SerialSoftware fake answer to make it stand-alone - Grove mp3 Serial

Hi!

I’m working on a mp3 player project, with Uno and Grove mp3 Serial.
The Grove mp3 communicates with SerialSoftware, so it wait for an answer to start. I have to open the monitor on the arduino software to make it start playing.
I want to make it a stand-alone piece, with a 12vdc power supply. But when I switch the power on, it still wait for an answer to start.

Is it possible to fake the answer with some code?

I’ve realised when I link the Reset and Ground, or “un-link” it with power on, the mp3 thing respond and start playing.

Would it be possible to program a reset with some code? Or just sending a pulse on a pin linked to the reset?
Or if you would have any other solution…

Here’s the code I’m using:

#include <SoftwareSerial.h>
SoftwareSerial mp3 ( 11, 10); //modify this with the connector you are using.

void setup()
{
	mp3.begin(9600);
	Serial.begin(9600); 
	delay(100);
        if (true ==SetPlayMode(0x01))
        Serial.println("Set The Play Mode to 0x01, Single Loop Mode.");
        else
        Serial.println("Playmode Set Error");
        //PauseOnOffCurrentMusic();
       
}

void loop()
{
SetPlayMode(0x01);
delay(1000);
SetMusicPlay(00,01);
delay(1000);
SetVolume(0x1E);
while(1);
}

//Set the music index to play, the index is decided by the input sequence
//of the music;
//hbyte: the high byte of the index;
//lbyte: the low byte of the index;
boolean SetMusicPlay(uint8_t hbyte,uint8_t lbyte)
{
	mp3.write(0x7E);
	mp3.write(0x04);
	mp3.write(0xA0);
	mp3.write(hbyte);
	mp3.write(lbyte);
	mp3.write(0x7E);
        delay(10);
	 while(mp3.available())
	{
	if (0xA0==mp3.read())
	return true;
	else 
	return false;
        }
}
/* Pause on/off  the current music
boolean PauseOnOffCurrentMusic(void)
{
 mp3.write(0x7E);
 mp3.write(0x02);
 mp3.write(0xA3);
 mp3.write(0x7E);
 delay(10);
 while(mp3.available())
 {
 if (0xA3==mp3.read())
 return true;
 else 
 return false;
 }
}*/



//Set the volume, the range is 0x00 to 0x1F
boolean SetVolume(uint8_t volume)
{
 mp3.write(0x7E);
 mp3.write(0x03);
 mp3.write(0xA7);
 mp3.write(volume);
 mp3.write(0x7E);
 delay(10);
 while(mp3.available())
 {
 if (0xA7==mp3.read())
 return true;
 else 
 return false;
 }
}



boolean SetPlayMode(uint8_t playmode)
{
  if (((playmode==0x00)|(playmode==0x01)|(playmode==0x02)|(playmode==0x03))==false)
  {
    Serial.println("PlayMode Parameter Error! ");
    return false;
  }
   mp3.write(0x7E);
 mp3.write(0x03);
 mp3.write(0xA9);
 mp3.write(playmode);
 mp3.write(0x7E);
 delay(10);
 while(mp3.available())
 {
 if (0xA9==mp3.read())
 return true;
 else 
 return false;
 }

}

Thanks!