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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // Set the LCD address to 0x27 for a 16x2 display
const int trigPin = 2;  // D2 on NodeMCU
const int echoPin = 15;  // D4 on NodeMCU
const int buzzerPin = 5; // D13 on NodeMCU

void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  lcd.print("Distance: ");
  lcd.setCursor(0, 1);
}

void loop() {
  long duration, distance;
  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = (duration / 2) / 29.1;  // Calculate distance in cm

  lcd.setCursor(10, 0);
  lcd.print("    ");  // Clear previous distance
  lcd.setCursor(10, 0);
  lcd.print(distance);
  lcd.print(" cm");

  if (distance < 10) {
    digitalWrite(buzzerPin, HIGH); // Turn on the buzzer
    lcd.setCursor(0, 1);
    lcd.print("Side"); // Display "Side" when distance is less than 10 cm
  } else {
    digitalWrite(buzzerPin, LOW); // Turn off the buzzer
    lcd.setCursor(0, 1);
    lcd.print("Go"); // Display "Go" when distance is 10 cm or more
  }
  delay(100);
}