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

const int trigPin = 3;           // Ultrasonic sensor trigger pin
const int echoPin = 2;           // Ultrasonic sensor echo pin
const int servoPin = 9;          // Digital pin for servo motor

Servo myservo;  // create servo object to control the servo
LiquidCrystal_I2C lcd(0x27, 20, 4); // I2C address 0x27, 20 columns, 4 rows

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  myservo.attach(servoPin);

  lcd.init();          // Initialize LCD
  lcd.backlight();     // Turn on the backlight
}

void loop() {
  float distance = measureDistance();

  // Display information on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance);

  // Check the distance threshold to close the valve
  if (distance <= 25) {
    closeValve();
  } else {
    openValve();
  }

  delay(1000);  // Adjust delay based on your project requirements
}

void openValve() {
  myservo.write(0);  // Open the valve position
}

void closeValve() {
  myservo.write(90);  // Close the valve position
}

float measureDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  return pulseIn(echoPin, HIGH) * 0.034 / 2;
}