Aim:

Switch relays from the ethernet or the internet, using your mobile, tablet or computer with a nice graphical user interface.

Update V4.06
Please read the below steps to Step 2 if you are viewing this article for the first time.
Please go to step 3 for the latest revision which is V4.06
A user modified version with logon option is placed in step 5 for easy download.

Material:

    * Arduino MEGA 2560
    * Arduino Ethernet Shield
    * Relay board
    * RJ45 cable


Tools:

    * Arduino Software version 1.0.1 (downloadable from Arduino Website )
    * A / B USB cable


Infrastructure:

    * Internet access with fixed IP for Arduino
    * Access to your router to share the port for internet access
    * Testing devices - your pc, mobile etc


Disclaimer:

    * This project was tested with iPhone 3GS, iPad 2 and MacBook Pro running Safari and PC running Safari, Firefox, Opera and IE.
    * This project was created on October 2012 with the mentioned material.
    * Binary sketch size: 22,322 bytes (of a 258,048 byte maximum).
    * This sketch does not offer any sort of authentification, therefore if required to be used from outside the network or from the internet, I suggest to configure your network to connect trough VPN. Nowadays many routers and smartphones support VPN.

Description:

    * With this project, I had not included any images, or links to images from the internet. It only make use of CSS3 and HTML5.
    * The simulated LEDs are created from CSS3 code.
    * Some browsers does not make full use of CSS3 and HTML5. Thus I suggest using Safari.

//Ethernet Switch
//
//Intro:
//This will swich on and off outputs trough your mobile device.
//No images or links to images. CSS3 and HTML5 use.
//Though it work with other web browser, we suggest Safari for best experiance.
//
//Version: Web Server Ethernet Switching Version 3.05
//Author:  Claudio Vella - Malta
//Initial code from: http://bildr.org/2011/06/arduino-ethernet-pin-control/
//Made lot of comments for beginners.

//ARDUINO 1.0+ ONLY


#include <Ethernet.h>
#include <SPI.h>


////////////////////////////////////////////////////////////////////////
//CONFIGURE
////////////////////////////////////////////////////////////////////////

  //IP manual settings
  byte ip[] = { 192, 168, 1, 177 };   //Manual setup only
  byte gateway[] = { 192, 168, 1, 254 }; //Manual setup only
  byte subnet[] = { 255, 255, 255, 0 }; //Manual setup only

  // if need to change the MAC address (Very Rare)
  byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

  //Ethernet Port
  EthernetServer server = EthernetServer(80); //default html port 80

  //The number of outputs going to be switched.
  int outputQuantity = 8;  //when added to outputLowest result should not exceed 10

  //The lowest output pin we are starting from
  int outputLowest = 2;    //Should be between 2 to 9
////////////////////////////////////////////////////////////////////////

  // Variable declaration
  int outp = 0;
  boolean printLastCommandOnce = false;
  boolean printButtonMenuOnce = false;
  boolean initialPrint = true;
  String allOn = "";
  String allOff = "";
  boolean reading = false;
  boolean readInput[10]; //Create a boolean array for the maximum ammount.

//Beginning of the program
void setup(){
  Serial.begin(9600);

  //Pins 10,11,12 & 13 are used by the ethernet shield
  //Set pins as Outputs
  for (int var = outputLowest; var < outputLowest + outputQuantity; var++)  {
            pinMode(var, OUTPUT);
        }

  //Setting up the IP address. Comment out the one you dont need.
  //Ethernet.begin(mac); //for DHCP address. (Address will be printed to serial.)
  Ethernet.begin(mac, ip, gateway, subnet); //for manual setup. (Address is the one configured above.)


  server.begin();
  Serial.println(Ethernet.localIP());
}


void loop(){

  // listen for incoming clients, and process requests.
  checkForClient();
}


void checkForClient(){

  EthernetClient client = server.available();

  if (client) {

    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    boolean sentHeader = false;

    while (client.connected()) {
      if (client.available()) {

        if(!sentHeader){
         // send a standard http response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connnection: close");
          client.println();
          client.println("<!DOCTYPE HTML>");
          client.println("<head>");
       
          // add page title
          client.println("<title>Ethernet Switching</title>");
          client.println("<meta name=\"description\" content=\"Ethernet Switching\"/>");

          // add a meta refresh tag, so the browser pulls again every 5 seconds:
          client.println("<meta http-equiv=\"refresh\" content=\"10; url=/\">");
       
          // add other browser configuration
          client.println("<meta name=\"apple-mobile-web-app-capable\" content=\"yes\">");
          client.println("<meta name=\"apple-mobile-web-app-status-bar-style\" content=\"default\">");
          client.println("<meta name=\"viewport\" content=\"width=device-width, user-scalable=no\"/>");       
       
