I thought it would be kind of cool to be able to control an Arduino remotely so I hacked up a bunch of code that allows me to do this. The website can control multiple Arduino's at one time and recognizes them by their unique IDs that they send.
Basically, what you need is:
A computer running Linux
How it works is like this:
1. Arduino sends data to the Serial port that is polled by computer_interface.pl and written to a file that is plotted using gnuplot to display on the webpage
3. Webpage uses web_interface.cgi to write data to a file that is read by computer_interface.pl and sent to Arudino
2. Arduino is polling Serial port to receive data and uses the data to modify variables that can change how the Arduino operates.
What this code was written for was having an Arduino controller multiple pieces of equipment in a Scientific lab but it can be ported to use for many other things.
Here is the Arduino Code: http://pastebin.com/f8eBJc7R
Here is the computer_interface.pl: http://pastebin.com/yGNMCH54
Here is the webinterface.cgi: http://pastebin.com/qpUZ5n9A
Here is the gnoplot formatting file should be in the same directory as computer_interface.pl: http://pastebin.com/1BWNaAc4
HTML file: http://pastebin.com/e2Fpkrfi
HTML CSS: http://pastebin.com/1YUnWS0Q
1. Install gnuplot: apt-get install gnuplot or yum install gnuplot
2. Put the HTML files in /var/www/html
3. Setup Perl execution on your webserver (http://stackoverflow.com/questions/560749/how-do-i-configure-apache2-to-run-perl-cgi-scripts)
4. Make sure you Arduino has code loaded and is plugged in.
5. Run computer_interface.pl in background and make sure the gnuplot file is in the same directory
The webpage refreshes every 30 seconds you can change this in example.html.