const int potPin = A0;     // Potentiometer input
const int ledPin = 9;      // PWM output pin

void setup() {
  pinMode(ledPin, OUTPUT);
}

void loop() {
  int potValue = analogRead(potPin);               // Range: 0–1023
  int brightness = map(potValue, 0, 1023, 0, 255); // Scale to PWM range
  analogWrite(ledPin, brightness);                 // Set LED brightness
  delay(10);                                       // Smooth update
}