          //inserting the styles data, usually found in CSS files.
          client.println("<style type=\"text/css\">");
          client.println("");
       
          //This will set how the page will look graphically
          client.println("html { height:100%; }");

          client.println("  body {");
          client.println("    height: 100%;");
          client.println("    margin: 0;");
          client.println("    font-family: helvetica, sans-serif;");
          client.println("    -webkit-text-size-adjust: none;");
          client.println("   }");
          client.println("");
          client.println("body {");
          client.println("    -webkit-background-size: 100% 21px;");
          client.println("    background-color: #c5ccd3;");
          client.println("    background-image:");
          client.println("    -webkit-gradient(linear, left top, right top,");
          client.println("    color-stop(.75, transparent),");
          client.println("    color-stop(.75, rgba(255,255,255,.1)) );");
          client.println("    -webkit-background-size: 7px;");
          client.println("   }");
          client.println("");
          client.println(".view {");
          client.println("    min-height: 100%;");
          client.println("    overflow: auto;");
          client.println("   }");
          client.println("");
          client.println(".header-wrapper {");
          client.println("    height: 44px;");
          client.println("    font-weight: bold;");
          client.println("    text-shadow: rgba(0,0,0,0.7) 0 -1px 0;");
          client.println("    border-top: solid 1px rgba(255,255,255,0.6);");
          client.println("    border-bottom: solid 1px rgba(0,0,0,0.6);");
          client.println("    color: #fff;");
          client.println("    background-color: #8195af;");
          client.println("    background-image:");
          client.println("    -webkit-gradient(linear, left top, left bottom,");
          client.println("    from(rgba(255,255,255,.4)),");
          client.println("    to(rgba(255,255,255,.05)) ),");
          client.println("    -webkit-gradient(linear, left top, left bottom,");
          client.println("    from(transparent),");
          client.println("    to(rgba(0,0,64,.1)) );");
          client.println("    background-repeat: no-repeat;");
          client.println("    background-position: top left, bottom left;");
          client.println("    -webkit-background-size: 100% 21px, 100% 22px;");
          client.println("    -webkit-box-sizing: border-box;");
          client.println("   }");
          client.println("");
          client.println(".header-wrapper h1 {");
          client.println("    text-align: center;");
          client.println("    font-size: 20px;");
          client.println("    line-height: 44px;");
          client.println("    margin: 0;");
          client.println("   }");
          client.println("");
          client.println(".group-wrapper {");
          client.println("    margin: 9px;");
          client.println("    }");
          client.println("");
          client.println(".group-wrapper h2 {");
          client.println("    color: #4c566c;");
          client.println("    font-size: 17px;");
          client.println("    line-height: 0.8;");
          client.println("    font-weight: bold;");
          client.println("    text-shadow: #fff 0 1px 0;");
          client.println("    margin: 20px 10px 12px;");
          client.println("   }");
          client.println("");
          client.println(".group-wrapper h3 {");
          client.println("    color: #4c566c;");
          client.println("    font-size: 12px;");
          client.println("    line-height: 1;");
          client.println("    font-weight: bold;");
          client.println("    text-shadow: #fff 0 1px 0;");
          client.println("    margin: 20px 10px 12px;");
          client.println("   }");
          client.println("");
          client.println(".group-wrapper table {");
          client.println("    background-color: #fff;");
          client.println("    -webkit-border-radius: 10px;");
       
          client.println("    -moz-border-radius: 10px;");
          client.println("    -khtml-border-radius: 10px;");
          client.println("    border-radius: 10px;");
       
          client.println("    font-size: 17px;");
          client.println("    line-height: 20px;");
          client.println("    margin: 9px 0 20px;");
          client.println("    border: solid 1px #a9abae;");
          client.println("    padding: 11px 3px 12px 3px;");
          client.println("    margin-left:auto;");
          client.println("    margin-right:auto;");
       
          client.println("    -moz-transform :scale(1);"); //Code for Mozilla Firefox
          client.println("    -moz-transform-origin: 0 0;");


       
          client.println("   }");
          client.println("");


