const int trigger=2;
const int echo=3;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(trigger, OUTPUT);
pinMode(echo, INPUT);
digitalWrite(trigger, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
long t;
long d;
digitalWrite(trigger,HIGH);
delayMicroseconds(10);
digitalWrite(trigger, LOW);
t=pulseIn(echo,HIGH);
d=t/59;
Serial.print("Distancia: ");
Serial.print(d);
Serial.print("cm");
delay(100);
}