Arduino ultrasonic

gistfile1.ino

#include <Ultrasonic.h>
#define echoPin 13
#define triPin 12
#define ledPin 9

Ultrasonic ultrasonic(12,13);

void setup()
{
  Serial.begin(9000);
  pinMode(echoPin, INPUT);
  pinMode(triPin, OUTPUT);
}

void loop()
{
  digitalWrite(ledPin, LOW);
  int val = method_distancia();
  if(val <= 15)
  {
    digitalWrite(ledPin, HIGH);
    delay(100);
  }
  delay(500);
}

int method_distancia()
{
  int distancia = (ultrasonic.Ranging(CM));
  digitalWrite(triPin, LOW);
  delayMicroseconds(2);
  
  digitalWrite(triPin, HIGH);
  delayMicroseconds(10);
  
  digitalWrite(triPin, LOW);
  Serial.print("Distância em CM: ");
  Serial.println(distancia);
  return distancia;
}