[Q] Power on when plugged in (boot when docked)?

Nov 19, 2010
11
26
0
Appologies if this has been asked/answered here before. I tried searching, but didn't find any solution. Maybe someone else has stronger Google skills than I.

Here is what I am trying to do. I'd like to find a way to have the Galaxy Tab power on automatically when it is plugged in to power and begins charging. My company has several Galaxy Tabs (rooted) that are being used for a specialized purpose. They should be plugged in 24/7. However, it is possible that they will lose power, and the battery will eventually run down. When power is restored, I'd like to be sure that they come back on, without any user interaction.

I don't THINK this is the case, but it is worth asking: Is this a standard Android setting I can change anywhere?

I assume I will have to modify some code. Right now, I notice that when the Tab is turned off, and you plug it in, the charging indicator shows up and displays the battery levels. To me this indicates that code is running SOMEWHERE as soon as the Tab gets plugged in. I'd like to hijack that, and just have it power on.

Does anyone know where I should start looking for the code that runs when the device is plugged in? I found a charging.jpg in /mnt/.lfs that seems to be the image that displays, but so far no sign of what code is running. If there is any sort of init script, that would be amazing if someone could point that out.

Even if you don't know how to accomplish this, if you have any helpful pointers or "take a look at these files" to point me in the right direction, I'd really appreciate it.

As always guys, thanks for all the help!
 
Nov 19, 2010
11
26
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SOLVED: Power on when plugged in (boot when docked)?

Hey guys, I know that no one else may ever have any use for this, or even care, but I wanted to post an update. I was finally able to get this figured out through some guess work, trial and error, and looking at the work someone else did on a fairly similar project.

I owe plenty of credit to the fine work done by Chainfire on his project described in this link. His work, while not the same project, demonstrated that something similar to what I wanted to do WAS possible.

Anyway, to make the tablet boot up when first plugged in- The battery charging indicator that runs when you first plug in the Galaxy Tab is run from the file /system/bin/playlpm. To make it boot automatically, delete the old playlpm (or better yet, rename it to playlpm.bak, just in case) and replace it with the following script.

/system/bin/playlpm
Code:
#!/system/bin/sh
/system/bin/reboot
Be sure to set the ownership and permissions the same as the old playlpm. It didn't work for me at first because I had forgotten to give execute permission.

Thats all that it takes. Most of the time, the Tab should have enough power to go straight to booting. If the battery is really dead, it may flash the charging battery icon a few times, failing to boot until it gets enough charge. It will eventually come on.

I don't know of any additional side-effects for doing it this way, but there may be some, I don't know what else the stock playlpm is supposed to manage. This worked for my purposes though. Hope it could help someone else.
 

RickyLan

Member
Jul 7, 2006
27
0
0
Hi DavidThompson256,

Just want to say thank you for your research, I've been looking for the same thing a few months and just discovered your post.

I thought it is something to do to the kernel but looks like this simple mod can do the trick.

Thanks again!
 

prscott1

Senior Member
Nov 5, 2007
807
23
0
Houston
Ironically, I have an opposite problem. My phone automatically reboots when plugged in. My searching led me to your post. I installed the nomoarpower app but I could get it to keep my pad turned off. LOL
 

dhoai

Member
Sep 3, 2011
6
0
0
Did you have to root the tab before making this change?

Thinking about picking up the Galaxy Tab Plus but need it to do the same thing and boot when the power is plugged in.
 

knownchild

Senior Member
Dec 7, 2007
117
5
0
An update?

I have cm9 how do i find the file for my gsii?

there is no such file as the one you speak for my device, how did you find what file yours was?
 

Decert0

New member
Jan 6, 2013
1
0
0
As many others I dont have this file on my galaxy tab II

But i do have the kernel doing someing when pluged in when the device is not powerd on. First it tryed to show the splash img and then starts the charing animation. Does anyone know where this script is launched on a galaxy tab 2 7"?
 

rasssta

Member
Aug 11, 2010
6
0
0
Thank you! Been looking like a mad person for a solution like this for a couple of days and only found NoMoarPowah, which didn't fit my needs. :D
 

luuma

New member
Mar 26, 2013
1
0
0
on the s6500

thanks, this was really helpful. I've got this working on the Samsung Galaxy s6500 (mini 2), and I had to make a small addition to the script:

Code:
#!/system/bin/sh
su
/system/bin/reboot
Hey guys, I know that no one else may ever have any use for this, or even care, but I wanted to post an update. I was finally able to get this figured out through some guess work, trial and error, and looking at the work someone else did on a fairly similar project.

I owe plenty of credit to the fine work done by Chainfire on his project described in this link. His work, while not the same project, demonstrated that something similar to what I wanted to do WAS possible.

Anyway, to make the tablet boot up when first plugged in- The battery charging indicator that runs when you first plug in the Galaxy Tab is run from the file /system/bin/playlpm. To make it boot automatically, delete the old playlpm (or better yet, rename it to playlpm.bak, just in case) and replace it with the following script.

