New hack to save battery while not using kindle5

[ramast]

When you turn off your kindle by pushing the power button once, it remain running for little bit then raise "ReadyToSuspend" event a little bit after that your kindle goes into sleep mode to save your battery.
Problem is, applications running on kindle can receive the event and request that kindle remain running.
for example if amazon is downloading an update and doesn't wish to be interrupted

the script simply force the kindle going into sleep mode whether the running software liked it or not.

Change log:
* Battery saver is now more aggressive.
It no longer waits for "ReadyToSuspend" signal instead it put the device in sleep mode one minute after turning it off.
That behavior might not be desirable to many since any background operation happening at that time (book being downloaded, system update being downloaded, kindle syncing, ...) will be suspended

* Kindle wakeup when I unplug it from usb cable, and so script has been updated to also put it in sleep 1 minute after unplugging it (but only if its locked!)

Known issues:
Kindle doesn't come out of sleep if it enters sleep mode while there is an active ssh session, you will have to power it off then on again

I own kindle white for a while and noticed that when I turn it off (by pushing the power button) kindle doesn't really turn off it just turn the light of the screen off, show nice screen save and continue running.

I knew for sure its running when I installed usbnetwork and was able to access my kindle through wireless connection while it is supposedly turned off [ shocking ! ]

Anyway I've wrote this simple application which check every 10 minutes [ crontab job ] whether your kindle is turned on or off, if turned off the program put your kindle into sleep mode.

While in sleep mode your kindle will no longer be activated when you plug it into usb and you will have to activate it manually by pushing the power button.

the program put your kindle into sleep mode by issuing the command
echo "mem" > /sys/power/state
That also means you no longer have to worry about turning wifi off before switching kindle off

Notes:

This script is working fine for my kindle paperwhite but I take no responsibility for any damage that might cause to any one try this. USE AT YOUR OWN RISK!

The install script do many validations before doing the actual install to ensure it will not fail.
install log can be found in the root of your sdcard

Install will fail if you tried to install the program twice.
uninstall script is included

EDIT: updated the package to be upstart service instead of cron, Thanks Dsmid for your code contribution and suggestion.
EDIT2: If you have installed the original script, uninstall it before - or after doesn't matter - installing the new script
EDIT3: Fixed a small bug when handling lipc error. no need to uninstall the previous - upstart based - version before installing this one

[ramast]

I take back what I said earlier.
Connecting your kindle to usb does awaken it from sleep mode.

best way to test is to have an ssh session to usbnetwork - either through usb or wireless -
turn off your device - by pushing the power button - and your session should still be working normally but within 10 minutes it should freeze

[knc1]

Originally Posted by ramast

I take back what I said earlier.
Connecting your kindle to usb does awaken it from sleep mode.

Of course.
An obvious OS design requirement.

While system is suspended, it has stored hardware setup data, including system bus information.

If you change the system bus configuration, that stored setup data would no longer match the hardware.
So the system comes out of suspend to account for the hardware changes.

[Antoinekamel]

Any like, statistical, result?

[ramast]

I've just wrote and tested the application yesterday.
usually my kindle would consume most of its battery within 3-4 days if wifi is on.
I left it on and will see how long is it gonna last.

And knc this is not always the case, my laptop would turn off its usb port so it doesn't get out of its suspense mode when a new usb is connected

[knc1]

Originally Posted by ramast

I've just wrote and tested the application yesterday.
usually my kindle would consume most of its battery within 3-4 days if wifi is on.
I left it on and will see how long is it gonna last.

And knc this is not always the case, my laptop would turn off its usb port so it doesn't get out of its suspense mode when a new usb is connected

And you are running Linux on your laptop ?
Which version of kernel?
Which distribution or home-rolled?
What make/model of laptop?

- - - -

Plus - the topic was Embedded Linux on the Kindle, not Linux on your laptop.

[ramast]

I am using gentoo linux, will send you a private message to keep this topic for its original prupose

[ramast]

After 5 days of not using my kindle - except for checking its battery everyday - here is a screenshot of how much battery has been used.
please note that during the test my wireless was on and aireplane mode was NOT activated at any point.

If it is to continue on this rate I would estimate at most 15% battery decline in two month provided the kindle is never used of course.

[dsmid]

Wouldn't this simple upstart script be better than fiddling with cron ?

/etc/upstart/battery_saver.conf

start on framework_ready
stop on stopping framework

respawn

script
    while true
    do
        lipc-wait-event com.lab126.powerd readyToSuspend || true
        echo "mem" > /sys/power/state || true
        # Gives us some time to react if something goes wrong
        sleep 60
    done
end script

[ramast]

its not a bad idea but, you need to give some time for the screensaver to work before initiating the sleep command

[dsmid]

Nope, readyToSuspend is fired when the device is already in screensaver mode for some time (about one minute).
I've tested that on my PW2.

See https://www.mobileread.com/forums/sho...61#post1689961

[ramast]

Awesome I will update the package and test it with the new code.
shall I use "dsmid" to address you in the source code?

[dsmid]

Originally Posted by ramast

shall I use "dsmid" to address you in the source code?

Sure, you can.

[Akirainblack]

Will this work with the PW2 or is it solely for the PW?

[ramast]

Akirainblack, I compiled the package to support AW2 but whether it will work or not I am not sure.
If you want to volunteer and test it please go ahead.

although you might want to wait until I adopt the code of dsmid before testing