/* Arduino Projects for Dummies
 * by Brock Craft 
 *
 * Chapter 4: The All-Seeing Eye
 * Sequentially lights up a series of LEDs
 *
 * v0.1 30.04.2013
*/

// A variable to set a delay time between each LED
int timeDelay(40); 

// A variable to store which LED we are currently working on
int currentLED = 4;

// A variable to store the direction of travel of LEDs
int dir = 1;

// A variable to store the last time we changed something
unsigned long timeChanged = 0;

// Create an array to hold the value for each LED pin
byte ledPin[] = {4, 5, 6, 7, 8, 9, 10, 11, 12, 13};

void setup() {
  // Set all pins for OUTPUT
  for (int x=0; x<10; x++) {
    pinMode(ledPin[x], OUTPUT); 
  }

 // Set up the 
  timeChanged = millis();
}

void loop() {
  // Check whether it has been long enough
  if ((millis() - timeChanged) > timeDelay) {

    // Turn off all of the LEDs
    for (int x=0; x<10; x++) {
      digitalWrite(ledPin[x], LOW);
    }

    // Turn on the current LED
    digitalWrite(ledPin[currentLED], HIGH);

    // Increment by the direction value
    currentLED += dir;

    // If we are at the end of a row, change direction
    if (currentLED == 9) {
      dir = -1;
    }
    if (currentLED == 0) {
      dir = 1;
    }
  }

  // Store the current time as the time we last changed LEDs
  timeChanged = millis();
}