DCC Block Occupancy Detector

// Current-based occupancy detection
const int SENSOR_PIN = A0;
const int THRESHOLD = 50;
const int LED_PIN = 13;

int baseline = 0;

void setup() {
  Serial.begin(9600);
  pinMode(LED_PIN, OUTPUT);
  // Calibrate with no load
  baseline = analogRead(SENSOR_PIN);
}

void loop() {
  int reading = analogRead(SENSOR_PIN);
  int current = abs(reading - baseline);
  
  if (current > THRESHOLD) {
    digitalWrite(LED_PIN, HIGH);
    Serial.println("OCCUPIED");
  } else {
    digitalWrite(LED_PIN, LOW);
    Serial.println("CLEAR");
  }
  delay(100);
}