/system/bin/playlpm
Code:
#!/system/bin/sh
/system/bin/reboot
Be sure to set the ownership and permissions the same as the old playlpm. It didn't work for me at first because I had forgotten to give execute permission.

Thats all that it takes. Most of the time, the Tab should have enough power to go straight to booting. If the battery is really dead, it may flash the charging battery icon a few times, failing to boot until it gets enough charge. It will eventually come on.

I don't know of any additional side-effects for doing it this way, but there may be some, I don't know what else the stock playlpm is supposed to manage. This worked for my purposes though. Hope it could help someone else.
 

chtc2005

New member
Dec 4, 2007
2
0
0
Thank you. I have a galaxy tab p1000 in my car, with your help my tab will automatic turn on when engine start , it completed amazing :). Thanks again.

 
Last edited:

thompsos

Senior Member
Jul 18, 2007
149
95
0
Dallas/Ft Worth, TX
I made one minor tweak to the code, as follows:

Code:
#!/system/bin/sh
sleep 20
/system/bin/reboot
This makes the program wait 20 seconds between recognizing that the device is plugged in before issuing the reboot command. This helps ensure my device has enough juice to actually start, hopefully on the first try but if not, then on the second.

You can adjust the sleep length as desired - see here: http://www.cyberciti.biz/faq/linux-unix-sleep-bash-scripting/
 

XTDragonHawk

Member
Nov 9, 2009
10
2
0
I tried to install this app on my Galaxy Tab P1000. (Official Android 2.3.6 - rooted)
I always got the error message "202 - not enought space on /system ..."

So I installed MIUI V5 and MIUI V4 on my Tab.
I was able to install the app on both ROMs.
But both of them are not working properly.

If I turn off my device, it shows me the "new" battery info.
One second later, the display is getting darker.
One more second later, the display is turned off.
I am also not able to click on "reboot now".

(the timer option is working fine. I can set it to 2330 and the Tab will start at this time)

I want to use my Tab in my car instead of the built-in radio.
So I need that app getting working! :D

Please tell me which ROM u're using and which kernel :)

I'd be happy if someone else could help me with my problem :)
 

chtc2005

New member
Dec 4, 2007
2
0
0
XTDragonHawk said:
I tried to install this app on my Galaxy Tab P1000. (Official Android 2.3.6 - rooted)
I always got the error message "202 - not enought space on /system ..."

So I installed MIUI V5 and MIUI V4 on my Tab.
I was able to install the app on both ROMs.
But both of them are not working properly.

If I turn off my device, it shows me the "new" battery info.
One second later, the display is getting darker.
One more second later, the display is turned off.
I am also not able to click on "reboot now".

(the timer option is working fine. I can set it to 2330 and the Tab will start at this time)

I want to use my Tab in my car instead of the built-in radio.
So I need that app getting working! :D

Please tell me which ROM u're using and which kernel :)

I'd be happy if someone else could help me with my problem :)
Check pm, hope that can help you some.
 

majzok

New member
Oct 26, 2009
3
1
0
I have galaxy tab 2 p3100, replaced /system/bin/playlpm with given code, but after i plug charger nothing happens: just charging icons like always.
Anyone have idea how to fix this?
 

annlee

Member
Sep 1, 2013
21
1
0
Granada
play.google.com
I have galaxy tab 2 p3100, replaced /system/bin/playlpm with given code, but after i plug charger nothing happens: just charging icons like always.
Anyone have idea how to fix this?
Same problem here, did all the process including the correct permissions etc.. and appear battery stucked and then dark blue screen.

I am using samsung galaxy trand, as happens to your galaxy tab 2, seems our OS version 4 does something before playlpm or does not work, or am I wrong?

please help
 

BlancScha

New member
Oct 31, 2013
3
0
0
Petaling Jaya
auto power off when unplugged, and wont switch on

Its seems like my tab is crazy!

After installing cm 10.1 cdesai.zip my tab is currently having problems with data provider, debug mode,and now its seem to
Getting more worst!!! :'(

I can't use my tab unless I plug in the charger, or else it won't switch on! When unplugged it,my tab auto shut down and won't turn on until u press the power on button and quickly connect the charger...

(using it now with charger on!! :'( ) if there's anyone know what's the real problems here pls HELP ME!! and pls share with me how to stock back from cm10.1 to GB STOCK??? I really feel so desperately now!! :'(

Thanks in ADVANCE!!!
 

majzok

New member
Oct 26, 2009
3
1
0
Same problem here, did all the process including the correct permissions etc.. and appear battery stucked and then dark blue screen.

I am using samsung galaxy trand, as happens to your galaxy tab 2, seems our OS version 4 does something before playlpm or does not work, or am I wrong?

please help
I got it working on tab 2. Here what I did:
1. Install stock 4.0.4
2. Install NoMoarPowah! apk
3. edit file like in first post
 
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SadamHu

Member
Aug 15, 2012
14
1
0
Hi there, I'm a noob! I have a rooted Galaxy Note (first one), how do I write this script? Do I have to make a file and inside the file just write that text in there? And is that all I have to do to make my phone autoboot on charge?