Mk2 With Extra Voltage On Ext Port

[nubie]

Does that mean I can do THIS:

If internal batteries then YES, YES, YES!!

Where and how much, is it flash based? What batteries does it take and how long do they last.

Likely all you will need is this circuit, it will be small enough to fit in the connector at the EXT port.

 

[Epicenter]

In case you didn't notice, that was a mp3 player.

It looked like one of those bulbous models with a laptop HDD. The USB cable comment made it even more confusing. My bad. At any rate, no, it is probably not powerful enough to operate that Mp3 player .. and the microdrive or similar it has inside.

 

[invinciblegod]

Does that mean I can do THIS:
IPB Image

If internal batteries then YES, YES, YES!!

Where and how much, is it flash based? What batteries does it take and how long do they last.

Likely all you will need is this circuit, it will be small enough to fit in the connector at the EXT port.

well when I got it it was $120 after rebate. I got it last august so it should be cheaper now. It is hard drive based and the battery seems to last at least 10hours on playing but if you are copying files and really using that hard disk, I'd say more like an hour or so (you can just copy it to your sd card anyway). It takes a custom battery (probably li ion).

In case you didn't notice, that was a mp3 player.

It looked like one of those bulbous models with a laptop HDD. The USB cable comment made it even more confusing. My bad. At any rate, no, it is probably not powerful enough to operate that Mp3 player .. and the microdrive or similar it has inside.

Well it does have its own battery.

 

[jokeman]

Yes, low current devices work, there are schematics on the wiki for 3v to 5v step-up.

is this really a 3v to 5v stepup?
i think, there is an error in the header, because this circuit takes 6-20V in and not 3V in.
it looks more like a 6V+ to 5V regulator to me.

 

[nubie]

Yes, low current devices work, there are schematics on the wiki for 3v to 5v step-up.

is this really a 3v to 5v stepup?
i think, there is an error in the header, because this circuit takes 6-20V in and not 3V in.
it looks more like a 6V+ to 5V regulator to me.

Good question, does anyone know what the voltage on the Mk2 is supposed to be?

If it is higher than the Mk1 at the EXT, how did they do it?

 

[BradN]

Personally I don't think they would have changed the voltage, because it would require them adding additional step-up circuitry, and that's another couple bucks you just don't wanna spend on something like this, not to mention board space.

What's possible is they've changed the step-up converter to be able to supply more current, which would be able to power more USB devices directly, provided you're still using an external step-up converter. It could be a consequence of whatever converter they were using being a little marginal (some units wouldn't run except on AC, etc), so perhaps they replaced it with a better one just to be on the safe side.

And besides, it would make EXT port peripheral development a little trickier if you don't know what voltage it will be supplying (3.3V vs 5V).

 

[kardasan]

Yes, low current devices work, there are schematics on the wiki for 3v to 5v step-up.

is this really a 3v to 5v stepup?
i think, there is an error in the header, because this circuit takes 6-20V in and not 3V in.
it looks more like a 6V+ to 5V regulator to me.

True. Maybe he thought about levelshifter based on MAX3232, but it's only used for serial port.

 

[nubie]

True. Maybe he thought about levelshifter based on MAX3232, but it's only used for serial port.

I designed the Samsung e810 mod using the integrated 232 level shifter in that cable.

I know what I am talking about. I am talking about this:

http://wiki.gp2x.org/wiki/USB_Host_BoB_Schematic

Under the caption "VUSB Boost from 3.3v to 5v:" on the page above I found this circuit:
http://wiki.gp2x.org/wiki/Image:Bob_vusb.png

I don't know what the deal is with that picture/caption, if anybody has any info feel free to correct me.

Please don't assume that I don't know what I am talking about, I have to provide these links and explain them every time I post about this (10 times so far) because nobody bothers to do their own research.

I suppose I should really draft a blanket statement and put it in my Sig, that way I can point people to the gp2x wiki hardware hacking pages, education is better than incarceration.

 

[BenScar]

Looking at that Wiki entry I think it's badly labelled.
The 7805 won't run off 3.3v to give 5v out (sadly!), the diagram is correct you need 6v+ to get that regulator to give 5 volts out (spec sheet is Here)

At least this is my understanding of the 7805 voltage regulator

 

[jokeman]

jes... nubie knows, what he is talking about... helped me with my serial cable too... (b.t.w. i should post my pics of the samsung cable in the wiki too)

but to the USB circuit... the header in the wiki says "VUSB Boost from 3.3v to 5v:" but it doesn't take 3.3V
so something is wrong... either the header or the voltage in the picture... but i think, its the header

 

[Ubersnug]

Considering how cheap 1gig + SD cards are these days is having the ability to use usb pen drives in our GP2X's really that much of a benefit? Especially having a big fugly pen hanging out of it?

Unless I'm completly missing the point here?

 

[weirdocollector]

Considering how cheap 1gig + SD cards are these days is having the ability to use usb pen drives in our GP2X's really that much of a benefit? Especially having a big fugly pen hanging out of it?

Unless I'm completly missing the point here?

True, but I was thinking about USB HDD (much more capacity then USB pens), and, above all, Wi-Fi of Bluethooth dongles B)

 

[DavidBeoulve]

I hope you got a deal on that 1GB stick, I was just in Best Buy and there was a 1GB stick for $44.95 on sale and an additional $10 mail-in rebate. $35

Uhhh yes. Because a friend got it for me for Christmas

 

[lintsniffer]

OWNED

I got a 4GB for $90, and its en route. I hope it works (ADATA 150x)

 

[nubie]

Considering how cheap 1gig + SD cards are these days is having the ability to use usb pen drives in our GP2X's really that much of a benefit? Especially having a big fugly pen hanging out of it?

Unless I'm completly missing the point here?

@Ubersnug, Look at this 20GB 1.8" Hard Drive for $99, that is why we need USB, and note it is 1.8", those are as long as the 2.5" ones are WIDE, very small, much cheaper than SD. And weirdocollector is right, we need our wifi, how else will people know to port web browsers?

Uhhh yes. Because a friend got it for me for Christmas

So I hope he got a good deal, or he can afford it, hey you are set to go, you don't even need an SD, but considering newegg.com has a lot of 2GB SD for $39 to $50 order one from here if you need an SD.

OWNED

I got a 4GB for $90, and its en route. I hope it works (ADATA 150x)

Nice deal, where did you get it? For those who want one: Newegg.com 4GB SD 150x $86.99 + 4.99 s&h

 

[dj-spuddy]

Looking at that Wiki entry I think it's badly labelled.
The 7805 won't run off 3.3v to give 5v out (sadly!), the diagram is correct you need 6v+ to get that regulator to give 5 volts out (spec sheet is Here)

At least this is my understanding of the 7805 voltage regulator

Actually I'm pretty sure it's 7 volts. Atleast I know this to be true on a normal 7805. However there are a few variations of the 7805 so the drop-out limit could be different. Also the max a 7805 can handle is about 35v. But it would cause so much heat it would probably melt.

 

[Epicenter]

The MegaDrive uses 2 7805s with 9V to produce 5V from each. These were made by Motorola.