Power Questions

[sryidc]

Hello all i Just have a few questions for my first post:

i have all my emulators and games on a usb powered HHD and am just wondering if the pandora will be able to power it with the usb. and how much of a power drain it will be.

i know i could just use sd cards, but i have all my movies, music, pictures on the hard drive and would like to use it with the pandora.

 

[Squidge]

Harddisks normally come with there own power supply, as the 500mA provided by USB isn't enough for the surge current harddisks normally require to startup. So in that case, there will be zero power drain from the system itself.

 

[quartercast]

Harddisks normally come with there own power supply, as the 500mA provided by USB isn't enough for the surge current harddisks normally require to startup. So in that case, there will be zero power drain from the system itself.

Did someone say 'their'? Oh... they didn't.

 

[Squidge]

Did someone say 'their'? Oh... they didn't.

I can't be arsed with such crap as that, as long as people can read and understand my posts. Only the pedantic people on this board will get wound up enough to moan about it

 

[scarath]

please dont argue about correct word usage it may effect forum moral

 

[teggun]

please dont argue about correct word usage it may effect forum moral

We will take your post seriously only when you use correct grammar.

 

[hal9000]

Harddisks normally come with there own power supply, as the 500mA provided by USB isn't enough for the surge current harddisks normally require to startup. So in that case, there will be zero power drain from the system itself.

Actually, external 2"5 hard drive do not need extra power (at least some of them).

Of course, in this case, I guess there is no hope to make them work with GP2X.

 

[scarath]

QUOTE

We will take your post seriously only when you use correct grammar.


I hate to use web-comics to reference a point but you totally fell into that one

sorry couldnt resist bad grammar trolling

 

[Chip]

Hello all i Just have a few questions for my first post:

i have all my emulators and games on a usb powered HHD and am just wondering if the pandora will be able to power it with the usb. and how much of a power drain it will be.

i know i could just use sd cards, but i have all my movies, music, pictures on the hard drive and would like to use it with the pandora.

To actually answer your question - Yes, sort of.

In order to use any USB device that actually draws its power from USB (like your HD), you will need to use a powered hub.

 

[sryidc]

its a WD passport, a USB powered hard drive.

the pandora should be able to power the drive im just wondering how much the battery life will suffer from doing so.

 

[hal9000]

the pandora should be able to power the drive

What make you think that? I am no expert in Lithium batteries, but I would bet on the opposite.

My USB powered hard-drive works on my Dell laptop, but not on my old iBook G3, because it does not provide enough energy.

 

[Squidge]

Actually, external 2"5 hard drive do not need extra power (at least some of them).

A lot do not need extra power, but expect the host provide power out of the usb specification (eg. 800mA startup current).

Of course, in this case, I guess there is no hope to make them work with GP2X.

Errr, this is the Pandora forum?

its a WD passport, a USB powered hard drive.

the pandora should be able to power the drive im just wondering how much the battery life will suffer from doing so.

WD Passport? I've tried one of those before and it needed far more than the 500mA of the USB specification before it worked properly (800mA I seem to recall it needed). It may work correctly on a PC which ignores the current being used by a device, but don't expect it to work in all portable devices.

 

[geise69]

I didn't want to ask my question in a new topic and saw this one. I felt it kinda went along with what's being discussed here. I was wondering if the Pandora is going to have any Power Save feature. If I am not using the device for a couple minutes will it dim the lcd screen to save battery power? Will it have a sleep mode as a power save option. Just was wondering. Sorry if this has been stated before.

 

[Chip]

I didn't want to ask my question in a new topic and saw this one. I felt it kinda went along with what's being discussed here. I was wondering if the Pandora is going to have any Power Save feature. If I am not using the device for a couple minutes will it dim the lcd screen to save battery power? Will it have a sleep mode as a power save option. Just was wondering. Sorry if this has been stated before.

According to Craigix, Pandora will have 2 suspend modes, as well being able to fully shut down (obviously). You will be able to suspend to RAM (sleep) as well as suspend to disk (hibernate). Apparently the system RAM uses so little power in sleep mode that they are estimating the device could remain in sleep mode for several days before the battery runs out. It could obviously hibernate indefinitely.

Craigix has also expressed a desire to allow the user to determine which of these modes Pandora enters when the lid is closed or the power button pressed, just like a laptop.

 

[nihilon]

Has there been any clarification with regards to what type of battery(ies) (Besides the fact that it'll be a
Lithium-ion battery) will be used or is/are being considered in terms of power capacity and whether it'll
be removeable and easily replaceable or not?

