Object-Activated Smart Fan using Arduino and Ultrasonic Sens

const int trigPin = 8;
const int echoPin = 9;
const int in1 = 3;
const int in2 = 4;
const int enA = 5;

int motorSpeed = 220; // Adjust speed here (Max: 255)
long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(enA, OUTPUT);

  Serial.begin(9600);
}

void loop() {
  distance = getDistance();

  if (distance <= 20) {
    digitalWrite(in1, HIGH);
    digitalWrite(in2, LOW);
    analogWrite(enA, motorSpeed);
    Serial.println("Fan: Rotating");
  } else {
    digitalWrite(in1, LOW);
    digitalWrite(in2, LOW);
    analogWrite(enA, 0);
    Serial.println("Fan: Stopped");
  }

  delay(200);
}

int getDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  return duration * 0.034 / 2;
}