Usb Dongles for USB Over CAT5 Connection





Introduction: Usb Dongles for USB Over CAT5 Connection

You can run pretty much anything on Cat5, VGA, Usb, Sound Signals, S-Video and so on.

I'm planning in using my web cam as a security cam at my front door and I was thinking in using a pc downstairs to see my web cam over the net, but I have keep both pcs running at the same time and the need of extra software as well, so i decided to use a Cat5 to run a Usb connection over at least 25', I've been searching a little over the web and I found a couple of ideas to connect Usb peripherals over Cat5 successfully and I went over the subject, but I realize that i didn't want to cut the cat5 and solder the usb connections to the cable, so I decide to build a couple of Usb dongles (female and male) to cat5 and the cool thing is that they can be used on existing Ethernet network wall connections as well. I know that I might be pushing the limits but it's worth the try.

I wouldn't use this devices for Data tho, I understand the there are plenty of connectors out there that have baluns (which I don't quite know how they work), to send and receive Data signal, so I wouldn't risk the try but for peripherals such as web cams, mouse or keyboard, and sound signals would do just fine (even S-video).
I would highly recommend using a powered Usb hub for the distance mentioned above, in regards of some of the limits for this type of configurations:
Usb limits are up to 15' (4.5 meters)
S-Video up to 50' (15' meters)

I got very useful information from Tony's Cafe blog, on distances limits and some other valuable info, you may want to take a look at his site:

Step 1: Materials and Instructions

The Dongles or connectors are very easy to build, I gather all the material from salvaged hardware

2 Ethernet Hubs (8pin RJ45 - salvaged from network cards)
1 Usb Male Plug Type A (any standard Usb cable)
1 Usb Female Plug Type A (from a Pc)
Solder Gun, wire and electric tape.
and of course a CAT5 Ethernet Cable

The hardest part was desoldering the Hubs from the salvaged PCB board, after that it was just a matter of selecting which cables of the CAT5 use to solder the Usb plugs and the RJ45 Hubs.

I select the pins in the following order:

RJ45 hub = USB plug
pin No. 2 = Green Cable
pin No. 4 = White Cable
pin No. 6 = Black Cable-Ground
pin No. 8 = Red Cable

I test the configuration at the other end and test the web cam (my work very well) later I isolate each soldered connection with electric tape (with yellow tape) and cover the hole thing (black tape), and voila!. 25' of video cable (plus the hubs) and working.
Easy and extremely cheap.



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    70 Discussions


    8 months ago

    Is there a downloadable software(4 channels or more) also that has the same function as CCTV using PC camera. I would like to set-up monitors in my house.

    is it possible to get netgear 85 router to receive wifi signal from an outdoor antenna with usb to ethernet splice? Reason being me and neighbor share off of his internet but my usb adapter doesnt pick up signal from his router anymore but does with my outdoor antenna. also have amped wireless repeater that i boosted signal with now it is not apparently receiving signal.

    Tis a shame that usb traffic cannot be routed! Think of the possibilities just plugging in a usb to a network port in a school or office and receiving a file with just a button press!

    Thought of using the other way around? Male jack on usb to female/female extension? (less common I know, but available!)

    It seem that peoples here know nothing about electronics and USB specification...  So I will let you know why USB can't work over 5 meters.

    This is all about timing. at 5 meters, the delay propagation in the cable is maximum 26 nS(Nano Seconds).  This is the time the USB transceiver will wait after a packet transmission for an ACKnowledge answer.

    So if your cable is longer, the ACK will be received too late, and the USB transceiver will be already in the timeout processus.  It's for that reason that if you want longer cable, you need Active USB repeaters.  These Active cables Are real relays that send ACK signals and re-transmit the data over another 5 Meters cable.

    There is nothing about voltage drop or crosstalk here.

    2 replies

    You're right. A person would be lucky to get USB 1.0 speeds out of a hack like this, if it works at all.

    It can not be that critial, since its working!
    Once I ran RS232 over a 300 meters telephone cable! (max=16 m?)
    It was working constantly for more than one year.

    Sometimes we may test the "impossible" and it works.

    Is there any possibility of this working on a router, am looking forward to connecting a 3g usb dongle to the rj45 wan port of my router running a linux distro so i can establish a dialup connection. Pease any help will be appreciated

    Three things on running USB over Cat-5 wiring:
    1. On the RJ-45 8-pin jack, you want to avoid pins 1,2,3,6 because if it accidentally gets plugged into a switch or PC Ethernet jack, the 5-volts could fry something.

    2. You want the power (+5v,ground) on the same color (blue,blue-stripe) so it doesn't make an electronic field that can ruin the valuable data lines. the phone company runs 24V to our homes on one twisted pair of wires and it works fine.

    3. Twisting the two data lines on one color (brown,brown-stripe) will keep data integrity over a longer run of lines. Ethernet lines do that and it works just fine.

    I suggest the following from the USB to the Cat-5 jack:
    1. usb pin 1 (+5v,red) goes to RJ-45 pin 5 (blue-stripe)
    2. usb pin 2 (d-,white) goes to RJ-45 pin 8 (brown)
    3. usb pin 3 (d+,green) goes to RJ-45 pin 7 (brown-stripe)
    4. usb pin 4 (ground,black) goes to RJ-45 pin 4 (blue)

    Using this configuration, you could simultaneously run Ethernet to a hub AND your USB extension with splitters and all.

    2 replies

    I actually used this configuration for a USB web cam. Just a note, some USB's have an wire insulation that has nothing to do with making the connection just a tip for noobz like myself. I also had to cut down my Cat5 cable to about 3 meters because I was getting an error of non-recognized hardware. Thanks awesome Instructables and awesome tips!

    Why does it tell me that my USB device is unrecognized when i pplug it into the cable?

    try this one out hope thats help

    just curious, is this whole instructable about extending your usb cable using an ehternet cable (cat 5)? Thats pretty neat, but what i was curios about was if it was to be possible to instead of making an extension, to convert or merge a usb cable and ethernet cable to work together. Its kinda far stretched, but the only hard part in this is figuring out which wires to connect or pair. So on the usb side, which has four wires (red,green,white,black) to the ethernet cable by connecting the wires together in the right way.... Possible or impossible?

    6 replies

    Actually it is possible to run other things over a cat5 cable. Search up "POE pinout" and you will find that the brown and blue pairs are not used by a standard networking devices. You SHOULD be able to run the 4 usb wires over the 4 spare wires... but i will warn you, there could be LOTS of interference. If you have any networking equipment that has POE you will probably destroy your networking equipment, usb device and your computer :) but if use disconnect those connections to your devices you should have TOO many issues... have fun!

    So it is possible?? :D but I'll destroy my equipment?? Lol.... That's a hard decision...

    no, as long as you disconnect the blue and brown pairs from the cable and not splice them you should be fine. Just put that as a warning......

    Ok so if I'm using a already made ehternet cable, and cut one end of the cable off to expose the wires, it'll work? By doing what you said, of course

    just use a knife and strip off the outer jacket. Then cut only the blue and brown pairs out. do this on either end and just be careful not to cut or untwist the green and orange pairs. oh and by the way, keep the power and data connections on different pairs to minimize interference. Doing it this way will help keep your networking equipment intact :D

    Thanks for these fast replys, I will defiantly try this when I get time