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

#define TRIG_PIN 12
#define ECHO_PIN 13
#define LED_PIN_1 16
#define LED_PIN_2 17
#define LED_PIN_3 18
#define LED_PIN_4 19

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Set the LCD address and dimensions

void setup() {
  Serial.begin(9600);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN_1, OUTPUT);
  pinMode(LED_PIN_2, OUTPUT);
  pinMode(LED_PIN_3, OUTPUT);
  pinMode(LED_PIN_4, OUTPUT);
  lcd.init();
  lcd.backlight();
}

void loop() {
  long duration, distance_cm, distance_inches;
  float distance_m, distance_km;
  
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  duration = pulseIn(ECHO_PIN, HIGH);
  distance_cm = duration / 58; // Divide by 58 to convert microseconds to centimeters
  distance_inches = duration / 148; // Divide by 148 to convert microseconds to inches
  distance_m = distance_cm / 100.0; // Convert centimeters to meters
  distance_km = distance_m / 1000.0; // Convert meters to kilometers
  
  Serial.print("Distance: ");
  Serial.print(distance_cm);
  Serial.print(" cm, ");
  Serial.print(distance_inches);
  Serial.print(" inches, ");
  Serial.print(distance_m);
  Serial.print(" m, ");
  Serial.print(distance_km);
  Serial.println(" km");
  
  // Control LEDs based on distance
  if (distance_cm < 10) {
    digitalWrite(LED_PIN_1, HIGH);
    digitalWrite(LED_PIN_2, HIGH);
    digitalWrite(LED_PIN_3, HIGH);
    digitalWrite(LED_PIN_4, HIGH);
  } else if (distance_cm < 20) {
    digitalWrite(LED_PIN_1, HIGH);
    digitalWrite(LED_PIN_2, HIGH);
    digitalWrite(LED_PIN_3, HIGH);
    digitalWrite(LED_PIN_4, LOW);
  } else if (distance_cm < 30) {
    digitalWrite(LED_PIN_1, HIGH);
    digitalWrite(LED_PIN_2, HIGH);
    digitalWrite(LED_PIN_3, LOW);
    digitalWrite(LED_PIN_4, LOW);
  } else if (distance_cm < 40) {
    digitalWrite(LED_PIN_1, HIGH);
    digitalWrite(LED_PIN_2, LOW);
    digitalWrite(LED_PIN_3, LOW);
    digitalWrite(LED_PIN_4, LOW);
  } else {
    digitalWrite(LED_PIN_1, LOW);
    digitalWrite(LED_PIN_2, LOW);
    digitalWrite(LED_PIN_3, LOW);
    digitalWrite(LED_PIN_4, LOW);
  }
  
  // Display distance on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance_cm);
  lcd.print(" cm");
  
  delay(1000);
}