Quote:
Originally Posted by knc1
The screen saver is no indication that the device is asleep. "Idle" == No work to be done, as in "idle loop" (which in modern devices isn't a loop at all). "Sleep" == Read the ARM manual to see what that means - there are many individually controlled areas of the SoC chip.
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Got it. Now we're heading back to my previous understanding of Kindle power states. I think I've read that a Kindle running on batteries generally goes to sleep a minute or two after the screen saver kicks in. But I haven't tested that.
Quote:
Originally Posted by knc1
It is your project, who did you expect to do the work?
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Me of course! But I figured getting some opinions from subject-matter experts BEFORE starting work was a wise thing to do. If you for some reason need info about hacking or programming an old REX 6000, I'm you're guy, and am happy to reciprocate, including battery questions!
Quote:
Originally Posted by Cinisajoy
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Cheapest and also isn't a battery, only a battery case (you supply your own 18650 even though the listing tries to imply otherwise). ;-) But point made anyway! I have lots of portable power, but it is a lot of complication I'd like to avoid. Why? More equipment for one, but also I think a good number of devices will be unplugged by players and not replugged in and I don't want device batteries dying at inopportune times. (I'm hope to use these devices to
streamline things during events for all involved. Extra complication of charging at night isn't an issue since it isn't happening during the event).
Quote:
Originally Posted by Yourcat
@xor: I have no idea whether meta refresh works in the kindle browser. If it does (or js.setTimeout) you may need just a simple to keep the Kindle alive by resetting the sleep timer and you may run your test with wifi enabled for some hours ....
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Yeah, hoping that simply hitting the "disable screen saver" option also disables sleep state. Will be testing that. Screen refreshing will be done via JS using data retrieved with an Ajax call, so I won't rely on meta refresh.
Quote:
Originally Posted by Yourcat
"I haven't jailbroken my kindle, but I assumed I could SSH into anytime after I "turned it on" " - I hope you learned that JB is required for SSH.
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Yep. And I did jailbreak the Kindle last night (first one ever! yay!). It was surprisingly easy, which is a testament to the work that other forum members have done to make it so!
Quote:
Originally Posted by Sukarn
Why do these things matter? To try to figure out whether his web app would *theoretically* use similar amount of battery to typical reading, or whether it would kill the battery by keeping the device awake when normal reading sends the device to sleep.
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Yep, on this and the rest of your post. Those are the sorts of things I was trying to asking about, not wanting anyone to test something for me, just get an idea of when my sort of app might be feasible.
I think this discussion, despite its enlightening meandering, has revealed that in my case it's not clear cut so testing is the only way to know.
Quote:
Originally Posted by knc1
If there is power on the USB cable jack, then the Kernel sets a "Wake Lock" flag and the Kindle never goes to sleep (although it can shift to another clock speed - depends on how you have its governor set). There is a KUAL app for that.
Even with the "Wake Lock" flag set - the Kindle can go into "Screensaver Mode" and display a screensaver.
But it remains running.
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Great info there. Thank you. And if power budget turns out to be marginal after my testing, you just gave me an idea that I might be able to save a bit by deliberately underclocking (assuming I figure out how that's done and performance is still acceptable).
Thanks all! Now I move on to battery testing. If someone has thoughts on questions 2 or 3 in the OP, I'm all ears!