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WiFi Web Server LED Blink
A simple web server that lets you blink an LED via the web.
This sketch will print the IP address of your WiFi Shield (once connected)
to the Serial monitor. From there, you can open that address in a web browser
to turn on and off the LED on pin 9.
If the IP address of your shield is yourAddress:
http://yourAddress/H turns the LED on
http://yourAddress/L turns it off
This example is written for a network using WPA encryption. For
WEP or WPA, change the Wifi.begin() call accordingly.
* WiFi shield attached
* LED attached to pin 9
created 25 Nov 2012
by Tom Igoe
#include <SPI.h>
#include <WiFi.h>
char ssid[] = "yourNetwork"; // your network SSID (name)
char pass[] = "secretPassword"; // your network password
int keyIndex = 0; // your network key Index number (needed only for WEP)
int status = WL_IDLE_STATUS;
WiFiServer server(80);
void setup() {
Serial.begin(9600); // initialize serial communication
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
pinMode(10, OUTPUT); // beep (horn for car)
pinMode(13, OUTPUT); // led to confirm the webserve is up
// check for the presence of the shield:
if (WiFi.status() == WL_NO_SHIELD) {
Serial.println("WiFi shield not present");
while (true); // don't continue
String fv = WiFi.firmwareVersion();
if ( fv != "1.1.0" )
Serial.println("Please upgrade the firmware");
// attempt to connect to Wifi network:
while ( status != WL_CONNECTED) {
Serial.print("Attempting to connect to Network named: ");
Serial.println(ssid); // print the network name (SSID);
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
server.begin(); // start the web server on port 80
printWifiStatus(); // you're connected now, so print out the status
void loop() {
digitalWrite(13, HIGH);
WiFiClient client = server.available(); // listen for incoming clients
if (client) { // if you get a client,
Serial.println("new client"); // print a message out the serial port
String currentLine = ""; // make a String to hold incoming data from the client
while (client.connected()) { // loop while the client's connected
if (client.available()) { // if there's bytes to read from the client,
char c =; // read a byte, then
Serial.write(c); // print it out the serial monitor
if (c == '\n') { // if the byte is a newline character
// if the current line is blank, you got two newline characters in a row.
// that's the end of the client HTTP request, so send a response:
if (currentLine.length() == 0) {
// HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
// and a content-type so the client knows what's coming, then a blank line:
client.println("HTTP/1.1 200 OK");
// the content of the HTTP response follows the header:
client.print("<html> <head> <title>Page Title</title> <style type='text/css'> td{ font-size: 80px !important; color: grey; } </style> </head> <body> <table> <tr> <td></td> <td class='forward'>&#8593;</td> <td></td> </tr> <tr> <td class='left'>&#8592;</td> <td></td> <td class='right'>&#8594;</td> </tr> <tr> <td></td> <td class='back'>&#8595;</td> <td></td> </tr> </table> <!-- js --> <script src='' type='text/javascript'></script> <script type='text/javascript'> document.onkeydown = checkKey; function checkKey(e) { e = e || window.event; if (e.keyCode == '13') { get('stop'); } else if (e.keyCode == '32') { get('beep'); } else if (e.keyCode == '38') { get('forward'); } else if (e.keyCode == '40') { get('back'); } else if (e.keyCode == '37') { get('left'); } else if (e.keyCode == '39') { get('right'); } } function get(direction){ $.get( direction ); $('td').css('color','grey'); $('.' + direction).css('color','black'); } </script> </body> </html>");
// The HTTP response ends with another blank line:
// break out of the while loop:
else { // if you got a newline, then clear currentLine:
currentLine = "";
else if (c != '\r') { // if you got anything else but a carriage return character,
currentLine += c; // add it to the end of the currentLine
if (currentLine.endsWith("GET /forward")) {
digitalWrite(4, LOW);
digitalWrite(5, HIGH);
digitalWrite(6, LOW);
digitalWrite(7, HIGH);
if (currentLine.endsWith("GET /back")) {
digitalWrite(4, HIGH);
digitalWrite(5, LOW);
digitalWrite(6, HIGH);
digitalWrite(7, LOW);
if (currentLine.endsWith("GET /left")) {
digitalWrite(4, LOW);
digitalWrite(5, HIGH);
digitalWrite(6, LOW);
digitalWrite(7, LOW);
if (currentLine.endsWith("GET /right")) {
digitalWrite(4, LOW);
digitalWrite(5, LOW);
digitalWrite(6, LOW);
digitalWrite(7, HIGH);
if (currentLine.endsWith("GET /stop")) {
digitalWrite(4, LOW);
digitalWrite(5, LOW);
digitalWrite(6, LOW);
digitalWrite(7, LOW);
if (currentLine.endsWith("GET /beep")) {
digitalWrite(10, HIGH);
digitalWrite(10, LOW);
// close the connection:
Serial.println("client disonnected");
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
// print your WiFi shield's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.println(" dBm");
// print where to go in a browser:
Serial.print("To see this page in action, open a browser to http://");