#define ECHO_PIN 3
#define TRIG_PIN 2
#define pinBuzzer 5
#include <Servo.h>
Servo myservo;

int potpin = 0; 
int val;

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;
}


void setup() {
  // put your setup code here, to run once:
pinMode (TRIG_PIN, OUTPUT);
pinMode (ECHO_PIN, INPUT );
Serial.begin (115200);
pinMode (pinBuzzer, OUTPUT );
myservo.attach (9);
}

void loop() {
  // put your main code here, to run repeatedly:
float distance = readDistanceCM();
Serial.print("Measured distance: ");
Serial.println(readDistanceCM ));

if (distance <= 200){
  myservo.write (90);
  delay (15);
  tone (pinBuzzer,1000);
  delay (200);
  tone (pinBuzzer,500);
  delay (200);
}
else {
  myservo.write (0);
  noTone (pinBuzzer);
}

}