K4 Extending/refreshing screensaver timer?

[nimbulan]

I've recently set up and old Kindle 4 (4.1.4) to act as a weather station, which seems to be a fairly common project. I am using the Online Screensaver Extension script (https://www.mobileread.com/forums/sh...d.php?t=236104) with the modifications to allow it function on Kindle 4 found in this post: https://www.mobileread.com/forums/sh...2&postcount=36

This works great...except that it only updates 4 or 5 times before stopping. Using the log file for the script, I was able to track down the problem:

Thu Feb 11 03:05:09 UTC 2021: wait_for called with 900, now=1613012709, Powerd state: Screen Saver, defer_suspend:0, Remaining time in this state: 53.913745, Battery Level: 58% Battery logging: On
Thu Feb 11 03:20:22 UTC 2021: wait_for called with 900, now=1613013622, Powerd state: Screen Saver, defer_suspend:0, Remaining time in this state: 41.375632, Battery Level: 56% Battery logging: On
Thu Feb 11 03:35:35 UTC 2021: wait_for called with 900, now=1613014534, Powerd state: Screen Saver, defer_suspend:0, Remaining time in this state: 28.618913, Battery Level: 56% Battery logging: On
Thu Feb 11 03:50:47 UTC 2021: wait_for called with 900, now=1613015447, Powerd state: Screen Saver, defer_suspend:0, Remaining time in this state: 15.851457, Battery Level: 56% Battery logging: On
Thu Feb 11 04:06:00 UTC 2021: wait_for called with 900, now=1613016360, Powerd state: Screen Saver, defer_suspend:0, Remaining time in this state: 3.076768, Battery Level: 56% Battery logging: On
Thu Feb 11 04:21:12 UTC 2021: wait_for called with 900, now=1613017272, Powerd state: Ready to suspend, defer_suspend:1, Remaining time in this state: 33.024700, Battery Level: 56% Battery logging: On

From these log entries, you can see that the "remaining time in this state" continues to decrease every time the Kindle wakes up to update the screensaver. Once the power state reaches "ready to suspend" the wifi no longer functions (and I'm not sure the screen can be updated at that point either.)

So I'd like to know if there's a command I can add to the script that would extend the time remaining in the screensaver state, or to refresh it somehow, so the script can continue running indefinitely without needing to keep it plugged in (since I understand that when plugged in, the Kindle will stay in screensaver mode indefinitely.) I am aware that the length of the time the screensaver is active can be modified through the t2_timeout setting, though no matter what value is set it would always be a fixed amount of time (also not sure if there's a maximum value.)

Any suggestions would be appreciated.

[mergen3107]

How do you set t2_timeout setting?
I dug up my K4NT notes and I can see that I couldn't get it changed by editing or replacing the file, and I needed to use command (example is for timeout before Kindle goes to sleep):

mntroot rw
kdb set system/daemon/powerd/t1_timeout 600
mntroot ro

[hius07]

More on t1_timeout
https://www.mobileread.com/forums/sh...d.php?t=127842
https://www.mobileread.com/forums/sh...d.php?t=271120

[nimbulan]

Originally Posted by hius07

More on t1_timeout
https://www.mobileread.com/forums/sh...d.php?t=127842
https://www.mobileread.com/forums/sh...d.php?t=271120

Ah thank you that second thread has some very useful information. This command looks interesting

lipc-set-prop com.lab126.powerd -i touchScreenSaverTimeout 1

which resets the timer to enable the screensaver while in active mode. Unfortunately I do not see an equivalent command for what I want to do, which is to refresh the suspend timer while in screensaver mode. There are a couple other commands that look potentially useful such as suspendGrace, and abortSuspend, but I'm not 100% sure what they do.

I am also seeing that you can simulate pressing the power button, so I could potentially just trigger the Kindle to wake up then go back into screensaver mode.

[nimbulan]

I seem to have found a decent solution here. The command

lipc-set-prop com.lab126.powerd -i abortSuspend 1

when issued during the "ready to suspend" state immediately returns the Kindle to screensaver state with the full timer length. Some quick changes using this command allowed the script to continue to function long-term, though it would have gaps with several missing updates. I'm working on the scheduling logic to improve the reliability, so this should hopefully be a robust and reliable solution when I'm done.