LED brightness control

Using Arduino Programming Questions
6

Here's my try:

Connect a SPST N.O. momentary from pin 8 to GND with no resistor.
Connect an LED from pin 9 to an LED in series with a current-limiting resistor (220 to 330 ohm) to GND.

My code:

int but = 8;
int led = 9;
int val = 0;

void setup()
{
  pinMode(but, INPUT_PULLUP);
  pinMode(led, OUTPUT);             // not needed, but I like to be explicit
}

void loop()
{
  if(digitalRead(but) == LOW)
  {
    //here: the button is pushed
     val += 20;                                 // increment the brightness of the LED by 1/24th
    val = min(val, 255);                     // maximum PWM value is 255
  }
  else
  {
    //here: the button has been released
    val = 0;                                  // turn the LED OFF
  }

  analogWrite(led,val);                 // adjust the PWM
  delay( 250 );                           // give yourself a chance to see the result
}

should take about 3 seconds from OFF to full brightness. If you need it to be quicker, adjust the delay time
the delay also tends to debounce the switch too