sumant08
Sep 24 2009, 8:28 AM
I want to connect 20x4 lcd to 8051.
I am using the same .asm code which i used for 16x2 lcd.
It is displaying the data but the first line is cont. on the third line & second line on fourth line.
Is initialization code same for both the lcd ?, i.e 38h , 0ch , 01 , 06 , 80h ,0 ...
I am using the same .asm code which i used for 16x2 lcd.
It is displaying the data but the first line is cont. on the third line & second line on fourth line.
Is initialization code same for both the lcd ?, i.e 38h , 0ch , 01 , 06 , 80h ,0 ...
Arun Kumar V
Sep 24 2009, 11:37 AM
It is displaying the data but the first line is cont. on the third line & second line on fourth line.
Yep, the initialization is same as 16X2 LCD, the third line is the continuation of first line and fourth line that of second line.
first line address : 00h to 13h
second line address : 40h to 53h
third line : 14h to 27h
fourth line : 54h to 67h
Arun
sumant08
Sep 24 2009, 1:08 PM
Thanks...
But can u pls post a demo code for displaying data on 4 different lines...
But can u pls post a demo code for displaying data on 4 different lines...
Arun Kumar V
Sep 25 2009, 4:27 AM
O.K sumant, here's the code i wrote for you :
and here is its working :
Arun
CODE:
;***********************************************************************
; 20X4 LCD DEMO CODE FOR 8051,WRITTEN BY ARUN KUMAR V - DATE: 25/09/09
;***********************************************************************
$MOD51
LCD EQU P1
RS EQU P3.2
RW EQU P3.3
EN EQU P3.4
ORG 0000H
MAIN: LCALL PWR_DELAY
LCALL INIT
LINE1: MOV A,#080H
LCALL CMD
MOV DPTR,#MSG_1
AGAIN1: CLR A
MOVC A,@A+DPTR
JZ LINE2
LCALL DAT
INC DPTR
SJMP AGAIN1
LINE2: MOV A,#0C0H
LCALL CMD
MOV DPTR,#MSG_2
AGAIN2: CLR A
MOVC A,@A+DPTR
JZ LINE3
LCALL DAT
INC DPTR
SJMP AGAIN2
LINE3: MOV A,#094H
LCALL CMD
MOV DPTR,#MSG_3
AGAIN3: CLR A
MOVC A,@A+DPTR
JZ LINE4
LCALL DAT
INC DPTR
SJMP AGAIN3
LINE4: MOV A,#0D4H
LCALL CMD
MOV DPTR,#MSG_4
AGAIN4: CLR A
MOVC A,@A+DPTR
JZ DONE
LCALL DAT
INC DPTR
SJMP AGAIN4
DONE: SJMP $
;****************************LCD SUBROUTINES****************************************
DAT: SETB EN ;H->L PULSE ON E
SETB RS ;RS=1 DATA
CLR RW ;RW=0 FOR WRITE
MOV LCD,A ;MOVE ACC.DATA TO PORT
CLR EN
NOP
LCALL DDELAY
RET
;****************************LCD SUBROUTINES****************************************
CMD: SETB EN ;H->L PULSE ON E
CLR RS ;RS=0 FOR COMMAND
CLR RW ;RW=0 FOR WRITE
MOV LCD,A ;MOVE ACC. DATA TO PORT
CLR EN
NOP
LCALL DDELAY
RET
;****************************LCD SUBROUTINES****************************************
INIT: MOV A,#038H ; INITIALIZE, 2-LINES, 5X7 MATRIX.
LCALL CMD
ACALL DDELAY ;INITIAL DELAY 4.1MSEC
MOV A,#038H ; INITIALIZE, 2-LINES, 5X7 MATRIX.
LCALL CMD
ACALL DDELAY ;
MOV A,#038H ; INITIALIZE, 2-LINES, 5X7 MATRIX.