And what type of duration are we hoping for? 5,6,7 hours between recharges?

Will it be possible to replace the battery while its connected to AC to preserve the RAM/RTC state or to swap in another battery for charging (i.e. hotswappable charging)?

Just curious...

 

[Squidge]

Has there been any clarification with regards to what type of battery(ies) (Besides the fact that it'll be a
Lithium-ion battery) will be used or is/are being considered in terms of power capacity and whether it'll
be removeable and easily replaceable or not?

Yes. As big as can fit in the case comfortably, last as long as possible, and yes, it'll be removable and replaceable.

 

[Chip]

Has there been any clarification with regards to what type of battery(ies) (Besides the fact that it'll be a
Lithium-ion battery) will be used or is/are being considered in terms of power capacity and whether it'll
be removeable and easily replaceable or not?

And what type of duration are we hoping for? 5,6,7 hours between recharges?

Will it be possible to replace the battery while its connected to AC to preserve the RAM/RTC state or to swap in another battery for charging (i.e. hotswappable charging)?

Just curious...

There has been some discussion on all these points, but little is 100% definite. The battery will be a custom Li-ion pack, but only because there is no such thing as a "standard" Li-ion pack. Additional packs will be available if you wish to have extras. The original plan was to house the battery behind a panel which was to be held in place with one or more small screws. There was some disagreement on this point, some saying that this made on-the-go swapping very difficult. Craigix's argument for the screws was that easily removed battery covers are easily lost battery covers, but he admitted to be considering the options. In either case, the battery will be easily user-replaceable.

There has been no final word on battery life. I suspect that this is an impossible statistic to know for sure until the hardware is finalized and a pre-production unit is actually tested. As far as anybody here knows, this has not yet happened.

Pandora will definitely allow a battery hot swap while plugged in (as per Squidge, I think). It will also have a hibernate (suspend to disk) mode, which will allow a luke-warm swap when external power is not available. Although nobody has confirmed 100% whether the RTC will have some kind of backup for time retention during battery swap, I would be extremely shocked if this were not the case.

 

[nihilon]

Has there been any clarification with regards to what type of battery(ies) (Besides the fact that it'll be a
Lithium-ion battery) will be used or is/are being considered in terms of power capacity and whether it'll
be removeable and easily replaceable or not?

And what type of duration are we hoping for? 5,6,7 hours between recharges?

Will it be possible to replace the battery while its connected to AC to preserve the RAM/RTC state or to swap in another battery for charging (i.e. hotswappable charging)?

Just curious...

There has been some discussion on all these points, but little is 100% definite. The battery will be a custom Li-ion pack, but only because there is no such thing as a "standard" Li-ion pack. Additional packs will be available if you wish to have extras. The original plan was to house the battery behind a panel which was to be held in place with one or more small screws. There was some disagreement on this point, some saying that this made on-the-go swapping very difficult. Craigix's argument for the screws was that easily removed battery covers are easily lost battery covers, but he admitted to be considering the options. In either case, the battery will be easily user-replaceable.

There has been no final word on battery life. I suspect that this is an impossible statistic to know for sure until the hardware is finalized and a pre-production unit is actually tested. As far as anybody here knows, this has not yet happened.

Pandora will definitely allow a battery hot swap while plugged in (as per Squidge, I think). It will also have a hibernate (suspend to disk) mode, which will allow a luke-warm swap when external power is not available. Although nobody has confirmed 100% whether the RTC will have some kind of backup for time retention during battery swap, I would be extremely shocked if this were not the case.


I think something which snaps flushed with some sort of friction locking should be okay, maybe a slid catch for the cover so it can't slip away?

I wasn't aware of the hibernate feature, that's great! I use that often when logging off instead of a normal shutdown; saves looaads of time in bootup.

What you said about the backup for time retention is one of the things I was more curious about as well. It would be nice to a small CMOS-like battery or something equivilant (a small capacitor maybe?) so we wouldn't have to worry about resetting the clock and any other soft settings during swaps.

 

[Chip]

What you said about the backup for time retention is one of the things I was more curious about as well. It would be nice to a small CMOS-like battery or something equivilant (a small capacitor maybe?) so we wouldn't have to worry about resetting the clock and any other soft settings during swaps.

A RTC uses such a minuscule amount of power that even a tiny cap can keep it going for quite a while. I do not know the exact power requirements of the chip used in this particular SoC, but a quick google search found a similar type of RTC IC requiring only 300nA. That's an "n" as in nano, as in 300 billionths of an amp at < 2V.

I think it's safe to assume a capacitor backup will be present to maintain RTC function during battery swap.