#include <LiquidCrystal_I2C.h>


#define PIN_TRIG 4
#define PIN_ECHO 2
#define Led_pin 5

#define addr_12c 0x27
#define lcd_col 16
#define lcd_line 2

LiquidCrystal_I2C lcd(addr_12c, lcd_col, lcd_line);


void setup() {
  Serial.begin(115200);

  lcd.init();
  lcd.backlight();
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);
  pinMode(Led_pin, OUTPUT);
 
}

void loop() {
  // Start a new measurement:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Read the result:
  int duration = pulseIn(PIN_ECHO, HIGH);
  int distance = duration / 58;
  Serial.print("Distance in CM: ");
  Serial.println(distance);

  lcd.setCursor(0,0);
  lcd.print("Distance: ");
  lcd.print(distance);

  if (distance  < 50) {
    tone(14, 262, 250);
    digitalWrite(Led_pin, HIGH);
    delay(1000);
    digitalWrite(Led_pin, LOW);

  }

  delay(1000);
}