I have never written any Arduino code against an enet or wifi shield... I am looking to implement a minimal web server to do a little testing with my existing application. That means, I can't sit around waiting for data to come in. Does the wifi shield have the ability to trigger an interrupt when some data arrives, or must it be polled? Does it have any kind of buffer like a UART or does it need to be serviced immediately upon data coming in?
I would get one and try it, but if its a no brainer that it needs the full attention of the CPU then I'll probably go the route of designing a special purpose wifi shield with its own uC on it...
Thanks...
Jim
PS - Along these lines, does anyone know of an existing wifi shield with its own uC on it?
Does the wifi shield have the ability to trigger an interrupt when some data arrives, or must it be polled?
It must be polled. The actual connection triggers interrupts, but those are not available for your code to extend.
Does it have any kind of buffer like a UART
Depends on the specific shield and library, but, in general, yes.
but if its a no brainer that it needs the full attention of the CPU then I'll probably go the route of designing a special purpose wifi shield with its own uC on it.
What else is the Arduino doing? If the Arduino is already busy a significant portion of the time, will it really have time to act as a web server, too?
Along these lines, does anyone know of an existing wifi shield with its own uC on it?
Take a look at the WiFi Bee. It's a Microchip WiFi module (as is on the WiShield) together with a ATmega328, something like a complete Arduino in the Bee format.
PaulS:
What else is the Arduino doing? If the Arduino is already busy a significant portion of the time, will it really have time to act as a web server, too?
It does not, which is why I'm looking for a wifi shield with a uC on it. The Rugged Circuits Yellow Jacket is pretty close. The processor is a little low end though. But it, or an Uno with a dump wifi shield, will get me started on prototyping.
Along these lines, does anyone know of an existing wifi shield with its own uC on it?
Take a look at the WiFi Bee. It's a Microchip WiFi module (as is on the WiShield) together with a ATmega328, something like a complete Arduino in the Bee format.