Homemade USB Hub?

A

adutch

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Dec 5, 2007
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Does anyone know of a guide on how to make a homemade USB hub powered from the wall? Thanks.
 
Any reason the very cheap ones in the shops arent good enough?
What do you mean by home made, dya want to make it using a home made PCB etc or did you have something else in mind?
 
It's not that the cheap ones aren't good enough. I wanted to make it using some homemade PCB. I just want to make electronics stuff. I just like the feeling of doing something myself. And I know you can't just splice the wires. I don't really care how much it costs as long as it's not outrageous. I was just wondering if anyone had any guides to make your own. Thanks for the replies though.
 
No, I'm in high school. But I did find this http://www.instructables.com/id/Four-port-USB-hub/ which led me to this http://focus.ti.com/docs/prod/folders/print/tusb2046bi.html which has a data sheet at the bottom which shows the whole circuit. Maybe if I learned some more about electronics I might be able to understand what is going on there. Does anyone have any links that might help me understand circuits better? Like explaining all the symbols and everything and stuff like that. Thanks for the help.

edit: Or if anyone knows any good beginner projects that might help me build up to making this? I am about to start a Cmoy amp as soon as my parts get here.
 
A cmoy amp would be a cakewalk compared to building that USB hub. Start out with your cmoy and see how that goes.

Really, for the USB hub, you're not going to understand what is going on if you just buy all the components and try to connect them up.. if you can even get it working. There's so many connections that need to be made, it's really an advanced project. The components used in computer electronics have some fun formula work that goes into calculating out how and if it will work. Being in high school, I doubt you've reached the point in your math classes where it would make sense.

As far as schematic symbols go:
http://www.allaboutcircuits.com/vol_5/chpt_9/index.html

If you like doing that sort of thing, go into Electrical and Computer engineering in college. You'll see/do plenty of it, and you might not like it anymore. :p I'm in my last year or so of my degree, and it seems like it would be right up your alley.
 
USB is quite a bitchy interface it uses differential signaling which can be tricky to decode. If you want to mess with data i'd first start with serial since its almost trivial.

Those chips you listed will do the job, but a complicated plug and play circuit really doesn't do much for you as learning since all the work is done in the chip. The rest is just fluff to make sure the signal doesn't degenerate and the lines have the proper impedance on them.

I wouldn't really consider a USB hub a fulfilling project. I work with embedded hardware (microcontrollers) and they are extremely fun to play with and are limitless in what you can do with them.

Check out my blog where i break down the basics (earlier posts) http://www.mcuplace.com

Also to learn more about simple analog circuits check out: http://www.kpsec.freeuk.com/

Its a great website to teach you all the basics.

Also enjoy your Cmoy pocket amp, it was one of the first projects i did, they are incredibly fun ^.^
 
Wow, thanks a lot for the information Jfkfhhfj and w1retap. I will definitely be looking more into this stuff.
 
Yeah, a CMoy amp or a simple timer 555 circuit would be a good place to start.
 
I'm merely writing a USB stack for an OS right now, and even just from that perspective (data flow, timing) it doesn't seem simple to me to put a USB device together from scratch, let alone a USB hub. Sure, you could put some existing parts together, but the real fun would be in understanding the 'how' and 'why' :)

You could take a look at the USB specification (freely available at USB.org) to get an idea of how an USB hub works. It shows both the hardware and software side.
 
I wouldn't start out with a USB hub. You'll either use an off-the-shelf hub chip from TI or whoever, and won't really learn anything other than how to assemble the evaluation board circuit... or if you try to do it yourself with FPGA and USB transciever chips or something, you'll have a very expensive solution and you'll probably be in over your head right away.

A Cmoy would be an interesting way to start out, as far as hands-on construction, but it's kind of limited in how far you can get with it.

I'd actually suggest getting started with microcontrollers - they're probably the most 'fun' branch of electronics, barring building a tesla coil :) I haven't used a single Arduino (sp?) piece of electronics, but they're talked about endlessly on places like Instructables and the Sparkfun forums.
 
oh; Elledan, check out AVR-USB. It runs a USB stack and physical layer emulated in assembly code on AVR parts.

So far I've used it to build a USB NES controller, right now I'm using it to build a "capslocker" to prank someone at work.
 
gee said:
oh; Elledan, check out AVR-USB. It runs a USB stack and physical layer emulated in assembly code on AVR parts.

So far I've used it to build a USB NES controller, right now I'm using it to build a "capslocker" to prank someone at work.
Click to expand...

I see :) I'll check it out, thanks for the reference :D

Don't go pranking around too much now, okay? ;)
 
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