith...l-download-page
CM 10.1 kernels are coming soon...

Edited by Timur, 03 January 2013 - 11:11 AM.

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diba320

diba320

Average Android

  • 9 posts

Posted 03 January 2013 - 08:05 AM #69

Just found my way to flash via fastboot. Have not had the necessary patience to wait. Some trouble, because I upgraded to W8 lately and the "android -sdk" folder seemed to be somewhere else. Will report back as soon as I have checked how it works now.

Edited by diba320, 03 January 2013 - 08:14 AM.

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diba320

diba320

Average Android

  • 9 posts

Posted 03 January 2013 - 08:11 AM #70

W O R K S as it should EXCELLENT! THX
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