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This example is for Wiring version 0024+. 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.

Swing LEDs by BARRAGAN http://barraganstudio.com
Demonstrates the use of digital pins to turn on one light (LED) at a time in a row of 8 one after the other.

    int which = 0;              // variable the keeps which light must be turn on next

    void setup()
    {
      for(int i=0; i<8; i++) {  // initializes pins 0 to 7 as outputs
        pinMode(i, OUTPUT);
      }
    }

    void loop()
    {
      turn_all_off();              // turns all lights off
      digitalWrite(which, HIGH);   // sets on the current light on
      delay(200);                  // waits for 200 milli seconds
      which = which + 1;           // increment the variable to turn on the next one next time
      if(which > 7)                // check for the range, if greater then 7 goes back to 0
      {
        which = 0;
      }
    }

    void turn_all_off() {      // function to turn off all the lights
      int i;                   // connected to digital pins 0 to 7
      for(i=0; i<8; i++) {
        digitalWrite(i, LOW);
      }
    }