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

#define ECHO_PIN 2
#define TRIG_PIN 3

// Initialize the LCD (I2C address 0x27, 16 columns, 2 rows)
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  Serial.begin(115200);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  // Initialize the LCD with column and row count
  lcd.begin(16, 2);
  lcd.backlight();
}

float readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2; // Convert duration to distance in cm
}

void loop() {
  float distance = readDistanceCM();
  bool isNearby = distance < 100;
  digitalWrite(LED_BUILTIN, isNearby);
  
  // Print distance to Serial Monitor
  Serial.print("Target Distance: ");
  Serial.println(distance);

  // Display distance on the LCD
  lcd.setCursor(0, 0); // First line
  lcd.print("Distance: ");
  lcd.setCursor(0, 1); // Second line
  lcd.print(distance);
  lcd.print(" cm    "); // Extra spaces to clear previous data

  delay(100);
}