1.2 Let There Be Light.ino

// This is a comment - anything on a line after "//" is ignored
// by the computer.

/* This is also a comment - this one can be multi-line, but it
   must start and end with these characters */

// You must "declare" variables before you use them, 
// so that the program knows about them.
int ledPin1 = 7;
int ledPin2 = 8;

// The setup() function is a function that will be
// called once at the beginning of a program
// We usually set up the initial state of the program here
void setup(){
  // we call the pinMode() function to declare the LED pins
  // as outputs 
  pinMode(ledPin1,OUTPUT);
  pinMode(ledPin2,OUTPUT);
}

// The loop() function will be called in an endless loop
// Your main program code will be in here
void loop(){
  digitalWrite(ledPin1, HIGH); // turn LED1 on
  digitalWrite(ledPin2, LOW);  // turn LED2 of
  // wait for a quarter second before changing the light
  delay(250);
  digitalWrite(ledPin1, LOW);  // turn LED1 off
  digitalWrite(ledPin2, HIGH); // turn LED2 on
  // wait for a quarter second before changing the light
  delay(250);
}