Project 5, Chapter 3 LED chasing effect

Here are the comments for the code:

// Project 5 - LED Chase Effect

byte ledPin[] = {4, 5, 6, 7, 8, 9, 10, 11, 12, 13}; // Create array for LED pins

int ledDelay(65); // delay between changes

int direction = 1; //starting direction

int currentLED = 0; //the current LED 

unsigned long changeTime; //stores a 32-bit variable

void setup() {

  //starts the sketch

for (int x=0; x<10; x++) { // set all pins to output

pinMode(ledPin[x], OUTPUT); }//for numbers less than 10, the pinMode increases by 1.

changeTime = millis();//time changes by milliseconds

}

void loop() {

  //loops the sketch

if ((millis() - changeTime) > ledDelay) { // if it has been ledDelay ms since last change

changeLED();

//function that's defined below

changeTime = millis();

}

}

void changeLED() {

for (int x=0; x<10; x++) { // turn off all LED's

digitalWrite(ledPin[x], LOW);

}

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

currentLED += direction; // increment by the direction value

// change direction if we reach the end

if (currentLED == 9) {direction = -1;}//once the LED reaches the last position it goes back the other way

if (currentLED == 0) {direction = 1;}//once it reaches the first position, it goes the other way

}