Ultrasonic II




int trig= 7;
int echo= 6;
int led= 13;

void setup() {
  // initialize serial communication:
  Serial.begin(9600);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(led, OUTPUT);
}

void loop()
{
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  long val= pulseIn(echo, HIGH) * 17 / 100;
  Serial.println(val);

  if(val < 50) {
    //5cm 범위 안에들어오면 LED  점등
    digitalWrite(led, HIGH);
  } else {
    digitalWrite(led, LOW);
  }

  delay(100);
}