const int ledPin = 13; 
const int potentiometerPin = A0;  

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

void loop() {
      int potentiometerValue = analogRead(potentiometerPin);   int ledBrightness = map(potentiometerValue, 0, 1023, 0, 255);  
        analogWrite(ledPin, ledBrightness);  
          delay(100); 
          }