USB Extender - Page 1
Forum section: electronics / general

author: Juha
author_rank: Contributor
timestamp: October 20, 2021, 03:37:58 pm
content: Hello,So I have been googling the past 2 days trying to find an IC that would extend USB 2.0 up to tens of meters. So far I have not had much luck, the only thing I may have found is CH317 and cant find much info about that either. Im probably using the wrong search terms and even typing that wrong...So the consept is to use usb camera modules for some machine vision stuff but I need to figure out the long distances first. I would prefer to have something that would see the camera as is, so ideally it would be like plugging the module directly to a usb port.There are extenders in the market but I would prefer to at least have the possibility to do something on my own if needed, thus the need for an IC.Has anyone done anything like this before? Anyone have any hints what I am looking for?EDIT:So found another chinese one, Norelsys NS1021. Is this application really so niche that there really isnt a market for IC's. Maybe I will buy an extender and pry it open (just to find one of the above chinese chips inside).Thanks in advance

author: thm_w
author_rank: Super Contributor
timestamp: October 20, 2021, 09:42:37 pm
content: As you said, better off buying an extender, see how it works, cost is under $20. I can't see how integrating an IC makes more sense, at least initially.some of these might be relevant:https://www.epanorama.net/blog/2018/11/19/usb-to-rj45-adapter-teardown/https://fccid.io/PPNM2-100/Internal-Photos/Internal-Photos-156638?__cf_chl_jschl_tk__=pmd_S81JLAL0tTI_XMglXU.rcQoD2Jn60P1fviP32Wcef4s-1634765938-0-gqNtZGzNAmWjcnBszQc9https://fccid.io/UYYEXTWUSB4PShttps://fccid.io/RR-ATN-UCE32100

author: Benta
author_rank: Super Contributor
timestamp: October 20, 2021, 11:16:54 pm
content: The USB 1.1 and 2.0 only support 5 m of cable, 3.0 is more like 3 m.You need switche(s) or even router(s) for every 3/5 m to be compliant.Why don't you convert to something that works well with longer cables? Eg, USB -> Ethernet -> USB. Converters cost a few Euro.

author: thm_w
author_rank: Super Contributor
timestamp: October 21, 2021, 12:09:50 am
content: Quote from: Benta on October 20, 2021, 11:16:54 pmThats presumably what the OP is talking about already,NS1021supports CAT5, coax, etc.

author: amyk
author_rank: Super Contributor
timestamp: October 21, 2021, 02:52:59 am
content: How long do you need, exactly?https://superuser.com/questions/64744/maximum-length-of-a-usb-cable

author: Juha
author_rank: Contributor
timestamp: October 21, 2021, 07:27:19 am
content: Thank you all for the replies.For general testing purposes I can buy an extender, I would like to be able to go up to 30m. But if this would ever develop to something more, I want to have the option to be able to make it myself. Making your own gives a lot more flexibility on the whole camera "enclosure" as you can integrate everything in one piece and just have example an RJ45 plug that needs to be connected.The "make your own" approach is more like having a backup to fall on. Most of the extender/repeaters ICs (example from TI) just extend the range by a couple meters so the USB signal needs to be converted in both ends. LAN is probably the easiest solution, but I was just amazed that there isnt anything out there from the typical manufacturers.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 21, 2021, 12:49:19 pm
content: Quote from: Juha on October 21, 2021, 07:27:19 amLook up "USB/IP". Or since you're dealing with a camera, have the embedded device convert USB to some sort of IP stream.

author: wraper
author_rank: Unknown
timestamp: October 21, 2021, 01:02:59 pm
content: For such distance you need need a Fiber Optic USB cable, a cable with many repeaters in the middle or a USB extender over CAT5E/CAT6.

author: Juha
author_rank: Contributor
timestamp: October 26, 2021, 12:29:02 pm
content: I wanted to avoid this. I have asked the mfgt if they have an English datasheet for the CH317, as a pure HW solution I think this is the easiest (apart from buying an extender). Again, making my own extender is more of a backup plan. I just feel more confident knowing there is the possibility to customize and not having to ”settle” on something thats good enough.

