int LedPin = 9;
int tmp=255;

void setup() {
  pinMode(LedPin, OUTPUT);
  Serial.begin(9600);
}
void loop() {
  do{
  analogWrite(LedPin,tmp); 
  Serial.println(tmp);
  tmp--;
  }
  while(tmp>=0);

  delay(1500);
  tmp=0;
  do{
  analogWrite(LedPin,tmp); 
  Serial.println(tmp);
  tmp++;
  }
  while(tmp<=255);
  delay(1500);
}