Usb -> Power Gp2x

[Wombat]

Hi all,

I've just got my GP2x (waiting for batteries to charge )

I cant seem to find any relavent topics in here, but I was wondering....

Would the 500mA from a PC's usb port at 5V regulated to 3V be enough power to subsitute the GP2x's PSU Adapter?

I'm thinking of making such a cable, saves carrying around an adapter (when they're all back in stock!) as well, plus it could all fit in the carry case.

TIA
Wom.

 

[Epicenter]

Technically you need 3.3v anyway... If it works, it'll be very unstable. It might work alright if you underclock to below 100 MHz. Forget about playing any video that is not exactly 320x240, using emulators that do hardware scaling of the display, or TV-Out. The scalers and TV out hardware suck power like there is no tomorrow.

 

[Wombat]

Technically you need 3.3v anyway... If it works, it'll be very unstable. It might work alright if you underclock to below 100 MHz. Forget about playing any video that is not exactly 320x240, using emulators that do hardware scaling of the display, or TV-Out. The scalers and TV out hardware suck power like there is no tomorrow.

Hmmmm ok what about this way
Double headed-usb cable, total would be 1000mA 10V...

 

[Epicenter]

Hmmmm ok what about this way
Double headed-usb cable, total would be 1000mA 10V...

I'm pretty sure that's 100mA per port, not 500mA.

 

[Wombat]

Hmmmm ok what about this way
Double headed-usb cable, total would be 1000mA 10V...

I'm pretty sure that's 100mA per port, not 500mA.

hmm my current usb usage says i have 9 ports avail, total power per port is 500mA, currently only using 400mA (USB Mouse & Keyboard).

I'll try an old double header cable I have laying around and see how much I can draw off it, prob best bet.

If this works, would be a nice alternative to the PSU adapter

 

[krosfyah]

It does sound like a cool idea but I think you'll find yourself using batteries even when you're near a power source.. why? because the power input on the GP2x is in the most retarded place ever and makes extended gaming quite difficult, not to mention painful.

 

[Epicenter]

hmm my current usb usage says i have 9 ports avail, total power per port is 500mA, currently only using 400mA (USB Mouse & Keyboard).

I'd love to know where you are reading this...

 

[Wombat]

hmm my current usb usage says i have 9 ports avail, total power per port is 500mA, currently only using 400mA (USB Mouse & Keyboard).

I'd love to know where you are reading this...

Direct from my PC (albeit the WinBlows one )

Gentoo one is updating so not ready yet...

P.S even tho its says hub, its all onboard.

 

[BradN]

All I've ever heard was 500mA at 5V. With a highly effecient 5V -> 3.3V step down converter, it should be workable.

 

[Wombat]

Also can anyone tell me how long to leave these ansmann 2600's on charge (www.gbax.com batts+charger), they've been on about 9 hours now and lights still on, on the charger.....????

 

[mrsnature]

Also can anyone tell me how long to leave these ansmann 2600's on charge (www.gbax.com batts+charger), they've been on about 9 hours now and lights still on, on the charger.....????

Don't know what charger that is, but what current does it supply? (probably written on the charger). If its not one of these 'super duper fast' chargers, 9 hours isn't too bad...

If its a clever knows-when-the-batteries-are-full chargers try unplugging it and replugging it, or just use the batteries now and see if they charge up probably next time.

 

[Nighty]

Technically you need 3.3v anyway... If it works, it'll be very unstable. It might work alright if you underclock to below 100 MHz. Forget about playing any video that is not exactly 320x240, using emulators that do hardware scaling of the display, or TV-Out. The scalers and TV out hardware suck power like there is no tomorrow.

Hmmmm ok what about this way
Double headed-usb cable, total would be 1000mA 10V...

I hope you're just joking, and I don't get it...

You'll get 5V, 1000mA using both ports in parallel. I'm not sure if using them in series is possible, but in that case you would get 10V, 500mA.

Anyway, using the power of two USB ports, you'd be able to power the gp2x comfortably; using only one will probably make the unit hang often during moments of peak power drainage; after all, the back of the unit says 3.3V 1A. Even with perfect conversion you can only get 757 mA out of one USB port when converting to 3.3V (assuming perfect conversion with no energy loss due to heat and other crap). The 1000mA will have some safety margin calc'd in, but not 1/3rd of the actual needed current.

 

[Wombat]

I hope you're just joking, and I don't get it...

You'll get 5V, 1000mA using both ports in parallel. I'm not sure if using them in series is possible, but in that case you would get 10V, 500mA.

Anyway, using the power of two USB ports, you'd be able to power the gp2x comfortably; using only one will probably make the unit hang often during moments of peak power drainage; after all, the back of the unit says 3.3V 1A. Even with perfect conversion you can only get 757 mA out of one USB port when converting to 3.3V (assuming perfect conversion with no energy loss due to heat and other crap). The 1000mA will have some safety margin calc'd in, but not 1/3rd of the actual needed current.

Soz yeah I meant as in parallel, only way to get 1000mA, i'll try it at work tomoz when I get some free time hopefully my batteries will of charged by then lol.