Controlling Appliances Over WiFi And Ethernet

This a simple tutorial on how to setup your Arduino board with Ethernet shield to control your home appliances like Lights or Fans using any device (Mobile/Tablet/Laptop/Desktop) connected to your WiFi network. It is assumed that the reader has gone through the project how to get started with the arduino.

Components Required

Block Diagram

Fig. 1: Block Diagram of Arduino based Wi-Fi Controlled Home Automations System

HTML (Hyper Text Markup Language)

Getting Started

– Go to File menu and click Save As. Below the file name you would see save as type:

Fig. 2: Screenshot of saving webpage on Windows used for controlling home appliances

– Now close the notepad and open the file again using a browser (Mozilla Firefox/ Google Chrome/ IE). You should see something like this.

Fig. 3: Screenshot of a simple HTML webpage

What we wrote above is the basic code.

HTML Tags Explanation

This is a bold text

Some Frequently Used Tags

Empty Tags

<br/> and <hr/> are called empty tags since they don’t have corresponding closing tag. <br/> is used for giving line break (equivalent to hitting enter in a word document) and <hr/> is horizontal rule (shows a visible line when used).

Linking to Other pages

Will give you this:

underlined

Well nothing is good without a good example so let us implement everything we just learned into an example code. Copy paste the following into a notepad, save it as a HTML file and see for yourself in the browser.

This is how the page would look in the browser:

Fig. 4: Screenshot of a simple HTML webpage showing simple text

Now that we have learnt the web interface part, let us move on to the next section.

Hardware Setup -Step by Step

Hardware Setup

1) Gather all the parts shown in the image.

Fig. 5: Image showing components used in design of Wi-Fi controlled Home Automation System

Note 1:  The one I used is an Indian made Arduino clone. Depending on from which manufacturer you bought, it would look different.

Fig. 6: Image of Ethernet Shield for Arduino Uno

Fig. 7: Image showing Ethernet Cable connected to PC

Fig. 8: Image showing Ethernet Cable connected to Wi-Fi Modem

(Skip this step if the Router has already been configured)

5) Now take another Ethernet cable and connect one end to another LAN port of the Wi-Fi router and other end of the same cable to the Ethernet port of the Ethernet shield.

Fig. 9: Image showing LAN cable connected to Ethernet Shield

Fig. 10: Image showing LAN Cable connected to Wi-Fi Modem

Fig. 11: Screenshot of Arduino Serial Port showing Local IP Address

7) Switch ON WiFi on your Phone/Tablet/Laptop and locate the name of the Router (which you assigned earlier) and enter the password if necessary to connect to the network.

Note: My WiFi SSID is “Robots Reloaded”

Fig. 12: Screenshot of Android’s Settings for connecting to Wi-Fi Router

8) Open your browser and go to the address “http://192.168.0.108” (which was assigned in the sketch uploaded into it)

You should see this page in few seconds

Fig. 13: Screenshot of webpage loaded from Local Server

When opened from desktop/Laptop:

Fig. 14: Screenshot of Webpage on a desktop computer

9)  Connect the rest of the circuit as per the circuit diagram.

Arduino Code Explanation & Troubleshooting

Arduino Code Explanation

Troubleshooting

– Problem: Nothing is shown on the serial monitor after implementing step 6

Possible cause:

-Problem: Web page not loading after implementing step 8

Possible cause:

a.       You connected to the wrong WiFi network

b.      The IP Address you dialed doesn’t match the one in the serial monitor

Make sure you are connected to the same WiFi network with correct password and that you have entered the correct IP Address.

– Problem: Web page not loading after implementing step 8

While you click the links, check the serial monitor output. If you see something like this:

Fig. 15: Screenshot of Arduino Serial Port sending commands to control relays

Improvements

Although only single appliance control is shown here, you can create code based on this model  to control any number of appliances through WiFi.

Project Source Code

###

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

int relay = 3;

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };   //physical mac address
byte ip[] = { 192, 168, 0, 108 };         // ip in lan (that's what you need to use in your browser.
 ("192.168.0.108")
byte gateway[] = { 192, 168, 1, 1 };                   // internet access via router
byte subnet[] = { 255, 255, 255, 0 };                  //subnet mask
EthernetServer server(80);                             //server port    
String readString;

void setup() {
// Open serial communications and wait for port to open:
  Serial.begin(9600);
   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }
  pinMode(relay, OUTPUT);
  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip, gateway, subnet);
  server.begin();
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
}


void loop() {
  // Create a client connection
  EthernetClient client = server.available();
  if (client) {
    while (client.connected()) {  
      if (client.available()) {
        char c = client.read();
    
        //read char by char HTTP request
        if (readString.length() < 100) {
          //store characters to string
          readString += c;
          //Serial.print(c);
         }

         //if HTTP request has ended
         if (c == 'n') {         
           Serial.println(readString); //print to serial monitor for debuging
    
           client.println("HTTP/1.1 200 OK"); //send new page
           client.println("Content-Type: text/html");
           client.println();    
           client.println("<HTML>");
           client.println("<HEAD>");

           client.println("<TITLE>WEB INTERFACE</TITLE>");
           client.println("</HEAD>");
           client.println("<BODY>");
           client.println("<center>");
           client.println("WELCOME TO THE WEB INTERFACE OF APPLIANCE CONTROLLER OVER WIFI");
           client.println("<hr />");
           client.println("<br />"); 
           client.println("<H2>Arduino with Ethernet Shield</H2>");
           client.println("<br />"); 
           client.println("<a href="/?relay1on">Switch ON Relay 1</a>");
           client.println("<a href="/?relay1off">Switch OFF Relay 1</a><br />");  
           client.println("<br />");    
           client.println("<br />");
           
           client.println("<p>Created by GANESH SELVARAJ for EngineersGarage.com</p>"); 
           client.println("<br />");
           client.println("</center>");
           client.println("</BODY>");
           client.println("</HTML>");
    
           delay(1);
           //stopping client
           client.stop();
           //controls the Arduino if you press the buttons
           if (readString.indexOf("?relay1on") >0){
               digitalWrite(relay, HIGH);
           }
           if (readString.indexOf("?relay1off") >0){
               digitalWrite(relay, LOW);
           }
         
            //clearing string for next read
            readString=""; 
          
         }
       }
    }
}
}

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Circuit Diagrams

Circuit-Diagram-Arduino-Based-Wi-Fi-Controlled-Home-Automation-System

Project Video

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Filed Under: Electronic Projects
Tagged With: Arduino, Wi-Fi
 

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