#define LED 9
int i;

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


void loop() 
  // put your main code here, to run repeatedly:
{
  for(i=0; i<=255; i+=25);
  {
    analogWrite(LED, i);
delay(1000);
}
for(i=255; i>=0; i-=51)
{
   analogWrite(LED, i);
delay(1000);
}

}