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

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millab

millab

Member

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Posted 11 January 2013 - 08:42 PM #131

Got it. I guess a devices, that can be operated on a small mobile battery for ages, shouldn't stress a big car battery too much. In particular not when it is just idling around doing nothing. Sure you did some research on this. Mind telling us more?


I have found that leaving everything powered for a week or more will not drain a car battery.
My current install is permanently powered, with both the tablet and the HDD being supplied 5v power constantly from a 5 Volt, 5 Amp regulator.
I have a microcontroller to control turning the tablet on and off using keypresses when it detects the key is turned to ACC or IGN.

I am looking forward to removing the microcontroller from my install to make things simpler. Unfortunately the old tablet's os couldn't detect when the power was connected to it. It was android 2.3 but was very buggy.

Edited by millab, 11 January 2013 - 08:45 PM.

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Kuchar09

Kuchar09

Android Lover

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Posted 11 January 2013 - 08:48 PM #132

That sounds like ground build up,try unpugging you audio cable touching it to ground it and then plugging it back in.If that helps its a grounding issue.

It did it before I put it in my car so its nothing do do with my grounds in my car. It did it before when testing with the Asus wall plug, charging y cable and just my USB DAC FiiO e10... It might have been wired with a USB hub but I don't remember.
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vorcers

vorcers

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Posted 12 January 2013 - 03:10 AM #133

Hello Guys,

it is possible to get that kernel working with the pogo pins? I received my nexus 7 dock yesterday and I tried around a bit with the stock kernel.

The Nexus 7 always shows that it get loaded, if it is in the dock. If I connect my usb-otg cable - even when no usb device is connected - my watt-meter drops from ~4W to 0W. If I remove the cable, after a short time, the Nexus 7 consumes again 4 W.

I didn't test Timur's Kernel because I don't want to blow up my device. Maybe you can give me some advice.


Thanks,

vorcers
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OP Timur

Timur

Android Master

Posted 12 January 2013 - 06:01 AM #134

it is possible to get that kernel working with the pogo pins? I received my nexus 7 dock yesterday and I tried around a bit with the stock kernel.

The Nexus 7 always shows that it get loaded, if it is in the dock. If I connect my usb-otg cable - even when no usb device is connected - my watt-meter drops from ~4W to 0W. If I remove the cable, after a short time, the Nexus 7 consumes again 4 W.



I started playing with the pogo pins some time ago. They may not be the ideal connector for a moving vehicle, but the pins were described as being able to pull 700 mA, so more than what you get from standard USB. I thought, it would be worth taking a look. This is what I found: the current kernel seems to have serious issues with dock support. A charger will be detected and power will be accepted from that source. But then things go bad. A charger disconnect will not be detected. The device will continue to display the charger symbol, even after the charger has been disconnected. Another problem: when getting power via popo pins, the amount of power accepted seems to be very, very low. Lower than what is accepted from a regular USB charger. And I am not talking fast charging here. This person on reddit seems to have the same issues: http://www.reddit.co...dock_has_so_far

I think a new kernel will be released soon. If you find out anything more, please let me know.

Edit: I can see no specific reason to not use my kernel when you own a pogo pin charger. As of now, it does not fix any of the dock related issues. It also doesn't add any new issues, it seems. Your benefit would be the ability to use USB host + USB charging when you are not using the dock.

Edited by Timur, 12 January 2013 - 06:12 AM.

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OP Timur

Timur

Android Master

Posted 12 January 2013 - 06:46 AM #135

I have found that leaving everything powered for a week or more will not drain a car battery.


I intend to go that same path.


My current install is permanently powered, with both the tablet and the HDD being supplied 5v power constantly from a 5 Volt, 5 Amp regulator.
I have a microcontroller to control turning the tablet on and off using keypresses when it detects the key is turned to ACC or IGN.


I will take a look at the issue you have described before. Pls be patient. (Hello @Kuchar09, I now understand the issue better. I am aware you described it first.) I hope you agree that this issue is rather edgy. I need to ask some more details. Are you using one power supply, or two separate ones? The USB cable, going from the N7 to the USB hub, does it have two wires (data only) or four wires (data + power)? In the latter case, you should be able to pull the dedicated power source from the hub and it should still be powered, correct? Maybe not powered enough, but at least power a little. Right? Generally speaking, all you special case people, just draw your wiring on a napkin, take a picture of that napkin and load it up. It would be good to have something to look at. Thank you.
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dcplaya

dcplaya

Android Beginner

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Posted 12 January 2013 - 08:48 AM #136

I feel dumb asking this because I know its been answered but I cant seem to find it.

On the fixed installation, I thought if power was lost and then regained (turn car off and then back on) the DAC would auto mount again. I wouldnt have to reboot for the DAC to come back up. Is this not fixed? (Or even possible)

I know its been talked about but ive been following this thread since the beginning and my brain isnt keeping things straight.
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Kuchar09

Kuchar09

Android Lover

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Posted 12 January 2013 - 09:39 AM #137

I intend to go that same path.




