int ledPin = 8;
int potentiometerPin = A0;

void setup() {
  // put your setup code here, to run once:
pinMode(ledPin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
int potValue = potentiometerValue();
int fadeValue = map (potValue, 0, 1023, 0, 255);

analogWrite(ledPin, fadeValue);
delay(30);
}

int potentiometerValue ()
{
  int val = analogRead(potentiometerPin);
  return val;
}