const int NUM_PARKING_SPACES = 3;

const int ECHO_PINS[NUM_PARKING_SPACES] = {15, 5, 26}; 
const int TRIG_PINS[NUM_PARKING_SPACES] = {2, 18, 27}; 
const int LED_PINS[NUM_PARKING_SPACES] = {13, 12, 14}; 

bool parkingSpaces[NUM_PARKING_SPACES] = {false, false, false};

void setup() {
  Serial.begin(115200);

  for (int i = 0; i < NUM_PARKING_SPACES; i++) {
    pinMode(ECHO_PINS[i], INPUT);
    pinMode(TRIG_PINS[i], OUTPUT);
    pinMode(LED_PINS[i], OUTPUT);
  }
}

float readDistanceCM(int TRIG_PIN, int ECHO_PIN) {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2 ;
}

// Data structure to keep track of the parking space status
void updateParkingStatus() {
  for (int i = 0; i < NUM_PARKING_SPACES; i++) {
    int distance = readDistanceCM(TRIG_PINS[i], ECHO_PINS[i]);
    parkingSpaces[i] = (distance < 200.0);
    digitalWrite(LED_PINS[i], parkingSpaces[i]);
  }
}

void loop() {
  updateParkingStatus();

  Serial.println("Parking Space Status:");

  for (int i = 0; i < NUM_PARKING_SPACES; i++) {
    Serial.print("Space ");
    Serial.print(i + 1);
    Serial.print(": ");
    Serial.println(parkingSpaces[i] ? "Occupied" : "Available");
  }

  delay(1000);
}