LCALL CMD
MOV A,#0EH ; VISIBLE CURSOR ON;
LCALL CMD
MOV A,#01H ; CLEAR LCD SCREEN
LCALL CMD
MOV A,#06H ; SHIFT CURSOR RIGHT
LCALL CMD
RET
;****************************LCD SUBROUTINES****************************************
CLEAR: MOV A,#01H
LCALL CMD
RET
;****************************LCD SUBROUTINES****************************************
DDELAY: MOV R5,#41D
QT2: MOV R6,#50D
QT1: DJNZ R6,QT1
DJNZ R5,QT2
RET
;****************************LCD SUBROUTINES****************************************
PWR_DELAY:
MOV R4,#30D
H2: MOV R3,#250D
H1: DJNZ R3,H1
DJNZ R4,H2
RET
ORG 250H
MSG_1:
DB "THIS IS LINE1 OF LCD",00H
MSG_2:
DB "THIS IS LINE2 OF LCD",00H
MSG_3:
DB "THIS IS LINE3 OF LCD",00H
MSG_4:
DB "THIS IS LINE4 OF LCD",00H
END
; 20X4 LCD DEMO CODE FOR 8051,WRITTEN BY ARUN KUMAR V - DATE: 25/09/09
;***********************************************************************
$MOD51
LCD EQU P1
RS EQU P3.2
RW EQU P3.3
EN EQU P3.4
ORG 0000H
MAIN: LCALL PWR_DELAY
LCALL INIT
LINE1: MOV A,#080H
LCALL CMD
MOV DPTR,#MSG_1
AGAIN1: CLR A
MOVC A,@A+DPTR
JZ LINE2
LCALL DAT
INC DPTR
SJMP AGAIN1
LINE2: MOV A,#0C0H
LCALL CMD
MOV DPTR,#MSG_2
AGAIN2: CLR A
MOVC A,@A+DPTR
JZ LINE3
LCALL DAT
INC DPTR
SJMP AGAIN2
LINE3: MOV A,#094H
LCALL CMD
MOV DPTR,#MSG_3
AGAIN3: CLR A
MOVC A,@A+DPTR
JZ LINE4
LCALL DAT
INC DPTR
SJMP AGAIN3
LINE4: MOV A,#0D4H
LCALL CMD
MOV DPTR,#MSG_4
AGAIN4: CLR A
MOVC A,@A+DPTR
JZ DONE
LCALL DAT
INC DPTR
SJMP AGAIN4
DONE: SJMP $
;****************************LCD SUBROUTINES****************************************
DAT: SETB EN ;H->L PULSE ON E
SETB RS ;RS=1 DATA
CLR RW ;RW=0 FOR WRITE
MOV LCD,A ;MOVE ACC.DATA TO PORT
CLR EN
NOP
LCALL DDELAY
RET
;****************************LCD SUBROUTINES****************************************
CMD: SETB EN ;H->L PULSE ON E
CLR RS ;RS=0 FOR COMMAND
CLR RW ;RW=0 FOR WRITE
MOV LCD,A ;MOVE ACC. DATA TO PORT
CLR EN
NOP
LCALL DDELAY
RET
;****************************LCD SUBROUTINES****************************************
INIT: MOV A,#038H ; INITIALIZE, 2-LINES, 5X7 MATRIX.
LCALL CMD
ACALL DDELAY ;INITIAL DELAY 4.1MSEC
MOV A,#038H ; INITIALIZE, 2-LINES, 5X7 MATRIX.
LCALL CMD
ACALL DDELAY ;
MOV A,#038H ; INITIALIZE, 2-LINES, 5X7 MATRIX.
LCALL CMD
MOV A,#0EH ; VISIBLE CURSOR ON;
LCALL CMD
MOV A,#01H ; CLEAR LCD SCREEN
LCALL CMD
MOV A,#06H ; SHIFT CURSOR RIGHT
LCALL CMD
RET
;****************************LCD SUBROUTINES****************************************
CLEAR: MOV A,#01H
LCALL CMD
RET
;****************************LCD SUBROUTINES****************************************
DDELAY: MOV R5,#41D
QT2: MOV R6,#50D
QT1: DJNZ R6,QT1
DJNZ R5,QT2
RET
;****************************LCD SUBROUTINES****************************************
PWR_DELAY:
MOV R4,#30D
H2: MOV R3,#250D
H1: DJNZ R3,H1
DJNZ R4,H2
RET
ORG 250H
MSG_1:
DB "THIS IS LINE1 OF LCD",00H
MSG_2:
DB "THIS IS LINE2 OF LCD",00H
MSG_3:
DB "THIS IS LINE3 OF LCD",00H
MSG_4:
DB "THIS IS LINE4 OF LCD",00H
END
and here is its working :
Arun
nischay kumar
Sep 26 2009, 12:07 AM
WOW! Arun, thanks for the code and testing.
Ajay Bhargav
Sep 26 2009, 8:30 AM
[Topic moved to 8051 Discussion forum]
sumant08
Sep 26 2009, 2:24 PM
Thanks....Arun