Ethernet shield diagram help...

I have an attic full of old PC components so I'm pretty confident I will have most, if not all of the required bits'n'bobs to create my own breadboard Ethernet shield. However, I cant find a schematic to make one. Can anyone help with this?

Thanks

There's a schematic on http://arduino.cc/en/Main/ArduinoEthernetShield but without knowing exactly what parts you have, I don't know if it will help you.

I very much doubt you'll find the components you need for an ethernet shield in a PC.

PC network cards are considerably more complex than an Arduino one. For a start, they are interfaced with a bus like the PCI bus or similar. The Arduino doesn't have such facilities. Instead, it's usually the SPI bus that is used for controlling the Ethernet card.

So, you will require an ethernet chip that talks SPI - something that you just don't get in the PC world (it's too slow).

There's two basic chips that are used - the W5100 from Wiznet, which is on the "official" ethernet shield. This is an all-in-one chip that provides both the ethernet interface and the IP stack. It makes programming it from the Arduino's point of view very easy.

Then there is the ENC28J60 from Microchip. This is just an Ethernet interface chip that is controlled by SPI, and it requires that the Arduino generate all the packets to send, so you need an IP stack in software. There are a number of schematics online for this chip, and libraries to go with them, but due to the limited resources of the Arduino it's hard to create a good, full featured library to support this chip.

dxw00d: There's a schematic on http://arduino.cc/en/Main/ArduinoEthernetShield but without knowing exactly what parts you have, I don't know if it will help you.

majenko: I very much doubt you'll find the components you need for an ethernet shield in a PC.

PC network cards are considerably more complex than an Arduino one. For a start, they are interfaced with a bus like the PCI bus or similar. The Arduino doesn't have such facilities. Instead, it's usually the SPI bus that is used for controlling the Ethernet card.

So, you will require an ethernet chip that talks SPI - something that you just don't get in the PC world (it's too slow).

There's two basic chips that are used - the W5100 from Wiznet, which is on the "official" ethernet shield. This is an all-in-one chip that provides both the ethernet interface and the IP stack. It makes programming it from the Arduino's point of view very easy.

Then there is the ENC28J60 from Microchip. This is just an Ethernet interface chip that is controlled by SPI, and it requires that the Arduino generate all the packets to send, so you need an IP stack in software. There are a number of schematics online for this chip, and libraries to go with them, but due to the limited resources of the Arduino it's hard to create a good, full featured library to support this chip.

Thanks guys, some of the stuff I have in the attic is pretty damn old. Some 1/10 NICs up there I think. I'll take a look to see if there is a wiznet chip.. I'll let you know.

Actually thinking about it I think I'm going to take your advice Majenko and just buy one. Ebay - £7.43 http://www.ebay.co.uk/itm/Ethernet-Shield-W5100-For-Arduino-328-UNO-Mega-2560-EKitsZone-UNO-/221088934086?pt=UK_Sound_Vision_Other&hash=item3379ed68c6

At that price you can't say no, really, can you?

=M=