// zero which is front >> one is left >>> two is right
const int TRIG_PIN0    = 10;
const int ECHO_PIN0    = 7;
const int TRIG_PIN1   = 11;
const int ECHO_PIN1   = 6;
const int TRIG_PIN2   = 9;
const int ECHO_PIN2   = 8;
const int BUZZER_PIN  = 2;
int dist_0 = 0 ; // from zero ultera
int dist_1 = 0 ; // from left ultera
int dist_2 = 0 ; // from right ultera
/*
// const int DISTANCE_THRESHOLD = 200; // no usage in this cod 
int activeSensor = 0;

const float SPEED_OF_SOUND = 343.0; // Speed of sound in m/s
// arduino isn't calculator 
float distanceToCm(float duration) {
  // Calculate distance in centimeters
  return (duration * SPEED_OF_SOUND) / 20000.0;
}*/
int readUltrasonicSensor(int trigPin, int echoPin) { // dist is integer and cm unit
  long duration;
  int dist;
  // Trigger ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  //distance = distanceToCm(duration); // remove
  dist=duration/57 ; // 57 is getting this offer for me cm directly 
  return dist;
}
void beep(int times) {
  for (int i = 0; i < times; i++) {
    digitalWrite(BUZZER_PIN, HIGH);
    delay(200);
    digitalWrite(BUZZER_PIN, LOW);
    delay(200);
  }
}

void setup() {
  Serial.begin(9600);
  pinMode(TRIG_PIN0, OUTPUT);
  pinMode(ECHO_PIN0, INPUT);
  pinMode(TRIG_PIN1, OUTPUT);
  pinMode(ECHO_PIN1, INPUT);
  pinMode(TRIG_PIN2, OUTPUT);
  pinMode(ECHO_PIN2, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  // change the name of distance in float func to be dist only 
  // Read ultrasonic sensor 1
  dist_0 = readUltrasonicSensor(TRIG_PIN0, ECHO_PIN0);
  if (dist_0 <= 70 ) { // detect some thing front 
    Serial.print("dist0: ");
    Serial.println(dist_0);
    beep(2);
    // start check other ultera 
  dist_1 = readUltrasonicSensor(TRIG_PIN1, ECHO_PIN1);//left
  dist_2 = readUltrasonicSensor(TRIG_PIN2, ECHO_PIN2);//right
  if ((dist_1 <= 50)&&(dist_2 <= 50 )) {
    //from right and left 
     Serial.println("return back");
          beep(12);

  }
   else if (dist_1 <= 50 ) {
    Serial.print("dist1: ");
    Serial.println(dist_1);
    beep(4);
  }else if (dist_2 <= 50 ) {
    Serial.print("dist2: ");
    Serial.println(dist_2);
    beep(6);
      }
  }
  delay(1000);
}