Home ArduinoArduino Code Switch and LED on and off using the internet

Switch and LED on and off using the internet

by iainhendry71

This requires an ethernet shield and an LED connected to pin 6.

Copy the code into a new sketch and upload it to your arduino and then open your web browser to



//simple button GET server code to control servo and arduino pin 6
//for use with IDE 1.0
//open serial monitor to see what the arduino receives
//use the \ slash to escape the ” in the html
//for use with W5100 based ethernet shields
//Powering a servo from the arduino usually DOES NOT WORK.
//note that the below bug fix may be required
// http://code.google.com/p/arduino/issues/detail?id=605

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

#include <Servo.h>
Servo myservo;  // create servo object to control a servo

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 177 }; // ip in lan
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(){

pinMode(6, OUTPUT); //pin selected to control
//start Ethernet
Ethernet.begin(mac, ip, gateway, subnet);
//the pin for the servo co
//enable serial data print
Serial.println(“server LED test 1.0”); // so I can keep track of what is loaded

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;

//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(“<TITLE>LED on/off</TITLE>”);
client.println(“<H1>LED On/Off</H1>”);
client.println(“<hr />”);
client.println(“<br />”);

client.println(“<a href=\”/?lighton\”\”>Turn On Light</a>”);
client.println(“<a href=\”/?lightoff\”\”>Turn Off Light</a><br />”);


//stopping client

///////////////////// control arduino pin
if(readString.indexOf(“?lighton”) >0)//checks for on
digitalWrite(6, HIGH);    // set pin 4 high
Serial.println(“Led On”);
if(readString.indexOf(“?lightoff”) >0)//checks for off
digitalWrite(6, LOW);    // set pin 4 low
Serial.println(“Led Off”);
//clearing string for next read


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