#include<Arduino.h>
#define trig_pin 12
#define echo_pin 13
#define buzz_pin 14

void setup() {
  Serial.begin(115200);
  pinMode(trig_pin, OUTPUT);
  pinMode(echo_pin, INPUT);
  pinMode(buzz_pin, OUTPUT);
}

void loop() {
  digitalWrite(trig_pin, LOW);
  delayMicroseconds(3);
  digitalWrite(trig_pin, HIGH);
  delayMicroseconds(12);
  digitalWrite(trig_pin, LOW);

long duration = pulseIn(echo_pin, HIGH);
long distance = duration * 0.034 / 2;

Serial.print("Distance: ");
Serial.print(distance);
Serial.println("cm");

if (distance<75){
  tone(buzz_pin, 1000);
  delay(1000);
}else{
  noTone(buzz_pin);
  delay(1000);
}
delay(1000);

}