Hub on a chip

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Is there such a solution? A single chip that is designed to manage ethernet communication?

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Are you talking about only the Ethernet layer (i.e. IEEE 802.*)?
Or should it handle more layers of the protocol stack (ie. IP, or even TCP/UDP)?
As you are using the term "hub", are you looking for something with more than one physical interface?

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Yes it would have to be more than the physical layer. I have to do more reading on OSI, but I want to make a hub to transmit DMX over ethernet.

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Get an AVR bd with ethernet.. several are listed in the tools section, add your DMX stuff, and you've created a product. Hub is an 8 way wire-or with no brains... you are describing a bridge... moves from one media to another like ethernet to fiber, etc.

Imagecraft compiler user

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Ya this goes to show how much I know about ethernet. We already have a device that takes the DMX packet and transmits it over ethernet. Now I want to make a Hub, so an 8 way without brains. I'm looking for a chip that would do everything because I know there are the stacks, which I don't know. I found something I think, Davicom Semiconductor.

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Fore sure, there are some old single-chip HUBs, but nowadays their time is over. You can have single chip switches with much more feautures and much better performance as well, e.g.

http://www.broadcom.com/products/Enterprise-Small-Office/Fast-Ethernet-Switching-Products

There are also others, I just dont remember the names...

Peter

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No sense in making an ethernet hub.... those are commodities... you want to make a dmx hub/repeater/router thingy. How about two of those 4 uart avrs coupled together on the spi? 8 channels!

Imagecraft compiler user

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If you want an 8way without brains then just make one... Early hubs were nothing more than a series of RJ45 connectors wired together in a box and unpowered, do it that way.

-Curiosity may have killed the cat
-But that's why they have nine lives

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Are you making an ethernet device or a DMX device or ?? You give us the requirements, we'll help with device selection, etc.

Imagecraft compiler user

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I'm making an ethernet device, the DMX to ethernet is done. I found some solutions at www.broadcom.com. They seem to have Gbps ethernet switch chips. As I did more reading I found that switches are faster than hubs cost being the difference, so I started looking there as well.

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Am I missing something here? You have an ethernet to DMX bridge done and dusted, and now you want a ethernet switch. Why are you not just buying one of these?

http://www.ebuyer.com/UK/product...

You won't get cheaper!

But if you are wanting it all on one PCB, then why are you not adding dmx channels to your project rather than adding a switch and having multiple ethernet to DMX bridges on the same PCB?

You have no need to Gbps ethernet! Routing of high speed signals is a pain in the a**e, so stick with what you need. 10Mpbs would be fine for multiple DMX control.

Tim

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Digi Connect ME is good and quite cheap. It works NETcom-mode without programming. http://www.digi.com/products/emb...

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You can probe with these devices:

www.tibbo.com

... and a new solution from Microchip:
the ENC28J60

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Sceadwian wrote:
If you want an 8way without brains then just make one... Early hubs were nothing more than a series of RJ45 connectors wired together in a box and unpowered, do it that way.

I think that that was when ethernet <=10Mbps, which
used a shared medium (physical cable), which it's not
true anymore these days. You cannot wire anymore
several ethernet cards.

Embedded Dreams
One day, knowledge will replace money.

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Found a Micrel product, KSZ8999I.

The idea is to make a switch that can handle touring, so getting thrown and large temp swings. Basically a switch in a metal box with industrial temp standards. I didn't know that there were solutions on one chip. This is very easy. I thought you had to write software to handle the data flow.

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This wheel is dated late second millennium BCE! ;-)

Seriously though, what are you after? Why don't you just buy an industrial ethernet switch then? By the time you make a PCB capable of PQFP208 packages, buy all of the magnetic, connectors, LEDs and make a case to put it in, and make a power supply, it will be far less reliable, and probably cost more.

Do you need functionality that standard switches don't provide?

What stage is you project at? Can you plug something into your ethernet network and control a single set of lights from a computer yet? How about a drawing? I'm failing to see why you want to make a hub / switch when they are commodity items.

Quote:
Am I missing something here?

Tim

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thanks for the picture of old reliable w0067814...if they sell 8 way hubs/switches for less than 10 bucks why not have a crate of them for touring...you hook one up it works or you toss it and try another one :shock: thats gotta be cheaper than even a bare pcb!

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Nuno, you can still use passive signal routing on 100mbit ethernet, you just have to watch out for signal attenuation, which increases reciprocally with the number of splices. I'm not sure what the practical limitations are.

-Curiosity may have killed the cat
-But that's why they have nine lives

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Sceadwian wrote:
Nuno, you can still use passive signal routing on 100mbit ethernet, you just have to watch out for signal attenuation, which increases reciprocally with the number of splices. (...)

Humm... but to connect 2 ether cards of today, you need a crossed-cable. How do you connect 3 or more?
Or maybe you and me have different definitions of "passive signal routing"?

Embedded Dreams
One day, knowledge will replace money.

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I thought about that for a second Nuno, you're correct you can't do it with just wires, at the least diodes would be required.
I found this site http://www.zen22142.zen.co.uk/Ci...

-Curiosity may have killed the cat
-But that's why they have nine lives

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:lol: hello

check Wiznet.co.kr ...

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Sceadwian wrote:
I thought about that for a second Nuno, you're correct you can't do it with just wires, at the least diodes would be required.
I found this site http://www.zen22142.zen.co.uk/Ci...

Cool hub :)

Embedded Dreams
One day, knowledge will replace money.

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I thought a hub was a schmidt trigger to square up the signal and a 1 bit delay. A switch needs to read the ethernet header and look at the destination addr at least, so it needs a fifo to hold at least the first 6 bytes of the packet before blowing it out to wherever it decides its going. A router stores the whole packet I think, so it has at least a one packet delay.

Imagecraft compiler user

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Just use 10Base5 and vampire taps. :)

Lee

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