Making A Ext -> Usb Cord...


cwncool

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Jul 24, 2006
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i saw that torpor made an EXT USB host (here)and they are for sale at here. I don't want to buy one, I'd like to make one myself. Can someone please explain how I could build a cord such as this? Thanx! :)
 
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well, not that I could find. In "USB Host" I don't see any sort of instructions on how to build the physical cord. Where can I find some sort instructions on how-to? Thanx!
 
Vimacs posted on Jul 27 2006 at 07:36 PM said:
check the wiki, its all there.

What, no belittling remark? No closed topic? You're slipping man :lol:

(Edit: forgot the apostrophe)
 
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:D I seriously checked the wiki a few times over and I couldn't find anywhere that explained how-to make the usb host cord. Can someone help? :D
 
okay. i'm not planning on using a BoB. I want a cord with just the usb. Would I get a EXT connector from a S810 or something and then just hack up a usb extention chord so I only have the USB in. Then, on the back of the male EXT connector, solder the wires from the cord onto the the port 9 and 10 or is there more that would need soldering?

(lol. as you can tell, i'm gonna need some help :D )
 
that's to make it built in, but thinking about it, that makes it a little easier . :D Just using those principals but with an extra cord. Thanx! I'll look at that, but more suggestions are always needed :D :D
 
oh yeah, another question :) . How could I integrate a 9 volt battery into my cord to power whatever is being plugged in?
 
A 9V might not be able to provide enough amperage to run something like a hard drive (if it did, it certainly wouldn't last very long). I think a better bet would be something like 4 AA's with regulation circuitry (something capable of doing step-up if the voltage falls below 5V).
 
okay, but how would I integrate the four batteries and their little encasing into the usb cord? which wires of the cord would I connect the wires from the battery case to?
 
I think a project like that might be more involved than you want to deal with - you could get by with 4 batteries (or even 2, but the runtime wouldn't be as good), but you would have to do some custom electronics hacking to make a power supply out of them. The problem is the battery voltage will vary over a somewhat wide range as they discharge, and USB needs a constant 5V +- .25. So at that point, you need a regulator, and to run one off 4 batteries, it gets even trickier since it must be capable of boosting the voltage too (translation: you've gotta solder a whole bunch more crap).

The easier, but bulkier route, would be using 6 batteries and a simple 7805 type regulator that needs no extra components (but isn't very efficient). I think you'd really need a separate box of some sort to house the stuff.

Personally, if I were to go about doing it, I'd find a carrying bag that can hold the GP2X with some extra room for a hard drive and the batteries, and kind of build it all into that.

As far as which wires are for what... if you can't tell by looking at the diagrams, you should really find someone more experienced to help with those parts. Soldering on a tiny connector can be very difficult too (I wouldn't even trust myself doing it). By the time it's all done, you might as well have just bought a breakout board and hacked up a power supply for that.
 
i didn't want it for a harddrive though :) i was planning on using it with qtopia so I could browse the net with wifi and opera. a small usb wifi connector isn't gonna need much power ;) i just want to make something small similar to torpor's cord
 
cwncool posted on Jul 27 2006 at 08:40 PM said:
a small usb wifi connector isn't gonna need much power

Yes it will. It is unbelievable how much power those things use. They draw currents of up to 650ma.
 
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Ahh, I see. Well then maybe a 9V (or even 2 in parallel for longer runtime if it becomes an issue) and a 7805 would be more practical. A rechargeable "9V" is usually 7.2V and would be well suited to this, as extra voltage beyond 6-7V just generates more heat with a 7805. Capacities around 250mAH are typical for NiMH 9V's, so I'd make a rough guess and say it would last 1-2 hours, maybe more if it's a very efficient device and isn't transmitting much.

Edit: if jmetal88 is right, and they really do use that much power continuously (I think the USB maximum is 500mA though, but even that would be a lot), you may want to find another way than 9V's. A single AA NiMH stores more energy than one of them.
 
:) lol. i'm in way over my head. maybe after I get my gp2x i'll just pay someone to make one for me. :D
 
BradN posted on Jul 27 2006 at 09:34 PM said:
Ahh at I see. Well then maybe a 9V (or even 2 in parallel for longer runtime if it becomes an issue) and a 7805 would be more practical. A rechargeable "9V" is usually 7.2V and would be well suited to this, as extra voltage beyond 6-7V just generates more heat with a 7805. Capacities around 250mAH are typical for NiMH 9V's, so I'd make a rough guess and say it would last 1-2 hours, maybe more if it's a very efficient device and isn't transmitting much.

Edit: if jmetal88 is right, and they really do use that much power continuously (I think the USB maximum is 500mA though, but even that would be a lot), you may want to find another way than 9V's. A single AA NiMH stores more energy than one of them.

Usually, it's 650ma in full transmit, 500 something in full reciept, and around 400 when "listening".
 
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Wow, that's pretty pathetic. I can understand when transmitting, but it shouldn't need 400mA just to twiddle its proverbial thumbs.
 
jmetal88 posted on Jul 27 2006 at 07:45 PM said:
Usually, it's 650ma in full transmit, 500 something in full reciept, and around 400 when "listening".
If you check the specs on the chipset we actually have wifi drivers for you will see it is 150 listening and 450 on transmit :).

I realize I did it wrong when I used a 4 AAA NiMH battery holder from Radio Shack and wired it right into the circuit. But I used 1000mAh AAA batteries, I am unsure of their voltage under load, but I did do a file transfer of all the files from my brothers USB SD to my other brothers USB Creative Muvo stick. It worked just fine.

They were 5.28 volts under no load, assuming 1.24 volts per cell under load would give you 4.96 volts, I don't know as it would actually hurt anything at those voltages, and NiMH doesn't drop terribly under high load like Alkalines do.

See the wiki under my Samsung E810 Serial cable mod. (I have since built another e810 serial data cable into my USB adaptor, it is plenty easy to do.) Just figure out which connector is #1 and wire the three necessary wires up, Ground, USB+ and USB- I just did that and put the filtering circuit onto a bit of project board and wired the 5 volt battery pack to the USB socket.
 
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