ÿþ;TESTED 4-BIT LCD CODE FOR 16X2 AND 16X4 DISPLAY (HD44780 COMPATABLE LCD)

;CREATED BY ASIF ALI (DARE DEVIL)

;FEEL FREE TO ASK IF ANY PROBLEM

;EMAIL ID:	sirfrajput@yahoo.com

;EMAIL ID:	sirfrajput@gmail.com

;PIN CONFIGURATION

;P1.7 --------> DB7

;P1.6 --------> DB6

;P1.5 --------> DB5

;P1.4 --------> DB4

;P3.7 --------> EN

;P3.5 --------> RS

;P3.4 --------> RW

;FOR 16X2 DISPLAY ITS READEY TO RUN CODE JUST MAKE HEX AND BURN IT ON MCU

;=========================================================================

;NOTE: FOR 16X4 JUST REMOVE COMMENT SIGN ";" WHERE ITS WRITTEN ";(16X4)"

;=========================================================================

;AND AT END I WOULD LIKE TO THANK ALL OF MEMBERS OF 8052 WHO GAVE ME SUCH

;IMPORTANT KNOWLEDGE ABOUT LCD INTERFACING TO LCD PROGRAMMING.

;SO GUYS JUST BURN THE PROGRAM ON MCU AND HAVE FUN IT WILL BE LOOK LIKE

;=========================================================================

;                            PREVIEW

;     FOR 16X2

;T%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%W%

;Q%   DARE DEVIL   Q%

;Q%    ENGINEER    Q%

;Z%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%]%

;

;T%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%W%

;Q%  M. ASIF ALI   Q%

;Q%    RAJPUT      Q%

;Z%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%]%

;     FOR 16X4

;T%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%W%

;Q%   DARE DEVIL   Q%

;Q%    ENGINEER    Q%

;Q%NOONE IS PERFECTQ%

;Q%  I AM NOBODY   Q%

;Z%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%]%

;T%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%W%

;Q%  M. ASIF ALI   Q%

;Q%    RAJPUT      Q%

;Q%  www.8052.com  Q%

;Q%  I LOVE 8052   Q%

;Z%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%P%]%

;=========================================================================

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

		ORG 0000H

		LJMP MAIN

		ORG 0030H

MAIN:		NOP

 		EN      EQU   P3.7

 		RS      EQU   P3.5

 		RW      EQU   P3.4

		DAT    	EQU   P1

		LCALL LCD_INT

AGAIN:		LCALL CLEAR

		LCALL LINE1

		MOV DPTR,#MYDATA

		LCALL LOOP

		LCALL LINE2

		MOV DPTR,#MYDAT2

		LCALL LOOP

		;LCALL LINE3			;(16X4)

		;MOV DPTR,#MYDAT3		;(16X4)

		;LCALL LOOP			;(16X4)

		;LCALL LINE4			;(16X4)

		;MOV DPTR,#MYDAT4		;(16X4)

		;LCALL LOOP			;(16X4)

;------------------------------------------------------------------------

		LCALL LINE1

		MOV DPTR,#MYDAT5

		LCALL LOOP

		LCALL LINE2

		MOV DPTR,#MYDAT6

		LCALL LOOP

		;LCALL LINE3			;(16X4)

		;MOV DPTR,#MYDAT7		;(16X4)

		;LCALL LOOP			;(16X4)

		;LCALL LINE4			;(16X4)

		;MOV DPTR,#MYDAT8		;(16X4)

		;LCALL LOOP			;(16X4)

		SJMP AGAIN

;=========================================================================

W_NIB:		PUSH  ACC           	;Save A for low nibble

		ORL   DAT,#0F0h    	;Bits 4..7 <- 1

		ORL   A,#0Fh        	;Don't affect bits 0-3

		ANL   DAT,A        	;High nibble to display

		SETB  EN 

		CLR   EN 

		POP   ACC           	;Prepare to send

		SWAP  A             	;...second nibble

		ORL   DAT,#0F0h    	; Bits 4...7 <- 1

		ORL   A,#0Fh       	; Don't affect bits 0...3

		ANL   DAT,A        	;Low nibble to display

		SETB  EN 

		CLR   EN 

		RET

;=========================================================================

LCD_INT:	CLR   RS

 		CLR   RW

 		CLR   EN

 		SETB  EN

 		MOV   DAT,#028h

 		CLR   EN

 		LCALL SDELAY

 		MOV   A,#28h

		LCALL COM

 		MOV   A,#0Ch

		LCALL COM

 		MOV   A,#06h

 		LCALL COM

		LCALL CLEAR

		MOV A,#080H

		LCALL COM

 		RET

;=========================================================================

CLEAR:		CLR   RS

		MOV   A,#01h

 		LCALL COM

		RET



;=========================================================================

DATAW:		SETB  RS

		CLR RW

		LCALL W_NIB

		LCALL LDELAY

		RET

;=========================================================================

SDELAY:       	MOV R6,#1    			

HERE2:          MOV R7,#255  			

HERE:           DJNZ R7,HERE

                DJNZ R6,HERE2

                RET

;=========================================================================

LDELAY:       	MOV R6,#100    			

HER2:          	MOV R7,#255  			

HER:          	DJNZ R7,HER

                DJNZ R6,HER2

                RET

;=========================================================================

COM:		CLR RS

		CLR RW

		LCALL W_NIB

		LCALL SDELAY

		RET

;=========================================================================

LINE1:		MOV A,#002H

		LCALL COM

		RET

LINE2:		MOV A,#0C0H

		LCALL COM

		RET

LINE3:		MOV A,#090H

		LCALL COM

		RET

LINE4:		MOV A,#0D0H

		LCALL COM

		RET

;=========================================================================

LOOP:		CLR A

		MOVC A,@A+DPTR

		JZ GO_B2

		LCALL DATAW

		LCALL SDELAY

		INC DPTR

		SJMP LOOP

GO_B2:		RET

;=========================================================================

MYDATA:		DB "   DARE DEVIL   ",0

MYDAT2:		DB "    ENGINEER    ",0



MYDAT3:		DB "NOONE IS PERFECT",0

MYDAT4: 	DB "  I AM NOBODY   ",0



MYDAT5:		DB "  M. ASIF ALI   ",0

MYDAT6:		DB "    RAJPUT      ",0



MYDAT7: 	DB "  www.8052.com  ",0

MYDAT8: 	DB "  I LOVE 8052   ",0

;=========================================================================

		END