const byte trig_pin = 12;
const byte echo_pin = 14;
float sound_speed = 0.034;
int buzzerPin = 26;
int buzzer_interval = 0; 
byte led_pins[] = {13, 15, 2, 4, 5, 18, 19, 21, 22, 23};


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(trig_pin , OUTPUT);
  pinMode(echo_pin , INPUT);
  for(int i=0; i<=9; i++){
    pinMode(led_pins[i], OUTPUT);
  }
  indicatorTesting();
  
}

void loop() {
  // put your main code here, to run repeatedly:

int distance = get_distance();
indicator(distance);
  delay(10); // this speeds up the simulation
}

int get_distance(){
  //  getting ready before sending tigger burst
  digitalWrite(trig_pin , LOW);
  delayMicroseconds(2);
 
 //  sending trigger burst
 digitalWrite(trig_pin , HIGH);
 delayMicroseconds(10);
 digitalWrite(trig_pin , LOW);


//  waiting for response : checking HIGH duration of echo pin
 long int duration = pulseIn(echo_pin , HIGH); 
 
 float sound_speed = 0.034;
 long int distance = (duration * sound_speed) / 2;

 return distance;
 
}
void indicatorTesting(){
  for(int i=0;i<=9; i++){
    digitalWrite(led_pins[i], HIGH);
    delay(70);
  }
  for(int i=9;i>=0; i--){
    digitalWrite(led_pins[i], LOW);
    delay(70);
  }
}
void indicator(int distance){
  if(distance<=150 & distance>135){
    led_on(1);
  }
  else if(distance<=135 & distance>120){
    led_on(2);
  }
  else if(distance<=120 & distance>105){
    led_on(3);
  }
  else if(distance<=105 & distance>90){
    led_on(4);
  }
  else if(distance<=90 & distance>75){
    led_on(5);
  }
  else if(distance<=75 & distance>60){
    led_on(6);
  }
  else if(distance<=60 & distance>45){
    led_on(7);
  }
  else if(distance<=45 & distance>30){
    led_on(8);
  }
  else if(distance<=13 & distance>15){
    led_on(9);
  }
  else if(distance<=15 & distance>0){
    led_on(10);
  }
  else{
    led_on(0);
  }
  if(distance<=150){
    buzzer_interval=map(distance,0,150,0,1000);
    buzzer();
    delay(buzzer_interval);
  }

  }
  void led_on(byte led_count){
    //total led which are going to be on 
    for (int i = 0; i < led_count; i++)
    { digitalWrite(led_pins[i] , HIGH); } 
    // total leds which are going to be off 
    for (int i = led_count; i < sizeof(led_pins); i++)
    { digitalWrite(led_pins[i] , LOW); }
    }
  void buzzer(){
    for (int j = 0; j < 3; j++) {
      digitalWrite(buzzerPin, HIGH);
      delay(2);
      digitalWrite(buzzerPin, LOW);
      delay(2); 
      } 
    }