Interfacing of Led With Arduino:

Led ( Light emitting diode) : Light Emitting Diodes are the mostly commonly used components in many applications. They are made of semiconducting material. This article describes about basic interfacing of LEDs to the 8051 family microcontrollers.

int led1 = 13;

int led2 = 12;

int led3 = 11;

int led4 = 10;// the setup routine runs once when you press reset:

void setup() { // initialize the digital pin as an output.

pinMode(led1, OUTPUT);

pinMode(led2, OUTPUT);

pinMode(led3, OUTPUT);

pinMode(led4, OUTPUT);}// the loop routine runs over and over again forever:

void loop() {

digitalWrite(led1, HIGH);

digitalWrite(led2, LOW);

digitalWrite(led3, HIGH);

digitalWrite(led4, LOW); // turn the LED on (HIGH is the voltage level)

delay(1000); // wait for a second

digitalWrite(led1, LOW);

digitalWrite(led2, HIGH);

digitalWrite(led4, HIGH);

digitalWrite(led3, LOW);// turn the LED off by making the voltage LOW

delay(1000); // wait for a second}