Random Blink

Forum 2005-2010 (read only) General Frequently-Asked Questions
3

Try this -

/*

  • Blink_Randomly
  • Modified from the basic Arduino example. Turns an LED on for a random time,
  • then off for a (most likely) different random time. We use pin 13 because,
  • depending on your Arduino board, it has either a built-in LED
  • or a built-in resistor so that you need only an LED.
  • Original at - http://www.arduino.cc/en/Tutorial/Blink
    */

int ledPin = 13; // LED connected to digital pin 13
long randOn = 0; // Initialize a variable for the ON time
long randOff = 0; // Initialize a variable for the OFF time

void setup() // run once, when the sketch starts
{
randomSeed (analogRead (0)); // randomize
pinMode(ledPin, OUTPUT); // sets the digital pin as output
}

void loop() // run over and over again
{
randOn = random (100, 1200); // generate ON time between 0.1 and 1.2 seconds
randOff = random (200, 900); // generate OFF time between 0.2 and 0.9 seconds
digitalWrite(ledPin, HIGH); // sets the LED on
delay(randOn); // waits for a random time while ON
digitalWrite(ledPin, LOW); // sets the LED off
delay(randOff); // waits for a random time while OFF
}

Hope this helps.

D