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(100);
    digitalWrite(13,0);
    delay(100);
  }
if(Mode == '3')
{
digitalWrite(13,1);
    delay(1);
    digitalWrite(13,0);
    delay(10);
}
  delay(100);
}