// Simple PWM dimmer: POT on A0, LED on D3 (PWM)
const int POT = A0;
const int LED = 3;

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

void loop() {
  int raw = analogRead(POT);   // 0..1023
  int pwm = raw >> 2;          // 0..255 (fast divide by 4)
  analogWrite(LED, pwm);       // set brightness
  delay(2);                    // tiny settle
}