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

int TRIG_PIN  = 13;  
int ECHO_PIN  = 12;  
int SERVO_PIN = 11;

int DISTANCE_THRESHOLD = 350;
float WATER_LEVEL_OFFSET = 20.0;

LiquidCrystal_I2C lcd(0x27, 16, 2); 

float duration, distance, waterlevel;

Servo servo;

void setup() {
  Serial.begin(9600);

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.print("Distance:");
  lcd.setCursor(0, 1);
  lcd.print("Level:");

  // Setup pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  servo.attach(SERVO_PIN);
  servo.write(0);
}
void loop() {
  // Trigger ultrasonic sensor
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Read distance and calculate water level
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.017;
  waterlevel = distance - WATER_LEVEL_OFFSET;

  // Control servo based on water level
  if (waterlevel < DISTANCE_THRESHOLD) {
    int servo_position = map(waterlevel, 0, DISTANCE_THRESHOLD, 0, 180);
    servo.write(servo_position);
  }

  // Display distance and level on LCD
  lcd.setCursor(9, 0);
  lcd.print("    "); // Clear previous distance value
  lcd.setCursor(9, 0);
  lcd.print(distance);

  lcd.setCursor(6, 1);
  lcd.print("    "); // Clear previous level value
  lcd.setCursor(6, 1);
  lcd.print(waterlevel);

  // Print to Serial Monitor for debugging
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.print("m Level: ");
  Serial.print(waterlevel);
  Serial.println("m");
  Serial.println(" ");
  delay(500);
}