Arduino sketch for a slide scanner using a GAF 503 slide projector and a Canon 20D camera

scanner.ino

int NUM_SLIDES = 50;

// Pin 2 has a slide projector connected
int PROJECTOR_ADVANCE_PIN = 2;
int CAMERA_FOCUS_PIN = 3;
int CAMERA_SHUTTER_PIN = 4;
int ARDUINO_LED_PIN = 13;

// the setup routine runs once when you press reset:
void setup() {                
  pinMode(PROJECTOR_ADVANCE_PIN, OUTPUT);
  digitalWrite(PROJECTOR_ADVANCE_PIN, HIGH);  //.Relay is active-low
  
  pinMode(CAMERA_FOCUS_PIN, OUTPUT);
  digitalWrite(CAMERA_FOCUS_PIN, LOW);
  
  pinMode(CAMERA_SHUTTER_PIN, OUTPUT);
  digitalWrite(CAMERA_SHUTTER_PIN, LOW);
  
  pinMode(ARDUINO_LED_PIN, OUTPUT);
  digitalWrite(ARDUINO_LED_PIN, LOW);
  delay(10000);
}

void loop() {
  digitalWrite(ARDUINO_LED_PIN, HIGH);
  for  (int i = 0; i <= NUM_SLIDES; ++i) {
    digitalWrite(PROJECTOR_ADVANCE_PIN, LOW);
    delay(1000);
    digitalWrite(PROJECTOR_ADVANCE_PIN, HIGH);
    delay(2000);
    
    digitalWrite(CAMERA_FOCUS_PIN, HIGH);
    delay(500);
    digitalWrite(CAMERA_SHUTTER_PIN, HIGH);
    delay(500);
    digitalWrite(CAMERA_SHUTTER_PIN, LOW);
    digitalWrite(CAMERA_FOCUS_PIN, LOW);
    
    delay(500);
  }
  digitalWrite(ARDUINO_LED_PIN, LOW);
  
  while  (1);
}