const int echopin = 17;
const int trigpin = 5;
const int buzzpin = 4;




void setup() {
  pinMode(buzzpin, OUTPUT);
  pinMode(trigpin, OUTPUT);
  pinMode(echopin, INPUT);
  Serial.begin(115200);
}

void loop() {

 digitalWrite(trigpin, LOW);
 delayMicroseconds(10);
 digitalWrite(trigpin, HIGH);
 delayMicroseconds(10);
 digitalWrite(trigpin, LOW);
 
unsigned long duration = pulseIn(echopin,HIGH);
unsigned int distance = (duration /2)/29.1;

 if(distance <=300){
 
 digitalWrite(buzzpin, HIGH);
 Serial.print(distance);
 Serial.println("");

 }else{
  digitalWrite(buzzpin, LOW);
  Serial.print(distance);
   Serial.println("");
 }
delay(1000);
}