          //how the green (ON) LED will look
          client.println(".green-circle {");
          client.println("    display: block;");
          client.println("    height: 23px;");
          client.println("    width: 23px;");
          client.println("    background-color: #0f0;");
        //client.println("    background-color: rgba(60, 132, 198, 0.8);");
          client.println("    -moz-border-radius: 11px;");
          client.println("    -webkit-border-radius: 11px;");
          client.println("    -khtml-border-radius: 11px;");
          client.println("    border-radius: 11px;");
          client.println("    margin-left: 1px;");

          client.println("    background-image: -webkit-gradient(linear, 0% 0%, 0% 90%, from(rgba(46, 184, 0, 0.8)), to(rgba(148, 255, 112, .9)));@");
          client.println("    border: 2px solid #ccc;");
          client.println("    -webkit-box-shadow: rgba(11, 140, 27, 0.5) 0px 10px 16px;");
          client.println("    -moz-box-shadow: rgba(11, 140, 27, 0.5) 0px 10px 16px; /* FF 3.5+ */");
          client.println("    box-shadow: rgba(11, 140, 27, 0.5) 0px 10px 16px; /* FF 3.5+ */");
       
          client.println("    }");
          client.println("");
       
          //how the black (off)LED will look
          client.println(".black-circle {");
          client.println("    display: block;");
          client.println("    height: 23px;");
          client.println("    width: 23px;");
          client.println("    background-color: #040;");
          client.println("    -moz-border-radius: 11px;");
          client.println("    -webkit-border-radius: 11px;");
          client.println("    -khtml-border-radius: 11px;");
          client.println("    border-radius: 11px;");
          client.println("    margin-left: 1px;");
          client.println("    -webkit-box-shadow: rgba(11, 140, 27, 0.5) 0px 10px 16px;");
          client.println("    -moz-box-shadow: rgba(11, 140, 27, 0.5) 0px 10px 16px; /* FF 3.5+ */");
          client.println("    box-shadow: rgba(11, 140, 27, 0.5) 0px 10px 16px; /* FF 3.5+ */");
          client.println("    }");
          client.println("");
       
          //this will add the glare to both of the LEDs
          client.println("   .glare {");
          client.println("      position: relative;");
          client.println("      top: 1;");
          client.println("      left: 5px;");
          client.println("      -webkit-border-radius: 10px;");
          client.println("      -moz-border-radius: 10px;");
          client.println("      -khtml-border-radius: 10px;");
          client.println("      border-radius: 10px;");
          client.println("      height: 1px;");
          client.println("      width: 13px;");
          client.println("      padding: 5px 0;");
          client.println("      background-color: rgba(200, 200, 200, 0.25);");
          client.println("      background-image: -webkit-gradient(linear, 0% 0%, 0% 95%, from(rgba(255, 255, 255, 0.7)), to(rgba(255, 255, 255, 0)));");
          client.println("    }");
          client.println("");
       
       
          //and finally this is the end of the style data and header
          client.println("</style>");
          client.println("</head>");
       
          //now printing the page itself
          client.println("<body>");
          client.println("<div class=\"view\">");
          client.println("    <div class=\"header-wrapper\">");
          client.println("      <h1>Ethernet Switching</h1>");
          client.println("    </div>");
          client.println("<div  class=\"group-wrapper\">");
          client.println("    <h2>Switch the required output.</h2>");
          client.println();
       
          //This is for the arduino to construct the page on the fly.
          sentHeader = true;
        }
     
        char c = client.read();

        if(reading && c == ' '){
          reading = false;
          }
    
//       Serial.print(c);
     
     
        if(c == '?') {
          reading = true; //found the ?, begin reading the info
        }
  

        if(reading){
            if(c == 'H') {outp = 1;}
            if(c == 'L') {outp = 0;}
          Serial.print(c);   //print the value of c to serial communication
          //Serial.print(outp);
          //Serial.print('\n');
      
           switch (c) {
            case '2':
              //add code here to trigger on 2
              triggerPin(2, client, outp);
              break;
            case '3':
            //add code here to trigger on 3
              triggerPin(3, client, outp);
              break;
            case '4':
            //add code here to trigger on 4
              triggerPin(4, client, outp);
              break;
            case '5':
            //add code here to trigger on 5
              triggerPin(5, client, outp);
              //printHtml(client);
              break;
            case '6':
            //add code here to trigger on 6
              triggerPin(6, client, outp);
              break;
            case '7':
            //add code here to trigger on 7
              triggerPin(7, client, outp);
              break;
            case '8':
            //add code here to trigger on 8
              triggerPin(8, client, outp);
              break;
            case '9':
            //add code here to trigger on 9
              triggerPin(9, client, outp);
              break;
          }

        }

        if (c == '\n' && currentLineIsBlank){
          printLastCommandOnce = true;
          printButtonMenuOnce = true;
          triggerPin(777, client, outp); //Call to read input and print menu. 777 is used not to update any outputs
          break;
        }
      }
    }
 
