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This example is for Wiring version 1.0 build 0100+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Led blink using millis() by BARRAGAN http://barraganstudio.com
Demonstrates how to blink an LED at an interval rate using a timer For the Wiring boards v1 the on-board LED is on pin 48, on Wiring S the on-board LED is on pin 15.

    int status = LOW; // led status, initially LOW
    unsigned long previousTime; // timer variable
    int interval = 5000; // interval for blinking 5 seconds

    void setup()
    {
      pinMode(WLED, OUTPUT);
      previousTime = millis();  // mark the time
    }

    void loop()
    {
      // if current time - previousTime is greater than 5 seconds
      // change the LED status
      if ((millis() - previousTime) > interval)
      {
        // invert the LED status
        if (status == LOW)
        {
          status = HIGH;
        }
        else
        {
          status = LOW;
        }
        digitalWrite(WLED, status);
        previousTime = millis(); // mark the time
      }
    }