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Picture of Four port USB hub
This is a four port USB 1.1 hub built on a tweety bird theme.
 
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Step 1: Getting the components together

Picture of Getting the components together
First, the USB hub controller. Texas Instruments make, among others, one four port USB 1.1 hub in a 32 pin Quad package. They call it the TUSB2046. That is the black square at bottom right, in the picture.

It needs a regulated power supply of 3.3 volts, supplied by a three terminal low dropout regulator. Microchip make one, called the MCP1700T-3302E/TT though the actual chip is a tiny thing. Look carefully, you might just be able to identify it.

The other components were salvaged from various sources. The 6 MHz Crystal came from a Television set, where it was clocking the remote control microcontroller. The capacitors and resistors were unsoldered from various boards from junked equipment.

Step 2: The circuit board

Picture of The circuit board
The circuit board was partly etched, and the rest of the pattern hand carved using a hobby knife. No computer was used in any part of the production of the circuit board.

The only contact the circuit board had with any modern electronics was when it was photographed so that its picture could be displayed in this web site.

A piece of copper clad board was cleaned, and covered with etch resist ( I used a permanent marker pen ) and the integrated circuit clamped over it with alligator clips.

A needle was used to score fine lines where the copper was to be etched away, the ic removed, and the pattern finalised.

Then the board was made the anode in a tank filled with common salt solution with a straightened paper clip anode, and current passed till the pattern was completely etched.

This process, I feel, needs its own instructable and this I might do if wheedled / threatend / cajoled / asked / whatever works.

Step 3: Soldering the components - 1

Picture of Soldering the components - 1
First, the power supply.

The three terminal regulator whose name is longer than the device itself, that microchip wonder, was soldered in together with the two capacitors needed on its input and output.

I took the opportunity to solder some other bits and pieces too.

A piece hacked off an old ISA board became the USB connector. Wires of the proper colour were selected for connecting it - black for the negative, red for positive, and white and green for the USB data lines.

After the voltage regulator was fixed on board, it was time to test it, which was the next step.

Step 4: Testing the work so far - 1

Picture of Testing the work so far - 1
The diagram shows the circuit on the board so far. The voltage regulator was tested by applying five volts to it (from the USB port of my computer) and verifying that the output was indeed at 3.3 volts.

Then a 15 ohm resistor was held to its output terminals, thus imposing a load of about 220 milliamperes, and the voltage was still verified to stay at 3.3 volts - at least, until that resistor had gotten too hot to hold. Microchip says that their chip will supply 250 mA and since Texas Instruments say their chip will draw a maximum of 40 mA I think the two of them will just get along fine.

The rest of those bits and pieces were also tested to make sure that the act of soldering them had not caused them to give up the ghost.

Step 5: Solering the components - 2

Picture of Solering the components - 2
Some more components are soldered in, and then I reach for my multimeter.

On a project of this type, where you are working on a design for the first time, it is essential to take frequent breaks and check the work.

You check the components you just soldered in, then you check the components you had already tested - just in case the action of soldering in the fresh components had not caused the old ones to give up the ghost.

I have added ferrite beads on the incoming supply lines, and the 3.3 V supply line from the regulator to the chip.

Step 6: Soldering the components - 3

Picture of Soldering the components - 3
I solder some more components in.

These are the one resistor and two capacitors around the quartz crystal. Since the crystal is a large thing and I tend to drop the board a lot, it will be put in last of all.

Step 7: Soldering the components - 4

Picture of Soldering the components - 4
I solder in the transient suppressor diodes.

I had a few dual diodes in a Small Outline Transistor package - SOT23 - lying around, and still in place on a junked telecommunication circuit board. This project seemed a great place to give them a second lease of active life.

Step 8: Soldering the components - 6

Picture of Soldering the components - 6
Some more components in. I have cut the islands for the USB downstream ports, eight of them for the two datalines each.

Fine enamelled wires have been soldered to the controller data lines to route over to the series resistors and surge suppressors.

Using fine enamelled wire gives you great packing density over etched lines on board, especially on a single sided layout like this.

Step 9: Soldering the components - 7

Picture of Soldering the components - 7
I tidied up the data lines from the chip to the surge suppressors via resistors.

