Arduino BT and avrdude "not in sync" errors

[ironheartbj18]

i followed everything what they said check out the website here is

Experiencia Arduino + Bluetooth + Android - parte 2/3

( i am not sure if they speak Spanish language since i am proud to be Deaf)

my Android were working connected to Bluetooth. i can see the red blink on Bluetooth serial module. it s working but

why did i get this on my Arduino by said "avrdude: stk500_getsync(): not in sync: resp=0x00" any body knowledge about this to solution the problem?

even i try baud serial.begin(57600) and (115200) it still not get in sync.

void setup()
{
  pinMode(13,OUTPUT);
  pinMode(12,OUTPUT);
  pinMode(11,OUTPUT);
 Serial.begin(115200);
}
 void loop ()
 {
   char c = Serial.read();
   if (c == '1') digitalWrite(13,HIGH);
   if (c == '2') digitalWrite(12,HIGH);
   if (c == '3') digitalWrite(11,HIGH);
   if (c == 'A') digitalWrite(13,LOW);
   if (c == 'B') digitalWrite(13,LOW);
   if (c == 'C') digitalWrite(13,LOW);
   delay(1000);
 }

[ironheartbj18]

why did i get this on my Arduino UNO