int number = 0;
int oldval = 0;
void setup(){
   Serial.begin(9600);
   pinMode(10, OUTPUT);
   pinMode(13, OUTPUT);
   analogWrite(10, 255);
   delay(500);
   analogWrite(10, 0);
   startBlink();
}

void loop() {
  // send data only when you receive data:
  if (Serial.available() > 0) {
	// read the incoming byte:
	number = Serial.read();
  }

  // say what you got:
  if (oldval != number){
        oldval = number;
	analogWrite(10, number);
        Serial.print(number, BYTE);
  }
}

void startBlink(){                      
  pinMode(13, OUTPUT);                  
                                        
  for (int i=0; i<3; i++){
    digitalWrite(13, HIGH);
    delay(200);
    digitalWrite(13, LOW);
    delay(200);
  }
}