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Topic: Arduino Ethernet Shield (Read 11 times) previous topic - next topic

nuelectronics

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En...  It is a good idea - can be implemented with Full TCP/IP protocol rather than the Single data packet at the moment.   But are we going to reinvent the WIZNET module?  

What? Your shield only does single packets? (UDP only?)
Hmm that limits its usefulness.

Maybe switch over to Wiznet with a onboard AVR controller?
The Wiznet chews about 8kb as well to interface with it.
But it can handle TCP/IP in hardware which makes it substantially simpler.


No... We have webserver implementation, and HTTP is based on TCP.  It is the a simplified TCP/IP implementation that uses the "single data packet",  which  sends the FIN immediately together with the data,  rather than uses standard multiple packets TCP/IP protocol.  

This makes the state handling for the closing of the connection a lot simple, and leave more space (flash & RAM) for user application.   "Single data packet" means that your webpage(s) needs to be in one packet (limited by 1K RAM space), which should be OK for many applications that Arduino can handle.

follower

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Also have you considered putting a AVR on the shield so the code required to interface with it is reduced?

But are we going to reinvent the WIZNET module?  

It does sounds a little that way. :-)

I've actually previously contemplated making a Netduino shield with an AVR on it that would provide a Lantronix-compatible interface, but it's still on the "to do" pile.

--Phil.

Cheater

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This makes the state handling for the closing of the connection a lot simple, and leave more space (flash & RAM) for user application.   "Single data packet" means that your webpage(s) needs to be in one packet (limited by 1K RAM space), which should be OK for many applications that Arduino can handle.

Well that technique makes it completely useless for most purposes. :(
HTTP is basically the only protocol which does that.

Sticking a AVR on the shield gives you significantly more power.

nkcelectronics

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Also have you considered putting a AVR on the shield so the code required to interface with it is reduced?
Put all the low level code on the on board processor and expose a simple API over I2C or something.

En...  It is a good idea - can be implemented with Full TCP/IP protocol rather than the Single data packet at the moment.   But are we going to reinvent the WIZNET module?  

Not a chance... wiznet can handle 25Mbps, put in a module for $20.  This is far less powerful and more expensive.  I should say what is being reinvented is the stone wheel

aballen

Where can you get a wiznet module for $20?  Everywhere I look they are closer to $40, and thats just the wiznet module... then you need a shield, are you telling me you can get this put together and retail the whole thing for less then $24, cause if so I want one.  This was only $24.  For the price I think its pretty nice.

Ladyada has a really nice shield out, but I it's another $40 for the wiznet module... thats pretty much everywhere.

I think this is pretty useful.  1K is a pretty big message to send from a device with a limited amount of memory.  Mine will serve up tiny xml messages that are consumed and displayed elsewhere via xsl transform.

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