Exercise 2 Solution

int brightness = 0; // this can also be declared inside loop()
int LEDPin = 11;

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

void loop()
{
  // increase gradually
  for (brightness = 0; brightness <= 255; brightness++) {
    analogWrite(LEDPin, brightness);
    delay(10);
  }
  /* brightness++ is equivalent to brightness = brightness+1;
                  is also equivalent to brightness += 1; */
  // decrease gradually
  for (brightness = 255; brightness >= 0; brightness--) {
    analogWrite(LEDPin, brightness);
    delay(10);
  }
}