Use broken Pandora parts to build an external Pandora battery charger


hmc

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Dec 19, 2011
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Hi guys,


don't throw away cracked cases or slightly broken mainboards!


Even broken display cables and screens might still be useful.


They can be used to build an external spare battery charger for the Pandora.


Here are the details of my idea:


Take a Pandora case and a mainboard, as well as an AC adapter. Nothing else is required. No screen, speakers, buttons and keyboard mat.


Assemble mainboard and case, shut the case, turn the thing upside-down, connect the AC adapter.


Instead of a regular battery compartment cover, apply a small plate of metal or plastic in the range of the battery contacts, which holds the battery down, connected to the contacts, but allows easy insertion / removal of the battery, similar to the usual camera battery chargers.


I guess, the mainboard needs to have working CPU and RAM and Flash, because charging is controlled by software, right?


But if something else is broken, such as WiFi, keyboard contacts, SD slots, graphics chip or something like that, the mainboard may still be suitable for this purpose.


The firmware does not need to (or should not, because it needs so long to boot) be a full Zaxxon firmware, but some stripped-down Linux, just with suitable charging control, optimized for a short boot time and - maybe - for fast charging (5..10 sec boot time could be realistic).


As a bonus, the charging LED could be moved to the other side of the Pandora, facing up when the Pandora is turned upside-down.


In order to make firware updates possible without taking apart the entire thing, the firmware and bootloader might contain the ability to be controlled via serial port through the EXT connector (or via USB, and a working SD card slot may also be favorable then).


Alternatively, the thing could contain a keyboard mat and a screen, which is still able to display (but touchscreen ability may be broken; even the older broken display cables might be used, which cause the colors not to appear correctly; I had such cables myself, it's annoying for regular use, but here it wouldn't matter).


Comments?


If anyone is willing to donate such broken parts to me, I will be willing to invest some time to design such a thing and to document it.


For owners of multiple batteries, an external charger could be a great benefit.


And it can be a good playground for developers, interested in adding some fancy features to the charger, e.g. the ability to emitting funny noises, reflecting the battery charging state, or letting the thing speak the remaining time until the battery is full (but then a speaker will be needed) ;-)


Daniel
 
I would be interested to see how this turns out.


So what's the plan? Figure out how to make one yourself, create the DIY document, and then people who are interested can buy the parts they need from OPT and put it together themselves?


Seems a good idea and a way that OPT can recover a small amount of their losses...


Sent from my HTC Sensation Z710e using Tapatalk
 
I'd guess this would be a really expensive charger...


Better to harvest the main parts from the boards back. If a Pandora is functional, so that it can load an os and the firmware can be upgraded, it should be "too good" to be a charger.


Also the controlling of charging, that is done in software in the os so you need a pandora that can boot an os.
 
Yes, I understand your "too good" argument.


However, recent discussions about e.g. the 256MB boards seem to indicate, that people strongly want boards with higher specs, once they are available. So such a charger could also be a way to at least get some value out of the older boards.


Of course, selling them as cheaper entire Pandoras would even get more value out of them. I don't know about the demand for both alternatives (low-spec Pandora / Exterrnal charger).


Anyway, there may be people like me, who really like to have an external charger, and for those, such a project may be interesting, even if it's not that cheap.


But of course, if building such an external charger would mean wasting parts of good value for a "lower" goal, and thus maybe even hurting the Pandora project, because those parts would be missing in a place where they would be needed more badly, it would not be a good idea.


I'll discuss this with ED soon. (Or, if you are reading this, ED, I'd appreciate your comment here, too!)


Daniel
 
I still think that you can have a cheaper external charger with a normal power supply and a chip, that monitors the voltage in a small box without the whole Pandora pcb etc.


Edit: of course there already are prebuilt LiPo Battery chargers for RC batteries for around 30 Euros. You would just need the proper connectors for the Pandora battery.
 
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