hi frndz

I need circuit diagram of
4 BIT DIGITAL LOCK
My req is 1st of all we set a master reset pasword
and thn set a user pasword
when my user enter pasword if pasword is currect then my green lines will switch on else red LED remains on
if user can forget there pasword then it can be reset my using my reset password

 

Try an internet search on "digital comparator."