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Electronic code lock with user defined password using 8051 microcontroller (AT89C51)
Summary
An electronic lock or digital lock is a device which has an electronic control assembly attached to it. They are provided with an access control system. This system allows the user to unlock the device with a password. The password is entered by making use of a keypad. The user can also set his password to ensure better protection. The major components include akeypad, LCD and the controller AT89C51 which belongs to the 8051 series of microcontrollers. This article describes the making of an electronic code lock using the 8051 microcontroller.
Description
A 4x3 matrix keypad and a 16x2 LCD have been used here. Keypad and LCD are very commonly used input & output devices, respectively. A four digit predefined password needs to be specified the user. This password is stored in the system.
While unlocking, if the entered password from keypad matches with the stored password, then the lock opens and a message is displayed on LCD. Also an output pin is made high to be used for further purpose.
The connections in the circuit are as following: port P2 of microcontroller AT89C51 is used as data input port which is connected to data pins (7-14) of LCD. P1^0, P1^1 and P1^2 pins of microcontroller are connected to control pins RS, RW and EN of LCD. Port P0 is used to take input from keypad. P0^7 has been used as lock output pin of controller. As the program starts, string ‘Enter Password’ is displayed on LCD. The keypad is scanned for pressed digits one by one. Every time, row and column of the key pressed is detected and a ‘*’ is displayed on LCD corresponding to the entered number. After the four digits are entered, the user is prompted to ‘Confirm Password’ and again the input is taken through LCD. If the passwords do not match, a message is displayed to indicate ‘Wrong Password’; otherwise the user is prompted to unlock the device. To unlock, user needs to
Summary
An electronic lock or digital lock is a device which has an electronic control assembly attached to it. They are provided with an access control system. This system allows the user to unlock the device with a password. The password is entered by making use of a keypad. The user can also set his password to ensure better protection. The major components include akeypad, LCD and the controller AT89C51 which belongs to the 8051 series of microcontrollers. This article describes the making of an electronic code lock using the 8051 microcontroller.
Description
A 4x3 matrix keypad and a 16x2 LCD have been used here. Keypad and LCD are very commonly used input & output devices, respectively. A four digit predefined password needs to be specified the user. This password is stored in the system.
While unlocking, if the entered password from keypad matches with the stored password, then the lock opens and a message is displayed on LCD. Also an output pin is made high to be used for further purpose.
The connections in the circuit are as following: port P2 of microcontroller AT89C51 is used as data input port which is connected to data pins (7-14) of LCD. P1^0, P1^1 and P1^2 pins of microcontroller are connected to control pins RS, RW and EN of LCD. Port P0 is used to take input from keypad. P0^7 has been used as lock output pin of controller. As the program starts, string ‘Enter Password’ is displayed on LCD. The keypad is scanned for pressed digits one by one. Every time, row and column of the key pressed is detected and a ‘*’ is displayed on LCD corresponding to the entered number. After the four digits are entered, the user is prompted to ‘Confirm Password’ and again the input is taken through LCD. If the passwords do not match, a message is displayed to indicate ‘Wrong Password’; otherwise the user is prompted to unlock the device. To unlock, user needs to