void setup() {
   Serial.begin(9600);

   // set volume
   Serial.write(0x7E); 
   Serial.write(0x03); 
   Serial.write(0xA7);
   Serial.write(0x1C); //29 dari 31
   Serial.write(0x7E);
   
   // start sound
   Serial.write(0x7E); 
   Serial.write(0x04); 
   Serial.write(0xA0);
   Serial.write((byte)0x00);
   Serial.write(0x03); // nomor lagu
   Serial.write(0x7E);
   delay(3000);
}

void loop() {
}