8051 Based Security Lock System ( 6 digit password)

Introduction

Security is a prime concern in our day-today life. Everyone wants to be as much secure as possible. The issue of security is very paramount at home doors and safe. An access control for doors forms vital link in a security chain. Therefore we intend to aid in security at home by bringing in a security lock system that involves an individual to enter the password before getting an access to some items, a particular room or building.

Security lock system is basically an electronic lock device. This system allows the user to unlock the device with a 6 digit password. The password is entered by making use of a keypad. The user can also always change his password to ensure better protection. The major components include a keypad, buzzer, I/O board with LCD and LEDs, and the microcontroller P89V51RD2 board which belongs to the 8051 series of microcontrollers. . 

Description

In this system, a 4x3 matrix keypad and a 16x2 LCD have been used here. Keypad and LCD are very commonly used input & output devices, respectively. A 6 digit predefined password is 123456. This password is stored in the system and the user is allowed to change it any time. As the program starts, the menu is displayed on LCD. The contents of the menu are listed as below:

1: UNLOCK      2: BELL      3: Set PIN       4: SETUP

To access it, the user needs to press the key as follow the number specific for each function in the menu.

When the user presses 1, the system will request for enter password to unlock. The keypad is scanned for pressed keys and corresponding digits are identified. The passkey is displayed as ‘******’ on the LCD screen. After the six digits are entered, they are compared with the pre-set password. If all the six digits match with set password, LCD displays ‘Lock Open’, a green led will light on and the buzzer will beep twice. If the password is wrong, ‘Wrong Password’ is sent to be displayed on LCD, a red led will light on and the buzzer will beep once. If more than four attempts are made with wrong password to open the electronic lock, the system will gets locked, all the LEDs will light on and the buzzer is beeps continuously to warning for 1 minutes.

When the user presses 2, the system will functions as a door bell and the purpose is aim for a guest who visit the host . The LCD will display a message ‘WELCOME, PLEASE WAITING FOR RESPONSE’ and the buzzer will beep twice for function as bell.

When the user presses 3, the system will requests for enter password to access the set PIN function.  If the password is match, the system will request for enter new PIN for the system. This PIN will overwrite the preset PIN and store in the system. When successful, the Green LED will blink and buzzer will beep 3 times. Else, the red led will light on and the buzzer will beep once.

When the user presses 4, the system will requests for enter password to access the Setup function. If the password is match, the system is allow user to set the unlock time from 1 second to 9 second. Else, the red led will light on and the buzzer will beep once.

Besides that, there is another hidden function is this Security Lock System. This function is Emergency Alarm. To activate it, user have to press key ‘*’ and follow by ‘#’, otherwise, the alarm will not activated. The purpose of this function is allow user to use the alarm to attract others attention. Once the alarm activated, all the LEDs will continues blinking and the buzzer will give alert for a period.

Once the reset button of the controller board has pressed, all the setting will return to the origin. Hence, the system will run with the preset setting.