#include <LiquidCrystal.h>
#include <Servo.h>

#define TRIG_PIN 9
#define ECHO_PIN 10
#define LED_PIN 11
#define BUZZER_PIN 12
#define SERVO_PIN 13
#define BUTTON_PIN 2

LiquidCrystal lcd(7, 8, 4, 5, 6, 3);
Servo myServo;

const int threshold = 100;

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  myServo.attach(SERVO_PIN);
  lcd.begin(16, 2);
  lcd.print("Water Level:");
}

void loop() {
  // Measure water level
  long duration, distance;
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = (duration / 2) / 29.1; // Convert to cm
  
  // Display on LCD
  lcd.setCursor(0, 1);
  lcd.print(distance);
  lcd.print(" cm      ");
  
  // Check threshold
  if (distance < threshold) {
    digitalWrite(LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
    myServo.write(90); // Turn servo to 90 degrees
  } else {
    digitalWrite(LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);
    myServo.write(0); // Turn servo back to 0 degrees
  }
  
  // Manual button press
  if (digitalRead(BUTTON_PIN) == LOW) {
    digitalWrite(LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);
    myServo.write(90); // Turn servo to 90 degrees
    delay(50); // Debounce delay
  }

  delay(50);
}