Arduino sketch for project #2

Arduino_project2.ino

/*     ---------------------------------------------------------
 *     |  Arduino Experimentation Kit Example Code             |
 *     |  CIRC-02 .: 8 LED Fun :. (Multiple LEDs)   |
 *     ---------------------------------------------------------
 *  
 *  A few Simple LED animations
 *
 * For more information on this circuit http://tinyurl.com/d2hrud
 *
 */
 
//LED Pin Variables
int ledPins[] = {2,3,4,5,6,7,8,9}; //An array to hold the pin each LED is connected to
                                   //i.e. LED #0 is connected to pin 2, LED #1, 3 and so on
                                   //to address an array use ledPins[0] this would equal 2
                                   //and ledPins[7] would equal 9
 
/*
 * setup() - this function runs once when you turn your Arduino on
 * We the three control pins to outputs
 */
void setup()
{
  
  //Set each pin connected to an LED to output mode (pulling high (on) or low (off)
  for(int i = 0; i < 8; i++){         //this is a loop and will repeat eight times
      pinMode(ledPins[i],OUTPUT); //we use this to set each LED pin to output
  }                                   //the code this replaces is below
 
  /* (commented code will not run)
   * these are the lines replaced by the for loop above they do exactly the
   * same thing the one above just uses less typing
  pinMode(ledPins[0],OUTPUT);
  pinMode(ledPins[1],OUTPUT);
  pinMode(ledPins[2],OUTPUT);
  pinMode(ledPins[3],OUTPUT);
  pinMode(ledPins[4],OUTPUT);
  pinMode(ledPins[5],OUTPUT);
  pinMode(ledPins[6],OUTPUT);
  pinMode(ledPins[7],OUTPUT);
  (end of commented code)*/
}
 
 
/*
 * loop() - this function will start after setup finishes and then repeat
 * we call a function called oneAfterAnother(). if you would like a different behaviour
 * uncomment (delete the two slashes) one of the other lines
 */
void loop()                     // run over and over again
{
  //oneAfterAnotherNoLoop();   //this will turn on each LED one by one then turn each off
  //oneAfterAnotherLoop();   //does the same as oneAfterAnotherNoLoop but with 
                             //much less typing
  //oneOnAtATime();          //this will turn one LED on then turn the next one
                             //on turning the 
                             //former off (one LED will look like it is scrolling 
                             //along the line
  inAndOut();              //lights the two middle LEDs then moves them out then back 
                             //in again
}
 
/*
 * inAndOut() - This will turn on the two middle LEDs then the next two out
 * making an in and out look
 */
void inAndOut(){
  int delayTime = 300; //the time (in milliseconds) to pause between LEDs
                       //make smaller for quicker switching and larger for slower
  
  //runs the LEDs out from the middle
  for(int i = 0; i <= 3; i++){
    int offLED = i - 1;  //Calculate which LED was turned on last time through
    if(i == 0) {         //for i = 1 to 7 this is i minus 1 (i.e. if i = 2 we will
      offLED = 3;        //turn on LED 2 and off LED 1)
    }                    //however if i = 0 we don't want to turn of led -1 (doesn't exist)
                         //instead we turn off LED 7, (looping around)
    int onLED1 = 2 - i;       //this is the first LED to go on ie. LED #3 when i = 0 and LED
                    // 
                             //#0 when i = 3 
    int onLED2 = 4 + i;       //this is the first LED to go on ie. LED #4 when i = 0 and LED
                    // 
                             //#7 when i = 3 
    int offLED1 = 3 - offLED; //turns off the LED we turned on last time
    int offLED2 = 4 + offLED; //turns off the LED we turned on last time
    
    digitalWrite(ledPins[onLED1], HIGH);
    digitalWrite(ledPins[onLED2], HIGH);    
    digitalWrite(ledPins[offLED1], LOW);    
    digitalWrite(ledPins[offLED2], LOW);        
    delay(delayTime);
  }
}