    //Set Variables Before Exiting
    printLastCommandOnce = false;
    printButtonMenuOnce = false;
 
    allOn = "";
    allOff = "";
    client.println("\n<h3 align=\"center\">&copy; Author - Claudio Vella <br> Malta - October - 2012</h3>");
    client.println("</div>\n</div>\n</body>\n</html>");
 
    delay(1); // give the web browser time to receive the data
    client.stop(); // close the connection:

  }

}



void triggerPin(int pin, EthernetClient client, int outp){
//Switching on or off outputs, reads the outputs and prints the buttons

  //Setting Outputs
    if (pin != 777){
        if(outp == 1) {
          digitalWrite(pin, HIGH);
         }
        if(outp == 0){
          digitalWrite(pin, LOW);
         }
    }
  //Refresh the reading of outputs
  readOutputStatuses();


  //Prints the buttons
          if (printButtonMenuOnce == true){
              printHtmlButtons(client);
               printButtonMenuOnce = false;
          }
      
}


//print the html buttons to switch on/off channels
void printHtmlButtons(EthernetClient client){
  
     //Start to create the html table
     client.println("");
     //client.println("<p>");
     client.println("<FORM>");
     client.println("<table border=\"0\" align=\"center\">");
  
     //Start printing button by button
     for (int var = outputLowest; var < outputLowest + outputQuantity; var++)  {   
           
              //set command for all on/off
              allOn += "H";
              allOn += var;
              allOff += "L";
              allOff += var;
           
           
              //Print begining of row
              client.print("<tr>\n");     
           
              //Prints the ON Buttons
              client.print(" <td><INPUT TYPE=\"button\" VALUE=\"Switch ON - Pin  ");
              client.print(var);
              client.print("\" onClick=\"parent.location='/?H");
              client.print(var);
              client.print("'\"></td>\n");
           
              //Prints the OFF Buttons
              client.print(" <td><INPUT TYPE=\"button\" VALUE=\"Switch OFF - Pin  ");
              client.print(var);
              client.print("\" onClick=\"parent.location='/?L");
              client.print(var);
              client.print("'\"></td>\n");
           
           
              //Print first part of the Circles or the LEDs
              if (readInput[var] == true){
                client.print(" <td><div class='green-circle'><div class='glare'></div></div></td>\n");
              }else
              {
                client.print(" <td><div class='black-circle'><div class='glare'></div></div></td>\n");
              }
           
           
              //Print end of row
              client.print("</tr>\n");
         }
      

              //Prints the ON All Pins Button
              client.print("<tr>\n<td><INPUT TYPE=\"button\" VALUE=\"Switch ON All Pins");
              client.print("\" onClick=\"parent.location='/?");
              client.print(allOn);
              client.print("'\"></td>\n");
          
              //Prints the OFF All Pins Button         
              client.print("<td><INPUT TYPE=\"button\" VALUE=\"Switch OFF All Pins");
              client.print("\" onClick=\"parent.location='/?");
              client.print(allOff);
              client.print("'\"></td>\n<td></td>\n</tr>\n");
           
              //Closing the table and form
              client.println("</table>");
              client.println("</FORM>");
              //client.println("</p>");
 
    }

//Reading the Output Statuses
void readOutputStatuses(){
  for (int var = outputLowest; var < outputLowest + outputQuantity; var++)  {
            readInput[var] = digitalRead(var);
            //Serial.print(readInput[var]);
       }

}

Update V4.06

The Ethernet Switching has been revised and updated to include some more features.
This release is Version 4.06
There has been interest from all over the world (Brazil, Croatia, US, UK), some contacting me on these pages and some privately. Many had suggestions, on how can I improve and add some more features, in which, some of them I did.
I would like to thank everyone for the comments and the reviews this article got.
I welcome anyone for comments and suggestions for future features and options.
Below are the features I had added.

Features

    1. To invert the outputs. - Done on V3.06
    2. A possibility to rename the buttons - Done on V4.06
    3. To be password protected. - Not yet done
    4. Refresh page settable. - Done on V3.06
    5  Switch On or Off the outputs on startup - Done on V3.06
    6. Enable/Disable the All on/off buttons - Done on V4.01
    7. Read Temperature - Done on V4.03
    8. Save/Load statuses from eeprom to keep latest status after powercut - Done on V4.06
    9. Option to choose which output to retain the value after power cut. - Done on V4.06


Download link

https://www.dropbox.com/s/19rrxua51v9hhrz/WebServerSwitchingV04_06.ino

Here are some images of the arduino hardware from instructable user sokre666 from Croatia.
Many thanks to this user for the images and the suggestions he had made.