C


// Alternately Blink Digital Pins 9 and 10

void setup() {
  pinMode( 9, OUTPUT);
  pinMode(10, OUTPUT);
} //setup

void loop() {
  digitalWrite( 9, HIGH);  // LED on
  digitalWrite(10, LOW);   // LED off
  delay(1000);             // wait 1 second

  digitalWrite( 9, LOW);   // LED off
  digitalWrite(10, HIGH);  // LED on
  delay(1000);             // wait 1 second
} //loop
Digital Output to 2 LEDs
