Description

I had my LED have a shorter delay (1/2 a second) between blinks for a more "urgent" display.

Components Used

• Light Emitting Diode (LED)
• Resistor

Arduino Code

/*
 Blink - DR modified
 
 Turns on an LED on for one second, then off for one second, repeatedly.
 
 The circuit:
 * LED connected from digital pin 13 to ground.
 
 Created 4 September 2009
 By David Rolnitzky
 
 based on an orginal by H. Barragan for the Wiring i/o board
 and original "blink" example here:  http://arduino.cc/en/Tutorial/Blink
 
 */

int ledPin =  13;    // LED connected to digital pin 13

// The setup() method runs once, when the sketch starts

void setup()   {                
 // initialize the digital pin as an output:
 pinMode(ledPin, OUTPUT);     
}

// the loop() method runs over and over again,
// as long as the Arduino has power

void loop()                     
{
 digitalWrite(ledPin, HIGH);   // set the LED on
 delay(500);                  // wait for a half second
 digitalWrite(ledPin, LOW);    // set the LED off
 delay(500);                  // wait for a half second
 digitalWrite(ledPin, HIGH);   // set the LED on
 delay(500);                  // wait for a half second
 digitalWrite(ledPin, LOW);    // set the LED off
 delay(500);                  // wait for a half second
}