#include <LiquidCrystal_I2C.h>
#include <Servo.h>
#include <NewPing.h>

// Define LCD I2C address
LiquidCrystal_I2C lcd(0x27, 16, 2); // Adjust address if necessary

// Define ultrasonic sensor pins and NewPing setup
#define TRIGGER_PIN_1 2
#define ECHO_PIN_1 3
#define TRIGGER_PIN_2 4
#define ECHO_PIN_2 5
#define TRIGGER_PIN_3 6
#define ECHO_PIN_3 7
#define MAX_DISTANCE 200 // Maximum distance in cm

NewPing sonar1(TRIGGER_PIN_1, ECHO_PIN_1, MAX_DISTANCE);
NewPing sonar2(TRIGGER_PIN_2, ECHO_PIN_2, MAX_DISTANCE);
NewPing sonar3(TRIGGER_PIN_3, ECHO_PIN_3, MAX_DISTANCE);

// Define servo motor pin
const int servoPin = 9;

// Create Servo object
Servo myservo;

// Define threshold distance (in cm) to detect a vehicle
const int thresholdDistance = 30; // Adjust this value based on your setup

// Define number of parking slots
const int numSlots = 3;

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Parking Status:");
  myservo.attach(servoPin);
  myservo.write(0); // Set servo to initial position (0 degrees)
}

void loop() {
  int availableSlots = 0;
  int availableSlotIndex = -1; // Store index of the first available slot

  // Measure distances using NewPing library
  unsigned int distance1 = sonar1.ping_cm();
  unsigned int distance2 = sonar2.ping_cm();
  unsigned int distance3 = sonar3.ping_cm();

  // Check each sensor and count available slots
  if (distance1 > thresholdDistance) {
    availableSlots++;
    availableSlotIndex = 0;
  }
  if (distance2 > thresholdDistance) {
    availableSlots++;
    if (availableSlotIndex == -1) availableSlotIndex = 1;
  }
  if (distance3 > thresholdDistance) {
    availableSlots++;
    if (availableSlotIndex == -1) availableSlotIndex = 2;
  }

  // Control servo and LCD display
  if (availableSlots > 0) {
    myservo.write(90); // Move servo to 90 degrees
    lcd.setCursor(0, 1);
    lcd.print("Available: Slot ");
    lcd.print(availableSlotIndex + 1);
  } else {
    myservo.write(0); // Keep servo at 0 degrees if no slots are available
    lcd.setCursor(0, 1);
    lcd.print("No slots available");
  }

  Serial.print("Available Slots: ");
  Serial.println(availableSlots);
  delay(200);
}