USB extension cable using cat5e  (Closed) - Page 1
Forum section: electronics / beginners

author: RissViss
author_rank: Regular Contributor
timestamp: May 03, 2017, 04:18:39 pm
content: I need two longer USB extensions, would this worktwo female USB endshttp://www.ebay.ca/itm/182106499544?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITtwo male USB endshttp://www.ebay.ca/itm/172179909567?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AITand one cat 5e 25feet long.https://www.amazon.ca/Monoprice-20-Feet-Ethernet-Network-104991/dp/B003L1705S/ref=sr_1_2?ie=UTF8&qid=1493827442&sr=8-2&keywords=cat5e+cable+20+feetCut the ends on the cat 5e cable and attach the two female ends to one end and the two male ends to the other end. This way I will have two USB ends using one cable. Cat 5e has 8 USB needs 4 each. Or would cat6 be better for this.Attached to this cable will be a mechanical keyboard and Logitech headset with mic.Will doing this cause cross talk, or is there a way to wire it so there is less, like keeping the pairs together.This is to replace a powered 4 port USB hub with a 20 foot extension to PC. Windows keeps dropping the hub then picking it back up, so my keyboard will turn on and off, not good in a first person shooter.Thanks for the help.

author: mariush
author_rank: Super Contributor
timestamp: May 03, 2017, 04:39:11 pm
content: Search amazon for usb along with "active repeater" or "active" and / or 25ft / 50ft / "50 foot"/ "foot" whateverYou'll find plenty of products at less than 20$ that do what you need in a nice way. Then you just plug the hub at the end and do your thing.

author: Ian.M
author_rank: Super Contributor
timestamp: May 03, 2017, 04:47:58 pm
content: The DIY hack job probably wont work. USB uses screened cable with 90 Ohm impedance for the data pair but Cat 5 or 6 UTP cable is unscreened with a 100 ohm impedance. Daisy-chaining good quality passive USB cables is known to cause reliability problems if you significantly exceed the 5m limit in the specification, and using sub-optimal cable with two USB links so high crosstalk is likely to degrade at a significantly shorter distance than the 5m specification.TLDR: your cable is already too long - go buy a commercial USB over CAT5 extender or a long enough USB active repeater cable with at least two device end ports.

author: RissViss
author_rank: Regular Contributor
timestamp: May 03, 2017, 04:55:32 pm
content: Yes I could purchase two of these items, but then I would not learn anything.https://www.amazon.ca/HDE-over-Extension-Cable-Adapter/dp/B004XYEXX4/ref=sr_1_5?ie=UTF8&qid=1493830386&sr=8-5&keywords=usb+rj45+extension+adapter

author: Ian.M
author_rank: Super Contributor
timestamp: May 03, 2017, 05:15:28 pm
content: You wont learn anything anyway, as you don't have the professional knowledge or extremely expensive test equipment to investigate USB signal integrity issues. Yes, there is a remote possibility it may sort of work some of the time, but the odds of success are pretty low - you'd have better odds of winning the Kentucky Derby with a horse that's just been rescued from a knacker's yard.

author: RissViss
author_rank: Regular Contributor
timestamp: May 03, 2017, 05:22:55 pm
content: Thanks for the info.The item I posted about is what I am looking for to fix this problem.

author: Ian.M
author_rank: Super Contributor
timestamp: May 03, 2017, 05:32:02 pm
content: If you are determined to gain practical experience the hard way, at least buy or scavenge some 8P8C 'RJ45' modular jack sockets (not magjacks) so you don't have to cut the Ethernet cable ends, and move the powered hub to the PC end for testing so you don't accidentally FUBAR a motherboard USB port. You'll still waste time and some money but it will be less painful when you have to throw yoiur idea in the trash.

author: mariush
author_rank: Super Contributor
timestamp: May 03, 2017, 05:35:43 pm
content: If you want to learn what you could probably do would be to pick a microcontroller that would behave like a USB host on one end (to plug the keyboard in the microcontroller and make the keyboard think it's connected to computer) . Microcontroller would perhaps run at only USB 1.1 (10mbps) but should be enough for a keyboard, and even for a mouse (the 1000 polling rate may be an issue, bit for 125 hz updates it would probably be fine.raspberry pi3 would probably super cheap and easy and overkillThe microcontroller would get the keyboard/mouse data and arrange it in packets and send it to another microcontroller on the other end through RS-485 or RS-232 .. over 1-2 pairs of ethernet cable, leaving the other pairs to send power to the other end of the cableAt the other end of the cable , one or two microcontroller could be configured as HID (human interface devices), keyboards, mice etc and just pick keyboard data packets or mouse data packets and convert them back to usb messages and give them to computer.Even a low 115 kbps baud rate shouldn't be a problem to send some keys over or some mouse movement.

author: DimitriP
author_rank: Super Contributor
timestamp: May 03, 2017, 05:44:47 pm
content: Quote from: Ian.M on May 03, 2017, 05:15:28 pmAnd even if it works 100% of the time, it's not an indication of anything "learned".Unless "sometimes sttringing wires tohether works when it shouldn't" counts. There...something learned.For six lousy bucks, it's getting more expensive the more it's being dicussed

author: RissViss
author_rank: Regular Contributor
timestamp: May 03, 2017, 05:51:43 pm
content: Thanks for the infoHave a day