Rockbox General > Rockbox General Discussion

Save iPod battery life by turning off in Apple OS?

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Llorean:
The reason has been discussed in many places, we've made no secret of why we don't include it yet. Please use the search feature, as per the posting guidelines.

In fact, go and read them now, it seems you've forgotten a few of them.

It really doesn't matter if you're sure it will happen with the official build or not, unsupported builds are running older code, and have different code, so they can have completely different causes for the same problems.

countach:
Ok, let me apologize for my laziness about finding the reason about the album art issue. I've made now a deep search and I found a lot of people asking the same, and I think this thread explain pretty well the situation:

http://forums.rockbox.org/index.php?topic=9392.0

In a few words, I understand that the RB team is not happy about the quality of the current art solution and the one that would be (if so) will be different. Great news, so let's wait.

About the posting guidelines I've readed them again and aside the non-sopported build question, (for wich one I apologize, in fact, i always used its thread to discuss issues about the build), I think I'm following them. As a non-english speaker, maybe my text is weird sometimes, but I try to keep it clean...



So, returning to the topic, I will install the official build and will keep track of this self-startup thing, posting the results next week in this thread.

Again, thank you for the effort, I only want to contribute in any way I can. I'm a coder too, and for sure if I had time will be looking at the sources... in the meanwhile, I'm making some Themes.

TexasRockbox:
Some current is needed to keep the clock running and accurate also the on/off isn't like a physical on/off switch to connectg/disconnect the battery but instead senses on when a button is pressed.  That type of on/off takes continous current as well.

scharkalvin:
Some insight into battery powered devices from a software developer.....

Most computer controlled devices do not really power down but enter a VERY low power mode.  Depending on the hardware this can be somewhere between a few milliamperes to tens of microamperes.   The cpu makers call this mode 'power down', 'power save', or 'sleep' mode.  In the lowest power modes the cpu clocks stop completely and a few interrupt inputs are left armed.  The cpu comes back on line when an external interrupt is detected (from the user interface).  If time keeping is desired, an external cmos tod clock chip is used.  Higher power sleep modes just slow down the clock.  Since the usual clock speed used is in the range of megahertz to hundreds of megahertz a real slow clock rate of 32khz is sometimes used.  At this rate the cpu can keep track of the TOD, but not much else, but power consumption in this mode might be in the milliampere range.

Aside from the power down current drain we also have to worry about the batteries self discharge rate.  This is quite high for NiCads and Nimh types resulting in a shelf life of about a month or so (for AA size batteries).  LiIon types have a much lower self discharge rate and can hold a charge for a year or more.  But LiIon batteries can't be allowed to drain below a critical point or they will require reforming before they will accept a full charge again.  This makes a good battery monitor / smart charger circuit a critical part of any device powered by a LiIon battery.  As a result most LiIon powered devices do NOT implement the charger in software, a separate charger chip is used.

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