Blink a LED

  Turns on an LED on for one second, then off for one second, repeatedly

  

     Most  Arduinos  have an on-board  LED  you can control. On the Uno and

  On other  Arduino  board, it is attached to digital pin 13. If you're unsure what

  pin the on-board LED is connected to on your Arduino model, check

Circuit Diagram :

The code is :

// the setup function runs once when you press reset or power the board

void setup() {

  // initialize digital pin 13 as an output.

  pinMode(13, OUTPUT);

}

// the loop function runs over and over again forever

void loop() {

  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)

  delay(1000);              // wait for a second

  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW

  delay(1000);              // wait for a second

}

Video Tutorial :