Digital code lock with already defined password:
Password is: 465
/************************************************************************************/
// PROGRAM TO DEMONSTRATE INTERFACING OF HEX DISPALY WITH MCS51
/************************************************************************************/
ORG 0000H
/************************************************************************************/
/* I/O PIN INITIALISATIONS AND DECLARATIONS */
/************************************************************************************/
C1 EQU P2.0
C2 EQU P2.1
C3 EQU P2.2
C4 EQU P2.3
ROW1 EQU P2.4
ROW2 EQU P2.5
ROW3 EQU P2.6
ROW4 EQU P2.7
RS equ p3.0
RW equ p3.1
EN equ p3.2
LCD equ p1
MOV R1,#'4'
MOV R2,#'6'
MOV R3,#'5'
MOV P2,#00H
MOV P0,#00H
MOV B,#00H
MOV R3,#00H
AGAIN: MOV LCD,#38H
ACALL CMD
ACALL DELAY
MOV LCD,#01H
ACALL CMD
ACALL DELAY
MOV LCD,#0EH
ACALL CMD
ACALL DELAY
MOV LCD,#06H
ACALL CMD
ACALL DELAY
MOV LCD,#80H
ACALL CMD
ACALL DELAY
MOV DPTR,#200H
MOV LCD,#01H
ACALL CMD
ACALL DELAY
MOV LCD,#80H
ACALL CMD
ACALL DELAY
ABC1: CLR A
MOVC A,@A+DPTR
JZ GO1
MOV LCD,A
LCALL DISP
INC DPTR
MOV LCD,#06H
ACALL CMD
ACALL DELAY
SJMP ABC1
GO1: MOV LCD,#0C5H
ACALL CMD
ACALL DELAY
CLR A
ACALL KEYBOARD
MOV R7,A
CLR A
ACALL KEYBOARD
MOV R0,A
CLR A
ACALL KEYBOARD
MOV R4,A
ACALL DELAY
CLR A
MOV A,R1
CJNE A,07H,DID_NOT
CLR A
MOV A,R2
CJNE A,00H,DID_NOT
CLR A
MOV A,R4
CJNE A,04H,DID_NOT
SETB P3.3
SETB P3.4
CLR P3.5
CLR P3.6
ACALL DELAY
SETB P3.5
SETB P3.6
ACALL DELAY
CLR P3.5
CLR P3.6
MOV DPTR,#250H
MOV LCD,#01H
ACALL CMD
ACALL DELAY
MOV LCD,#80H
ACALL CMD
ACALL DELAY
ABC2: CLR A
MOVC A,@A+DPTR
JZ GO2
MOV LCD,A
LCALL DISP
INC DPTR
MOV LCD,#06H
ACALL CMD
ACALL DELAY
SJMP ABC2
GO2: ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
lJMP AGAIN
DID_NOT: SETB P3.5
SETB P3.6
CLR P3.3
CLR P3.4
ACALL DELAY
SETB P3.3
SETB P3.4
ACALL DELAY
CLR P3.3
CLR P3.4
MOV DPTR,#300H
MOV LCD,#01H
ACALL CMD
ACALL DELAY
MOV LCD,#80H
ACALL CMD
ACALL DELAY
ABC3: CLR A
MOVC A,@A+DPTR
JZ GO3
MOV LCD,A
LCALL DISP
INC DPTR
MOV LCD,#06H
ACALL CMD
ACALL DELAY
SJMP ABC3
GO3: ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
ACALL DELAY
LJMP AGAIN
/************************************************************************************/
/* READING COLUMN VALUE */
/************************************************************************************/
KEYBOARD: ACALL DELAY
MOV P2, #0FH
ACALL DELAY
K1: MOV A,P2
CJNE A,#0FH,KK1
SJMP K1
KK1: JB C1,N1
MOV B,#00h
ACALL DELAY
N1: JB C2,N2
MOV B,#01h
ACALL DELAY
N2: JB C3,N3
MOV B,#02h
ACALL DELAY
N3: JB C4,N4
MOV B,#03h
ACALL DELAY
/************************************************************************************/
/* READING ROW VALUE */
/************************************************************************************/
N4: MOV P2, #0F0H
K11: MOV A,P2
CJNE A,#0F0H,KK11
SJMP K11
KK11: ACALL DELAY
JB ROW1,NR1
MOV R3,#00h
ACALL DELAY
NR1: JB ROW2,NR2
MOV R3,#04h
ACALL DELAY
NR2: JB ROW3,NR3
MOV R3,#08h
ACALL DELAY
NR3: JB ROW4,NR4
MOV R3,#0Ch
ACALL DELAY
NR4: MOV A,R3
/************************************************************************************/
/* SENDING KEYVALUE TO PORT 0 AND SERAIL PORT */
/************************************************************************************/
MOV DPTR,#MSG
ADD A,B
MOVC A,@A+DPTR
MOV LCD,A
ACALL DISP
RET
/************************************************************************************/
/* DELAY SUBROUTINE */
/************************************************************************************/
DELAY: MOV R6,#5FH
a1: MOV R5,#0FEH
a2: DJNZ R5,a2
DJNZ R6,a1
RET
CMD: CLR RS
CLR RW
SETB EN
NOP
CLR EN
RET
DISP: SETB RS
CLR RW
SETB EN
NOP
CLR EN
RET
/************************************************************************************/
/* LOOKUP TABLE W.R.T 0-15 SWITCHES IN HEX KEYPAD */
/************************************************************************************/
MSG: DB '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F',0
ORG 200H
DB 'CONFIRM PASSWORD',0
ORG 250H
DB 'PASSWORD MATCHED',0
ORG 300H
DB 'WRONG PASSWORD',0
END