author: Peabody
author_rank: Super Contributor
timestamp: October 26, 2021, 02:44:49 pm
content: Even if you could get it to work, I just wonder how much 30m of cable would cost. For USB2, maybe some kind of wireless setup would work.

author: Juha
author_rank: Contributor
timestamp: October 26, 2021, 04:07:41 pm
content: Quote from: Peabody on October 26, 2021, 02:44:49 pmCost? Cat5/6 cable isnt that expensive. The chip in question should be able to handle 100m through cat5 and up to 6km with fiber. Sorry maybe if I misunderstood something.

author: wraper
author_rank: Unknown
timestamp: October 26, 2021, 06:27:26 pm
content: Evaluation board schematics.

author: antenna
author_rank: Frequent Contributor
timestamp: October 26, 2021, 07:05:06 pm
content: I have a USB cable story, because I too thought there was a hard limit to length...Neighbors down the road have a summer cabin, no internet options (other than satellite) so I decided to share my wifi with them. It is about 1200 feet. I put a router on my outside wall with a better antenna and did the same thing to an ancient USB2.0 wifi adapter for their end. We put the wifi adapter (with antenna) on a pole outside and ran the cable in the window. After being tied to the window got old, they bought 30' of cheap USB3 cable. Surprisingly, it worked through a total of about 39' of cable and the speeds from the adapter (through the woods) averaged 16Mbps. With the same length of cable using the system on the dock with line of sight over the lake, I was getting 45Mbps through that same length of USB cable. The limiting factor for me was the 2.4GHz signal with dense trees and multipath from the lake waves, 10 meters of cable was no issue at all. I would buy a cable of whatever length you need and try it before trying to invent a solution to a problem that may not exist.I bet if I took the laptop to the shed (antenna back here for the season), I could get about 60Mbps through that long USB cable. And if I can do that, I don't think 10 or 20 meters (or more) of cable will be an issue for a USB2 camera. My very first webcam had its cable extended 20 feet with speaker wire and it worked fine

author: Juha
author_rank: Contributor
timestamp: October 26, 2021, 08:05:51 pm
content: Quote from: antenna on October 26, 2021, 07:05:06 pmQuote from: antenna on October 26, 2021, 07:05:06 pmGreat! Thank you kind strangers

author: Bassman59
author_rank: Super Contributor
timestamp: October 26, 2021, 08:30:58 pm
content: Quote from: antenna on October 26, 2021, 07:05:06 pmUSB 2.0 spec for cable length is 5 meters max. The reason for the limit has nothing to do with cable losses. It's because there's a limit based on the time to receive a reply (ACK or NAK) to a packet: if the host doesn't see the ACK in the allotted time it will assume the device is broken. It won't even enumerate.So I take your bet: a 20 m USB cable won't work.

author: thm_w
author_rank: Super Contributor
timestamp: October 26, 2021, 09:06:21 pm
content: I was going to call bullshit, but you can actually buy 25ft long USB 3 cables. Wild.https://www.amazon.ca/Double-Gold-Plated-Connector-Enclosures-Player/dp/B081YTLDF6/Most of the 30ft ones are active with extenders built in though.

author: Bassman59
author_rank: Super Contributor
timestamp: October 26, 2021, 09:24:28 pm
content: Quote from: thm_w on October 26, 2021, 09:06:21 pmWhat good is an A-to-A USB cable?The whole idea of USB precludes that -- the spec is clear on this! There are no USB Devices (not Hosts) with a Type A connector.QuoteThat's right -- they have a hub in the middle. Of course that is an issue if the Device at the far end of the extension requires all 500 mA. It won't enumerate.

author: wraper
author_rank: Unknown
timestamp: October 27, 2021, 06:46:14 am
content: Quote from: Bassman59 on October 26, 2021, 09:24:28 pmI've seen them in practice though. One was a crappy USB microscope.

author: Bassman59
author_rank: Super Contributor
timestamp: October 27, 2021, 05:24:51 pm
content: Quote from: wraper on October 27, 2021, 06:46:14 amKeyword: CRAPPY.