Beginner's question about Ethernet Shield + SD

Projects General Guidance
1

Hi all,
Is it possible to fully load a web page from the Ethernet Shield SD card?

Like for example, I design a HTML page in my PC and then save it to the SD card for the Ethernet Shield, will the page be fully operational? We are talking about a simple page of course, with some links to other pages and a few images.

If the answer is yes, I then have another doubt, will I still be able to use certain arduino functions with the html page I loaded from the sd card? Like turning on or off a LED, for example.

2

Is it possible to fully load a web page from the Ethernet Shield SD card?

Yes...

We are talking about a simple page of course, with some links to other pages and a few images.

The images should be links, too. Store them somewhere else, and link to them on your page, rather than serving the images.

will I still be able to use certain arduino functions with the html page I loaded from the sd card?

Well, the page is served up (sent) to a browser running on another computer, so the Arduino functions will not be available there.

If the page contains a form, and the form has a submit button, the action behind that button defines what happens. Typically, the submit action causes a modified GET request to be generated, and sent to the server that responded to the initial GET request.

The modified GET request has data from the form added as arguments. If the original request was "GET /mypage.html", and that page contained a form with a field named Name and a submit button, and you typed Rainier9 in that field, the modified GET request would be "GET /mypage.html?Name=Rainier9".

It is up to you to write the code to recognize the difference, and respond accordingly.

You can develop the page on the PC, and press the submit button. The title bar will change as you pick buttons, enter text, select check boxes, etc.

Define the form you want to see, and observe what the various requests look like as the form widgets are manipulated. This will tell you what the Arduino needs to deal with.

Parsing the GET request is not all that difficult. Reacting to what you parse is up to you.

3

Here's another question along the same line.. is it possible to load a pre-written page and send it over the ethernet, similar in design to the app example for the Spinnerette server made by Parallax? I.E. a simple page of buttons (or HTML links) from the SD card, sent to the ethernet, viewed on a remote device (in this case, the wiznet shield w/SD card, connected to a WiFi router, on a mobile robot, monitored by a laptop receiving the WiFi link, to control the robot, and one of the link buttons, having the task of resend the page (not needing to constantly reload the page from the browser command line.))

4

is it possible to load a pre-written page and send it over the ethernet, similar in design to the app example for the Spinnerette server made by Parallax?

I'm not familiar with the Spinnerette server, but, yes the Arduino can act as a web server.

I.E. a simple page of buttons (or HTML links) from the SD card

If the page is simple, there is no need to store it on an SD card. It's only when the page is too large to fit in the Arduino's memory and/or program memory that storing it on an external storage medium is needed. If that's the case, having the Arduino serve it is probably not appropriate.

having the task of resend the page (not needing to constantly reload the page from the browser command line.)

No, this last bit is not possible. Client/server connections are not persistent. Trying to make them so is an exercise in frustration.

However, a web page that is served up can include Meta tags that tell the client to fetch the page again automatically after any desired period of time.