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DIY USB Extension Cables Using Cat5/6?
TheDarkRogue asks: "Ok, I have a small USB device that I need to position a distance from my computer, more then the cable, at least 30 feet. The thing is that I don't think it can go that far very well. I looked around for a solution and found a few products I could get for a price way out of my price range, so now I'm looking at this as a doit-myselfer. How can I extend the distance using Cat5/6? Does anyone know of any schematics for something or is that in its self more then is needed?" Extending a USB cable to this length (or more) can't be this easy, can it? What's the maximum length of USB cabling one can get in a single stretch?
http://www.google.com/search?q=usb+maximum+cable+l ength+specification
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http://www.google.com/search?q=usb+extension+cabl
Slashdot is jumping the shark. I'm just driving the boat.
Can long cables really be this easy? Maybe...
I dunno, I needed to network two machines QUITE a distance apart, so I made a crossover UTP network cable out of an existing UTP patch cord and several hundred feet of speaker wire, as two pairs (send pair and receive pair).
Works perfectly. Blazing fast, too. I would say that I just got lucky but I do these sorts of things all the time....
You may very well be successful with the Cat5/6 option. My excessively-long ethernet cable made out of speaker wire has been functioning flawlessly for months (in fact, I built another to network hubs at vertically and horizontally opposite corners of my household, and it has also worked like a charm).
--TheOrangeSquid Is it any wonder things seem so awry? We swim in a sea of confusion and don't have to think to survive
Ok, I have a small USB device that I need to position a distance from my computer, more then the cable, at least 30 feet.
Hot chick moved in next door, huh?
And you've found the perfect perch for your webcam, right outside her bathroom window?
And you don't want to get a wireless X-10 camera, for fear of being spammed and popped-under every day for the rest of your life?
Opinions on the Twiddler2 hand-held keyboard?
You can't just go hacking into a USB cable and make it longer. Probably the #1 reason is that USB uses a differential signal. That means that however you extend the cable you have to do it exactly the same on both D+ and D-. If you don't, part of your diff signal gets skewed and becomes corrupted at the receiver. Secondly you have to maintain an imepedance match. Anytime you introduce an impedance mismatch you generate reflections. The wire used in a USB cable has a certain about of reactiance (X). The X of a twisted wire pair is completely different.
In order to do what you want, you really need to build a fairly preceision amplifier/receiver setup. The difficulty is the fact that you are dealing with differential signals. Each "side" of the diff signal must be treated the same way. It is almost impossible for you to make the exact same size solder joints, exact same size wires, and have the exact same impedances throughout. Its especially important on long runs because of the highly immentant signal attenuation.