[아두이노, 상상을 현실로 만드는 프로젝트 입문편] 코드 10 - 1

ch10_1.ino

void setup() {
  pinMode(2, OUTPUT);
  pinMode(3, INPUT);
}

void loop() {
  analogWrite(11, 0);
  analogWrite(10, 0);
  analogWrite(9, 0);

  digitalWrite(2, HIGH);
  delayMicroseconds(10);
  digitalWrite(2, LOW);

  long duration = pulseIn(3, HIGH);

  if (duration == 0) {
    return;
  }

  long distance = duration / 58.2;

  if (distance < 10) {
    analogWrite(11, 255);
  } else if (distance < 20) {
    analogWrite(10, 255);
  } else if (distance < 30) {
    analogWrite(9, 255);
  }
  
  delay(100);
}