int Mode;
 void setup()
 {
  Serial.begin (115200);
  pinMode (13,OUTPUT);
 }

 void loop() 
 {
  int n = Serial.available();
  if (n > 0)
  {
    byte C = Serial.read();
    Serial.write(C);
    if (C == '1')
    digitalWrite (13,1);
    if (C == '0')
    digitalWrite (13,0);

    Mode = C;
  }
  if (Mode == '2')
  {
  digitalWrite(13,1);
  delay(10);
  digitalWrite(13,0);
  delay(10);
  }
  if (Mode == '3')
  {
  digitalWrite(13,1);
  delay(1);
  digitalWrite(13,0);
  delay(10);
  }
  if (Mode == '4')
  {
  digitalWrite(13,1);
  delay(5);
  digitalWrite(13,0);
  delay(5);
  }
  delay(1);
 }