You must assign a manual IP address to the laptop and Arduino.
Then include Ethernet.h in your sketch and try to make Ethernet connection. Finally you can see your webpage in your laptop by enter Arduino's IP in your browser. Example:
#include <SPI.h>
#include <Ethernet.h>
/******************** ETHERNET SETTINGS ********************/
byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0x85, 0xD9 }; //physical mac address
byte ip[] = { 192, 168, 1, 172 }; // ip in lan
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
byte gateway[] = { 192, 168, 1, 254 }; // default gateway
EthernetServer server(80); //server port
void setup()
{
Ethernet.begin(mac,ip,gateway,subnet); // initialize Ethernet device
server.begin(); // start to listen for clients
pinMode(8, INPUT); // input pin for switch
}
void loop()
{
EthernetClient client = server.available(); // look for the client
// 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();
/*
This portion is the webpage which will be
sent to client web browser one can use html , javascript
and another web markup language to make particular layout
*/
client.println("<!DOCTYPE html>"); //web page is made using html
client.println("<html>");
client.println("<head>");
client.println("<title>Ethernet Tutorial</title>");
client.println("<meta http-equiv=\"refresh\" content=\"1\">");
/*
The above line is used to refresh the page in every 1 second
This will be sent to the browser as the following HTML code:
<meta http-equiv="refresh" content="1">
content = 1 sec i.e assign time for refresh
*/
client.println("</head>");
client.println("<body>");
client.println("<h1>A Webserver Tutorial </h1>");
client.println("<h2>Observing State Of Switch</h2>");
client.print("<h2>Switch is: </2>");
if (digitalRead(8))
{
client.println("<h3>ON</h3>");
}
else
{
client.println("<h3>OFF</h3>");
}
client.println("</body>");
client.println("</html>");
delay(1); // giving time to receive the data
/*
The following line is important because it will stop the client
and look for the new connection in the next iteration i.e
EthernetClient client = server.available();
*/
client.stop();
}