My Arduino samples.

MyBlink.ino

/*
  Ed's Blinker Sample
  Turns on two LEDs for five seconds, then off for one second, repeatedly.
  The led on pin 11 alternates between red and green indicating if the 
  circuit is switched on or off.
  
  This is a hack of the default blink example from Arduino.
 
 */
 
// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led_gnd = 10;
int led_1 = 11;
int led_2 = 12;
int led_3 = 13;


// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(led_1, OUTPUT);     
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_gnd, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led_1, HIGH);    // turn the LEDs on (HIGH is the voltage level)
  digitalWrite(led_2, HIGH);
  digitalWrite(led_3, HIGH);
  digitalWrite(led_gnd, LOW);   // Grnd pin forces led_1 to be green

  delay(5000);                  // wait for five seconds

  digitalWrite(led_1, LOW);     // turn the LEDs off by making the voltage LOW
  digitalWrite(led_2, LOW);
  digitalWrite(led_3, LOW);
  digitalWrite(led_gnd, HIGH);  // Making the grnd high reverses the current
                                // turning the led_1 red.

  delay(5000);                  // wait for five second
}