Breakout Box Idea

[jamesthejust]

A breakout box that replaces the GP2X's battery cover (and coveres the back of the device) that holds an aditional 2 batteries and a 1.8" hard drive? A short moulded cable could connect it to the EXT port.

 

[BenScar]

It's possible...
Could even form it so that the 2x "sits" on it, like a docking station.

Thought about this myself, just finding time to get drilling and forming (although I was thinking more that in my case the HD would be a simple 2.5inch USB thingy)

But yes, I guess it's possible

 

[Squidge]

Well, if your going to replace the battery cover, you could replace the 2xAA batteries with a li-ion or polymer battery of 3.7V also, and then that would give you room to place a small circuit in the battery compartment too, and because of the 3.7V, you wouldn't need to step the voltage up, so the 2x wouldn't draw so much current in stepping that up, giving the end result of not needing quite so much battery capacity for the same life.

Or perhaps you could sandwich two batteries together in the same space as 2xAA, and use one of those to power the usb host or harddisk, and therefore only having a small bulk on the back of the device for the harddisk.

The possibilities are endless...

 

[chunkyktr]

"....you could replace the 2xAA batteries with a li-ion or polymer battery of 3.7V also, and then that would give you room to place a small circuit in the battery compartment too, and because of the 3.7V, you wouldn't need to step the voltage up, so the 2x wouldn't draw so much current in stepping that up...."

could you please clarify that a bit more for a electronics noob?

@BenScar... yet another use for polymorph!!

 

[BenScar]

@BenScar... yet another use for polymorph!!

Indeed! Still working on it's "current" form for now though.

The electronics thing.. The "li-ion or polymer" are different types of battery, they output a slightly higher voltage than the 2x normally uses. With the raise in voltage the unit will draw less current. This means the batteries will last longer, which is always good

 

[chunkyktr]

so would it be ok to pump 3.7v straight into the 2x, or would it need to be stepped down to 3v via circuitry?

the bit i'm mainly wondering on is squidge saying "you wouldn't need to step the voltage up", do i take it that the majority of the 2x circuits run on more than 3v?

sorry for the electronics noobness

 

[BenScar]

@Squidge have you got that list of Voltage vs Current drawn handy?
If I remember it went up to 3.7v (and above) without frying your 2x didn't it?

@chunkyktr the 2x runs off what ever batteries you put in it, as far as I'm aware there's no step up (or down) within the unit itself. So to answer your question, yes you could pump 3.7v straight in, although I take no responsibility on that one
(and don't worry about the electronic noobness, we all start somewhere)

 

[chunkyktr]

thanks for that BenScar. the theory side of electronics and circuitry is my weakness (i.e. my memory is shit). i need to get some basic reference books me thinks, any recommendations?

i might have a go at something like this as i've got my polymorph skills well honed now, but need to finish my b.o.b. dock first, and then my travel speaker hybrid...the list goes on

 

[Dimacus]

Well putting in a voltage regulator wouldnt hurt anyway
I found one that looks promising (using 3xAAs):
http://www.elfa.se/pdf/73/732/07328450.pdf

Vout is typicaly 3.3v and dropout is 0.32v @ 1.2A
Meaning, that instead of a max of 2.4v we get 3v!

But if we like to add a lithium battery, that's possible too.

 

[BenScar]

thanks for that BenScar. the theory side of electronics and circuitry is my weakness (i.e. my memory is shit). i need to get some basic reference books me thinks, any recommendations?

Sadly it's been a long while since I did any actual studying of electronics (which is why I'm goggling som thigns about current at the moment!), so no, no book recommendation, sorry.

but need to finish my b.o.b. dock first, and then my travel speaker hybrid...the list goes on

Doesn't it always? I want to finish re-learning my C++, then SDL, also Linux and more ASM and...... The list goes on

Well putting in a voltage regulator wouldnt hurt anyway

Indeed you're right there... There are one or two 3.3v regulators that are able to deliver 1A, just seems my local Maplin never have any in stock!

 

[GeminiDomino]

thanks for that BenScar. the theory side of electronics and circuitry is my weakness (i.e. my memory is shit). i need to get some basic reference books me thinks, any recommendations?

The Bible -"The Art of Electronics" By Horowitz and Hill. Try to find a used copy, this book is insanely priced (but worth it)