I will take a look at the issue you have described before. Pls be patient. (Hello @Kuchar09, I now understand the issue better. I am aware you described it first.) I hope you agree that this issue is rather edgy. I need to ask some more details. Are you using one power supply, or two separate ones? The USB cable, going from the N7 to the USB hub, does it have two wires (data only) or four wires (data + power)? In the latter case, you should be able to pull the dedicated power source from the hub and it should still be powered, correct? Maybe not powered enough, but at least power a little. Right? Generally speaking, all you special case people, just draw your wiring on a napkin, take a picture of that napkin and load it up. It would be good to have something to look at. Thank you.

When I first had the issue I did not have a separate power input for my hub only the one going to the otg y charging cable. When I was testing things before putting it in car I came to the conclusion that the I had to get an external powered hub. Instead I just took a 1ft USB extension and cut the power wire and tapped a male USB plug for power into the ground since there had to be a common ground or something, and connected the power wire going towards the hub. The power wire going into the tablet was unused.
Thus works just as it did before just doesn't draw any power from the tablet.
So to answer your question I have 3 wires connecting to my otg charging cable. Data +, data -, ground. I can draw a little diagram later no problem!
Also no rush on this issue it isn't a huge deal and only happens once in awhile. Keep up the great work man!!!
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Kuchar09

Kuchar09

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Posted 12 January 2013 - 09:42 AM #138

I feel dumb asking this because I know its been answered but I cant seem to find it.

On the fixed installation, I thought if power was lost and then regained (turn car off and then back on) the DAC would auto mount again. I wouldnt have to reboot for the DAC to come back up. Is this not fixed? (Or even possible)

I know its been talked about but ive been following this thread since the beginning and my brain isnt keeping things straight.

As long as you boot up the tablet with the DAC connected you can just off your car come back turn it on and it will automatically reconnect. My volume also works with the DAC to those who were talking about it earlier. If never had an issue with either of these features.

Edited by Kuchar09, 12 January 2013 - 11:05 AM.

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dcplaya

dcplaya

Android Beginner

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Posted 12 January 2013 - 11:25 AM #139

As long as you boot up the tablet with the DAC connected you can just off your car come back turn it on and it will automatically reconnect. My volume also works with the DAC to those who were talking about it earlier. If never had an issue with either of these features.


When I simulate a car off signal (disconnect charging power to my tablet) and then reconnect it. No sound comes out anywhere, neither my DAC or my tablet. I am currently powering my tablet via the USB hub though, would that make a difference?

And my DAC volume can be controlled via my N7 as well

Edited by dcplaya, 12 January 2013 - 11:34 AM.

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OP Timur

Timur

Android Master

Posted 12 January 2013 - 11:38 AM #140

On the fixed installation, I thought if power was lost and then regained (turn car off and then back on) the DAC would auto mount again. I wouldnt have to reboot for the DAC to come back up. Is this not fixed? (Or even possible)



To recap what FI kernel does:
  • In host mode, power is allowed to come in, where normally the formula is: host mode => OTG => host sending battery power to slave device(s).
  • FI kernel makes sure your host will not wake from deep sleep for no reason. The given USB connection in combination with active USB host mode can otherwise irritate the chip that is managing deep sleep and it can sporadically wake the host from deep sleep.
  • When external power goes away, FI kernel makes sure, your N7 will not start sending power to slave devices from battery. This is one of the things that would actually prevent your N7 from going into deep sleep itself (until the battery runs dry, of course). And sending power to slaves would also prevent your N7 from being able to detect external power coming back.
  • On waking up from deep sleep, the standard kernel may 'forget' about connected USB slave devices and may reset some needed client state. FI kernel fixes that, too.
So yes, when running FI kernel, your N7 should go to deep sleep peacefully. And when external power is back, it should immediately wake up and reconnect all your slave devices. This works really well in a lot of scenarios and with all sort of devices (mouse, keyboard, Ethernet adapter, USB DAC's and more). And once you get it to work with your particular setup, it should work all the time. But there can be (deep sleep related) issues, for example, with external file systems. When you are experiencing an issue, it may be that it is caused by some layer above the kernel. OS and apps sometimes hate to work properly *with external devices* after a good deep sleep.

When I simulate a car off signal (disconnect charging power to my tablet) and then reconnect it. No sound comes out anywhere, neither my DAC or my tablet. I am currently powering my tablet via the USB hub though, would that make a difference?


This, normally, does not cause any issues. Are you sure you are seeing the "-fi" identifier in the kernel signature under "About"? Please try the same thing with a different USB device, say, a mouse. Does it work before and after your "car off simulation"?

Btw, are you developer? In one of your previous posts you were referring to someone elses code as "hack". Regular people usually don't do this, most likely because it is not trivial for them to distinguish between "code" and "hack".

Edited by Timur, 12 January 2013 - 12:03 PM.

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