13-01-2011, 01:33 PM
Combination Lock with LCD and Keypad using pic16f628A:
A Brief Description:
This project is written in C language. The basic user lock is of 2 Digits.
The input is taken from a 4x3 Keypad (please see the schematic for more information) and Display the user input on a 2x16 LCD. A pin is assigned as output for activating and deactivating the lock. For demonstration I have connected an LED to that pin.
How combination lock works:
1. Turn switch on (5V DC voltage power supply)
2. A message name “Combination Lock” will display on LCD at first row,
3. Second row display “Enter Pass:” it asked you to enter password for open doors.
4. In this lock design it has three doors. These are the code locks to open doors “door1=05, door2=28, door3=82, door1 & door2 = 33”.
5. If you entered one of the codes in step 4 then press enter key that door will open. For example, you enter 05 for door 1 it’s then open and close door 1 after 5 seconds.
6. If codes you entered are not matched one of the code in step 4 then led door is not turn on.
7. If your first attempt failed the message “invalid code’ display on screen.
8. Then you pressed any key to clear and you can try for second attempt.
After you have reached three attempts but you have not entered correct password. Next Any Keys press alarm will activate for 5 seconds.
Using the Keypad:
Keypad has 12 keys (4x3) starting from 1,2,3,4,5,6,7,8,9,*,0,# (please see the schematic for layout). Numeric keys are used for entering numbers. '*' is used as the Cancel key and '#' is used as the Enter key.
