#define trig 3
#define echo 2
void setup() {
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);

  Serial.begin(9600);
}

void loop() {
  float distancia = calcularDistancia();
  Serial.println(distancia);
  delay(500);
}

float calcularDistancia(){
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  long duration = pulseIn(echo, HIGH);
  float distance = duration * 0.034 / 2;
  delay(500);
  return distance;
}