Hey,
The code posted by you works. Thanks a million for the help.
I was assuming that the default baud must be 9600 which was incorrect.
Also I used blank sketch to pass through the serial commands which did not work...what might be the issue?...because I did not authenticate with password first?
Earlier the connections for Rx and Tx of fingerprint sensor were directly connected to Rx Tx of the board...effectively connecting it to UART of my laptop.