// Pin definitions
const int digitalLedPin = 2;   // Digital LED
const int analogLedPin = 3;    // LED controlled by potentiometer
const int pwmLedPin = 9;       // PWM LED

const int potPin = A0;         // Potentiometer

void setup() {
  pinMode(digitalLedPin, OUTPUT);
  pinMode(analogLedPin, OUTPUT);
  pinMode(pwmLedPin, OUTPUT);
}

void loop() {
  // 1. Digital LED: blink every 1 second
  digitalWrite(digitalLedPin, HIGH);
  delay(500);
  digitalWrite(digitalLedPin, LOW);
  delay(500);

  // 2. Analog LED: brightness controlled by potentiometer
  int potValue = analogRead(potPin);                  // 0-1023
  int analogBrightness = map(potValue, 0, 1023, 0, 255);  
  analogWrite(analogLedPin, analogBrightness);       

  // 3. PWM LED: fixed brightness (example 128 out of 255)
  analogWrite(pwmLedPin, 128);                       

  delay(50); // small delay
}