#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() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(4, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  Serial. begin(115200);
  pinMode(pinbuzzer, OUTPUT);
  myservo.attach(9);
}
  // put your setup code here, to run once:

void loop() {
  float distance = readDistanceCM();
  Serial.print("Measured distance) ");
  Serial.print(readDistanceCM());
  Serial. println(" CM");
  Serial. print("Warning: ");

  if(distance <=200){
    digitalWrite(4, HIGH);
    digitalWrite(7, LOW);
    digitalWrite(8, LOW);
    myservo.write(90);
    delay(15);
    tone(pinbuzzer, 1000);
    delay(200);
    tone(pinbuzzer, 100);
    delay(200);
    Serial.println("STOP");
  }
   else if (distance <=300) {
     noTone(pinbuzzer);
    digitalWrite(4, LOW);
    digitalWrite(7, HIGH);
    delay(1000);
    digitalWrite(7, LOW);
    delay(500);
    digitalWrite(7, LOW);
    digitalWrite(8, LOW);
    Serial.println("HATI--HATI");
  }
  else {
    myservo.write(0);
    noTone(pinbuzzer);
    digitalWrite(4, LOW);
    digitalWrite(7, LOW);
    digitalWrite(8, HIGH);
    Serial.println("SEMOGA SELAMAT SAMPAI TUJUAN");
  }
  // put your main code here, to run repeatedly:
}