// C++ code
//
void setup()
{
 Serial.begin(9600);
  pinMode(7, OUTPUT);
  pinMode(6, INPUT);
  pinMode(9, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(2, OUTPUT);
}

void loop()
{
  digitalWrite(7, LOW);
  delayMicroseconds(2); 
  digitalWrite(7, HIGH);
  delayMicroseconds(10);
  digitalWrite(7, LOW);
  
  long time = pulseIn(6, HIGH);
  float distancia = time * 0.0001 * 340 /2;
  
  if (distancia > 200) {
    digitalWrite(9, HIGH);
    digitalWrite(8, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    digitalWrite(3, LOW);
    digitalWrite(2, LOW);
  }else if(distancia >= 100 && distancia <= 200){
    digitalWrite(5, HIGH);
    digitalWrite(4, HIGH);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    digitalWrite(3, LOW);
    digitalWrite(2, LOW);
    tone(11, 500);
    delay(500);
    noTone(11);
    delay(100);
  }else{
    digitalWrite(3, HIGH);
    digitalWrite(2, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    tone(11, 5000);
    delay(500);
    noTone(11);
    delay(100);
  }
    
  Serial.println(distancia); 
}