The texas instruments datasheet says the chip needs 27 ohm resistors in series with all its data lines - all ten of them (eight downstream, two upstream). I could find only 22 ohm resistors in the various junked boards I could collect, so they would have to do.

The pads of the chip were tinned in preparation of soldering it in position.

Step 10: Soldering the components - 8

Picture of Soldering the components - 8
There - I have soldered the crystal in, and now only the chip is left.

So now I know that every component has been connected up correctly, and is functionally all right, because I have been testing them after each operation and rectifying any defects I found.

Now is the time for a quick check. Connect it to the computer and see what it has to say.

Since the USB hub controller is not in yet, it will have to report a fault. I want to see that fault message.

Step 11: The error message in case it doesn't work

Picture of The error message in case it doesn't work
This was the reaction of windows xp to the chipless controller. One data line is pulled up to +3.3 V through a 1.5K resistor and this tells the computer there is a fresh device on the bus.

However, its queries elicit no response so it decides that a faulty device has been plugged in.

Great. Now we know what to expect if we goof up.

Step 12: It works!

Picture of It works!
After the chip was soldered in and the device plugged in, the "new hardware found message" was replaced by the "device is installed and ready to use" message balloon.

Step 13: The final board so far

Picture of The final board so far
This the work done so far. The upstream port connection is done, but the four downstream ports have to be connected.

And a wav player that says "I taw a puddy tat" is in the works, and it will be built into a pedestal below the tweety pencil holder in the first picture.

Step 14: Generic Hub

Picture of Generic Hub
Windows XP has recognized my handiwork as a "Generic USB Hub". I just obtained the chip from Texas Instruments and followed the circuit on their datasheet.

So the credit should really be awarded to them.
chilll20096 years ago
Can you buy the stuff at radio shack???
AdamM4 chilll20099 months ago

no you cant

baubstae2 years ago
"The only contact the circuit board had with any modern electronics was when it was photographed"

This seems a bit silly given the complex IC about to be soldered to it. I don't see the point of this comment.
HomerS4 years ago
does there need to be a "system power on reset" ?? and what reset thing do i use. i found one that needs a sense thing using resistor, not sure what resistors to use.
rajendra1235 years ago
ok
9H1LO6 years ago
can we have a proper schematic for this? i will gladly make a proper pcb layout
neelandan (author)  9H1LO6 years ago
The schematic can be taken from the device data sheet available at TI web site. They recommend the use of more TI components in order to make it into a complete fully featured USB hub.
9H1LO neelandan6 years ago
there is lots of stuff on that datasheet i will try and remove what makes sense to me i already have the chip and i have MC33269DT33G as 3.3v regulator
emmotic6 years ago
I'm sorry im too stupid but, can you list the materials needed for this project? Thanks :)
Dael8 years ago
So I recently switched from my PC, which has sadly died, to my laptop, and I am finding myself short of USB ports. I was thinking, "Hmmm, I need a USB hub, and it would be awesome to build one". So I come across your Instructable and think, what luck! I was just wondering though, would you be able to post a schematic?
binnie Dael8 years ago
its cheaper to buy one than make. plus eaiser!
Dael Dael8 years ago
Nevermind, found one. =)

I was being lazy and completely forgot to check the data sheet app notes.

