problem is at interfacing the finger print board with 89s52 .
i m generating the same command via serial communication but the response command , generated by fingerprint board is "invalid command" .
so kindly help me out...
I would suggest you to try to interface 89S52 with PC (via RS232 converter) just to be sure you are sending with the right baudrate and parity. Use win terminal or similar software to check characters you are sending. Write a simple application that sends characters (strings) to serial port.