Where to start in designing a USB hub? - Page 1
Forum section: electronics / beginners

author: Seytonic
author_rank: Newbie
timestamp: November 28, 2016, 05:33:25 pm
content: Hi, I've made a few embedded projects recently built around arduino, though one of my projects requires a built in 2 port USB hub. I've searched around and can only really find schematics for controller chips that I could potentially usehttp://www.ti.com/lsds/ti/interface/usb-hub-controller-products.page?paramCriteria=noThough I'd like to understand what I'm doing rather than just following a schematic, if anyone could point me in the general direction of resources that could help me understand this topic a bit better that would be great.

author: MosherIV
author_rank: Super Contributor
timestamp: November 28, 2016, 06:06:26 pm
content: QuoteThe reason you do not find any info on how to do it is because no body does it.You just get a USB Hub device chip and implement the design around it.QuoteThe classic book 'USB Complete' has the information that you need.You could try a whole number of web sites :http://www.usbmadesimple.co.uk/But I have not checked them out.in quick simple terms (from memory), a USB Hub must :scan all the ports for insert/removal - tell the host when this happensWhen insert detected, must provide power and do a handshake with the device to get type and power, then power device down again and report to Host. (I may be mistaken, it might be the host that requests the power up and handshake)The host must then tell the hub what to do.Why go to the bother when you can just get devices that do it all

author: Seytonic
author_rank: Newbie
timestamp: November 28, 2016, 06:16:33 pm
content: Quote from: MosherIV on November 28, 2016, 06:06:26 pmThanks for your response, though I probably wasn't clear enough, I'm not looking to implement it from the ground up I'm going to base it around a USB controller, its just I can't find any information other than the datasheets on how to go about it. Datasheets are great, but I've never really done anything like this before so if anyone has and has documented the process that's what I'm looking for.

author: yngndrw
author_rank: Regular Contributor
timestamp: November 28, 2016, 06:19:11 pm
content: I don't know if this is any use to you:https://www.tindie.com/products/mux/nanohub-tiny-usb-hub-for-hacking-projects/The seller also has a 4-port version:https://www.tindie.com/products/mux/4-port-nanohub-tiny-usb-hub-for-hacking-projects/

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 28, 2016, 06:29:11 pm
content: The controller's datasheet will tell you what it needs to work correctly. What kind of additional information are you looking for?

author: Seytonic
author_rank: Newbie
timestamp: November 28, 2016, 06:30:30 pm
content: Quote from: yngndrw on November 28, 2016, 06:19:11 pmNow this I like, after some searching I found the schematicsPerfect, thanks. The schematics for anyone who finds this thread in the future:http://muxtronics.nl/nanohub.html

author: senso
author_rank: Frequent Contributor
timestamp: November 28, 2016, 06:40:59 pm
content: The TI chip and many others also have schematics, they even call it typical usage..

author: amyk
author_rank: Super Contributor
timestamp: November 29, 2016, 03:34:29 am
content: It depends what you mean exactly by "designing a USB hub". As others have mentioned, the ICs which are available require nothing more than power and a few passives. If you actually want to implement a hub, then you're going to have to read the USB spec.