difference between shutting down and screensaver

[alansplace]

Originally Posted by HarryT

The reason I say "I speak from personal experience" is that I needed to reboot my Kindle last week (the web browser started doing funny things), and that's exactly what happened to me. I held in the power switch for a long time, the screen flashed white, and I let the switch go, expecting that it would reboot. It didn't. It was only when I pressed the power switch again that it booted, and it was a full reboot, with the tree, etc. So, I really don't know HOW it happened, but happen it assuredly did.

Originally Posted by l_macd

Well I've had fun today trying different variations and it's worked differently every time.... when I tried to reset it earlier, it worked just the same as you described HarryT, it switched off and I had to press the power button to turn it back on, then it went through the full reboot.

I then tried holding it for little longer (20 seconds), this time it did reset on it's own. I've just tried it again now and whereas before when I held it for around 12 seconds it just went to sleep with a blank screen (resumed within seconds), this time it reset again. When I hold it for 7-10 seconds it goes to sleep with a blank screen.

One good thing with all this fiddling around with the on/off button, it had previously felt a bit spongy, now it slides along easily the same as the other Kindle we have

i've tried it in 1 second increments from 12 to 20 seconds it never shuts off. i'm tired of trying.

[teasonc]

Kindle never shuts off.*1

All the microprocessor needs to do is detect activity on the slide switch. The act of sliding it wakes the micro, which begins measuring how long you hold the (spring-loaded, momentary-contact) switch.

____
*1 The two Kindles I own never shut off .. with caveats.

Please see:

https://www.mobileread.com/forums/sho...d.php?t=113709

12-29-2010, 11:33 PM #1
thatsme
Bypassing the screensaver entirely on suspend


https://www.mobileread.com/forums/sho...01&postcount=8

08-05-2011, 01:00 PM #8
fbdev
how to tell when kindle sleeps/wakes up

[max99]

Originally Posted by l_macd

1. Slide and release puts it to sleep with screensaver.
2. Slide and hold for 7 seconds, puts it to sleep with blank screen.
3. Slide and hold for 15 seconds turns it off.

1 & 2 doesn't use any battery life after it's been put to sleep, the screen resumes within seconds and only uses minimal battery when doing so.
3 doesn't use any battery life after it's been turned off, but it takes a while to load (the tree screen appears at this point) and uses up considerably more battery when doing so.

1 and 2 are totally different modes and draw different amounts of power. how do i know this? if you install 3.2.1 firmware on kindle dx, mode 1 will take over 15 seconds to wake up from whereas it only takes 4 seconds to wake from mode 2.

both modes 1 and 2 retain memory contents so the cpu must still be running. probably the difference between them will be wifi/3G...maybe mode 2 switches radio functions off.

[teasonc]

Hi max99,

Mode 3 does not exist, in my opinion. I don't see any evidence supporting the existence of it.*1

i.e. I concur with Alan's last paragraph, in #10 (above).

I'm working on the assumption that once you walk away from the Kindle, 22 minutes later, everyone is in the same state (call it 'deepest suspend').

How you got there is by the path you took to reach it.

What I want to know is, what does it 'suspend to'?

In usual parlance, it's 'suspend to disk' and implies storage. That's what I want to know about -- where it suspends 'to' .. what gets written, to what media/storage. That's the hot question for me.

I think that people who flicked the slider switch for around one-half to one full second got there with a delay of ~2 minutes. They invoked the 'light sleep' mode, which has a two-minute timeout before going into 'deepest suspend' mode. During those two minutes, the password-request dialog presents instantly, when requested with a quick slider switch actuation.

People who held the slider for about 13 seconds (depending perhaps on the model and firmware) got there (to deepest suspend mode) in 3-8 seconds after letting the slider switch relax to its return position on the spring-loaded mechanism. Also their screens turned all-black, for a moment, and their machines rest with blank screens, while they're suspended.

It took 3-8 seconds for the machine to go into deepest suspend, I'm conjecturing. These people will notice a countable delay when they awaken the machine, and are in the same state as the light-sleepers, two minutes on.

Seems to me that recovery from 'light sleep' is almost instantaneous. But. If you wait just two minutes, no matter how it went to sleep (on a timer, or by your action) .. it then takes a few seconds to awaken. To me that's a sign that the system suspended fully (regardless of what's on the screen, an image or blank).

The 22 minute figure derives from 20 minute idle timer that invokes the light sleep, plus the 2 minute timer then invoked (call it the 'last chance' timer) that puts it into full suspended mode.

So in my theory, from a battery savings point of view, anyone with a screensaver showing is only 2 minutes away from the best possible savings in battery charge -- and they only gain two things by holding the slider down long enough to blank the screen (deep suspend):

1. They hit deep suspend 2 minutes sooner than the other guy;

2. They *might* experience some favorable (or unfavorable) long-term consequence to the eInk display, due to -- whatever voodoo you think may be going on with it, if it sits there hour after hour without Virginia Woolf displayed.

There's some speculation there are other benefits to invoking deepest suspend, by command of the slider switch. I was myself under the impression this method conveyed significant battery-charge preservation. Now I'm not so convinced that is the case.

____
*1 I cannot speak of Kindles I have not personally inspected. Therefore, my statements only apply to my own devices, here in my home. I'm wondering if there can be differences, due to firmware revision, or date of manufacture of the device.

[Kevin8or]

Originally Posted by teasonc

They *might* experience some favorable (or unfavorable) long-term consequence to the eInk display, due to -- whatever voodoo you think may be going on with it, if it sits there hour after hour without Virginia Woolf displayed.

There's some speculation there are other benefits to invoking deepest suspend, by command of the slider switch. I was myself under the impression this method conveyed significant battery-charge preservation. Now I'm not so convinced that is the case.

I'm eager for this kind of information. The existence of a deep suspend mode implies that there are circumstances under which it's more beneficial to use it than the quick sleep mode. At least, somebody on Kindle's design team thought so. Why? When? And while we're at it, what's the ultimate answer to the ultimate question of life, the universe, and everything?

[gweminence]

Kindle only uses power when turning the page. Leaving it 'on', for the 10 minutes that it takes to go into sleep mode, consumes no power.

[max99]

Originally Posted by gweminence

Kindle only uses power when turning the page. Leaving it 'on', for the 10 minutes that it takes to go into sleep mode, consumes no power.

wrong. it consumes about 23mA even when idle with radio off. some guys did some diagnostics on another thread. the cpu is operating at full power when it isn't asleep.

that's why if you invoke the screensaver disable from the debug mode your kindle will only last about 4 days before going flat.

[teasonc]

The system log, /var/log/messages, seems to get rewritten in conjunction with suspend events. I've seen two variations of this already.