o sensor de ré para tinkercad

#define buzzer 7

unsigned long echo = 0;
int ultraSoundSignal = 9; //pino do ultrassom
unsigned long ultrasoundValue = 0;
int led[6] = {0, 1, 2, 3, 4, 5};
int freq = 2573;  /* essas frequencias são notas musicais específicas / these frequences are in musical notes*/
int dlay[6] = {100, 150, 200, 250, 300, 350};

void setup()
{
  Serial.begin(9600);
  pinMode(ultraSoundSignal,OUTPUT);
  for(int i = 0; i<6;i++){
    pinMode(led[i], OUTPUT);
}
  pinMode(buzzer, OUTPUT);
}
unsigned long ping()
{
  pinMode(ultraSoundSignal, OUTPUT); // Switch signalpin to output
  digitalWrite(ultraSoundSignal, LOW); // Send low pulse
  delayMicroseconds(2); // Wait for 2 microseconds
  digitalWrite(ultraSoundSignal, HIGH); // Send high pulse
  delayMicroseconds(5); // Wait for 5 microseconds
  digitalWrite(ultraSoundSignal, LOW); // Holdoff
  pinMode(ultraSoundSignal, INPUT); // Switch signalpin to input
  digitalWrite(ultraSoundSignal, HIGH); // Turn on pullup resistor
  // please note that pulseIn has a 1sec timeout, which may
  // not be desirable. Depending on your sensor specs, you
  // can likely bound the time like this -- marcmerlin
  // echo = pulseIn(ultraSoundSignal, HIGH, 38000)
  echo = pulseIn(ultraSoundSignal, HIGH); //Listen for echo
  ultrasoundValue = (echo / 58.138); //convert to CM then to inches
  return ultrasoundValue;
}

void loop()
{
  int x = 0;
  x = ping();
  Serial.println(x);
  delay(250); //delay 1/4 seconds.

  Serial.print("Distancia: ");

  Serial.print(x);
  Serial.print(" cm");
  if(x> 0 && x <= 10){
    ativarLeds(6, 0);
  }
  else if(x > 10 && x <= 20){
    ativarLeds(5, 1);
  }
  else if(x > 20 && x <= 30){
    ativarLeds(4, 2);
  }
  else if(x > 30 && x <= 40){
    ativarLeds(3, 3);
  }
  else if(x > 40 && x <= 50){
    ativarLeds(2, 4);
  }
}
void ativarLeds(int qntdLeds, int f){
  for(int i = 0; i < qntdLeds; i++){
    digitalWrite(led[i], HIGH);
  }
  for(int i = 5; i > qntdLeds - 1; i--){
    digitalWrite(led[i], LOW);
  }
  noTone(buzzer);
  delay(dlay[f]);
  tone(buzzer, freq);
}