Can you give me solution on how to do it, and what coding should i modify?
Sure. It's really simple. Change this:
int incomingByte;
to this:
char incomingByte;
}//no ; here
Fine. So, why is there one here?
};
after the else?
So i need to declare other pin as a output for buzzer?
Yes.
and how do i make the buzer to beep when the RFID tag/card is touch?
The right card or the wrong card?