Abstract:
Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. An access control system forms a vital link in a security chain.
The microcontroller based digital code lock is an access control system that allows only authorized persons to access a restricted area. The electronic control assembly allows the system to unlock the device with a password.
The system is fully controlled by the 8 bit microcontroller ATmega328P which has 32 Kbytes of flash memory where the program is stored and 2Kbytes of RAM. A four digit password needs to be specified by the user. Push button switches and a 16x2 LCD have been used here to set the password which is stored in the RAM.
While unlocking, if the entered password matches with the stored password, then the lock opens and a message is displayed on LCD. Also an output pin is made high and the LED connected to it glows. This lock output pin can be used for further purposes. If the entered password is wrong an Alarm is switched ON.