Anyway, great instructable!
mrmath8 years ago
You lost me. I couldn't follow it. Not because it wasn't a good instructable. I hae to say, I think it is a good one. It's because it had too many big words my little brain couldn't handle! I'm a wannabe. I wannabe able to do this kind of stuff.
binnie mrmath8 years ago
go back to geek school this is easy stuff the hardest bit about it is the smd
mrmath binnie8 years ago
There are many different types of geek. There's software geek. There's hardware geek. There's electronics geek. Science geek. Star Trek geek.... Just because I don't/can't follow what he's talking about with electronics doesn't make me less of a geek. It just means I took a different curriculum when I went to geek school.
binnie mrmath8 years ago
lol yea true true i fall under all those catagorys xcept the startrak one lol you sound a bit like my mum ( has a mental block on technology ) i havnt been to geek school yet, and im waiting till i leave school ( nother 4 years awww) But if your brain cant handle silly big words that make no sence to nobody why do you bother reading it. yes to learn good reason
neelandan (author)  mrmath8 years ago
There are more steps in between, because I popped the board onto my scanner every time my wife called me in for dinner, my daughter asked to sharpen my pencil, and the dog wanted to go out. When I am writing the text I shall take care to explain any large words. Wannabes can become tech experts if they want, and work, hard enough. Allow me to help.
Shriike8 years ago
How much does this project cost? I was looking for a usb hub and this looks like it might be fun
neelandan (author)  Shriike8 years ago
If you are looking for a USB hub - buy one. If, on the other hand, you wish to delve into the mysteries of self and bus powered hubs and what happens when a faulty device gets plugged into one and when your kid pushes a metal object into the USB receptacle - jump right in, and be prepared for a long journey before a completed hub gets engineered to your satisfaction.
cold_fusion8 years ago
Very nice, I have used FeCl before for etching but tend to use vero for projects because its nasty stuff. I would definitely like to see an instructable on your salt etching method. Keep up the nice project!
Does the etching process have advantages over the usual Feric Chloride method? If so I would be interested in seeing the instructable Pete
neelandan (author)  PeterTheUnGreat8 years ago
The salt doesn't etch until the current is switched on, while the FeCl is corrosive all by itself. For prototyping, where you can baby it along, I think the electro-etching process is better because of the less corrosive naure of the common salt. It is corrosive, however, and all traces must be removed from the finished board.
I messed around with this tonight, and all I got was rusty water! Does the copper board connect to positive (anode) or negative (cathode)? And do you think the salt concentration should matter much beyond conducting electricity? I'll play around some tomorrow, but I've got cooking to do too. -- Elliot.
neelandan (author)  The Real Elliot8 years ago
The PCB should be positive. If you got rusty water, then you made the iron +ve.
rotor neelandan8 years ago
I'd very much be interested in an instructable on this. I've stayed away from pcbs because I have a tiny house with a small child, and I'm not real keen on keeping strong acids anywhere the kid could get to it.
ajelliot8 years ago
Gotta know more about how you etched that board.
OK, I'll bite.

Table-salt-solution electro-unplating? That's freaking genius. How long does it take? Voltages? Etc?

I think you're right -- your method does need its own instructable. One reason I shy away from FeCl etching is the horrible chemicals, and what they do both to my sink and the environment at large. If you've got a better way, I'm dying to hear it.

Consider yourself cajoled.
neelandan (author)  The Real Elliot8 years ago
I use 12 volts from a 500 mA AC adapter (commonly called a wall wart). Only a small amount of copper needs to be etched away so the method is reasonably fast, around 5 - 10 minutes. I prefer using this because the salt solution, before and after the event, is only as corrosive as the original salt - ie, it is not a great thing to spill onto your table top or into your keyboard, but if you get it on your skin or clothes or the floor that's no great disaster. I've gotten rid of my store of FeCl and now get my PCB's done professionaly - those of my prototypes that work, and needs to be produced in 2 + quantity. I'm going to document it the next time I try another such board, but right now the tweety bird is taking up most of the little free time I get. Thanks for the encouragement.
Brilliant! Add me to the cajoling list too.
neelandan (author)  The Real Elliot8 years ago
I use 12 volts from a 500 mA AC adapter (commonly called a wall wart). Only a small amount of copper needs to be etched away so the method is reasonably fast, around 5 - 10 minutes. I prefer using this because the salt solution, before and after the event, is only as corrosive as the original salt - ie, it is not a great thing to spill onto your table top or into your keyboard, but if you get it on your skin or clothes or the floor that's no great disaster. I've gotten rid of my store of FeCl and now get my PCB's done professionaly - those of my prototypes that work, and needs to be produced in 2 + quantity. I'm going to document it the next time I try another such board, but right now the tweety bird is taking up most of the little free time I get. Thanks for the encouragement.
Vermin8 years ago
That's the funkiest prototyping method! I second The Real Elliot's request.
I too liked the 'knocked up in my shed' aesthetic of the project. Nice. Pete
ellinger8 years ago
Nice combination of old-tech and new-tech. Great re-use of parts. I fully expected to see a commercial hub disassembled and reassembled into the tweety bird. I am pleasantly suprised.