8051 LED.asm

      ; put data in RAM  
MOV 30H, #'0'	
MOV 31H, #'1'	
MOV 33H, #'2'	
MOV 34H, #'3'	
MOV 35H, #'4'	
MOV 36H, #'5'	
MOV 37H, #'6'	
MOV 38H, #'7'	
MOV 39H, #'8'	
MOV 39H, #'9'
MOV 41H, #30H  ; Valor no display 1 
MOV 42H, #30H  ; Valor no display 2
MOV 43H, #58   ; dois pontos
MOV 44H, #30H  ; Valor no display 3
MOV 45H, #30H  ; Valor no display 4
		
		; initialise the display
		; see instruction set for details	
CLR P1.3	; clear RS - indicates that instructions are being sent to the module

; function set		
CLR P1.7		; |	
CLR P1.6		; |	
SETB P1.5		; |	
CLR P1.4		; | high nibble set	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E	
CALL delay		; wait for BF to clear					
; function set sent for first time - tells module to go into 4-bit mode
; Why is function set high nibble sent twice? See 4-bit operation on pages 39 and 42 of HD44780.pdf.	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E				
; same function set high nibble sent a second time	
SETB P1.7		; low nibble set (only P1.7 needed to be changed)	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E				
; function set low nibble sent	
CALL delay		; wait for BF to clear

; entry mode set; set to increment with no shift	
CLR P1.7		; |	
CLR P1.6		; |	
CLR P1.5		; |	
CLR P1.4		; | high nibble set	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E	

CLR P1.7		; |	
SETB P1.6		; |	

SETB P1.2		; |	
CLR P1.2		; | negative edge on E	
CALL delay		; wait for BF to clear
; display on/off control
; the display is turned on, the cursor is turned on and blinking is turned on	
CLR P1.7		; |	
CLR P1.6		; |	
CLR P1.5		; |	
CLR P1.4		; | high nibble set	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E	
SETB P1.7		; |	
SETB P1.6		; |	
SETB P1.5		; |	
SETB P1.4		; | low nibble set	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E	
CALL delay		; wait for BF to clear


;loop:
;mov A, #'A'
;lcall sendData
;LCALL voltaUm
;ljmp loop


; send data	
SETB P1.3		; clear RS - indicates that data is being sent to module	

iniciaDisplay:
MOV R1, #41H
LCALL migraValor
LCALL sendData
LCALL voltaUm
MOV R1, #42H
LCALL migraValor
LCALL sendData
LCALL voltaUm
MOV R1, #43H
LCALL migraValor
LCALL sendData
LCALL voltaUm
MOV R1, #44H
LCALL migraValor
LCALL sendData
LCALL voltaUm
MOV R1, #45H
LCALL migraValor
LCALL sendData

MOV R1, #45H ;display 4
LCALL diplayQuatro

migraValor:
MOV A, @R1
MOV R1, A
MOV A, @R1
RET


vaiUm:
MOV A, #10H;
LCALL sendInst
RET

voltaUm:
MOV A, #14H;
LCALL sendInst
RET

diplayQuatro:
LCALL voltaUm
MOV A, @R1		; move data pointed to by R1 to A	
	;JZ finish
	LCALL sendData	; send data in A to LCD module	
	INC R1			; point to next piece of data	
JMP diplayQuatro

MOV R1, #30H		; data to be sent to LCD is stored in 8051 RAM, starting at location 30H

;loop:	
;	MOV A, @R1		; move data pointed to by R1 to A	
;	JZ finish		; if A is 0, then end of data has been reached - jump out of loop	
;	CALL sendCharacter	; send data in A to LCD module	
;	INC R1			; point to next piece of data	
;JMP loop		; repeat

finish:	
JMP $

sendData:
SETB P1.3
LCALL send
RET

sendInst:
CLR P1.3
LCALL send
RET

send:	
MOV C, ACC.7		; |	
MOV P1.7, C		; |	
MOV C, ACC.6		; |	
MOV P1.6, C		; |	
MOV C, ACC.5		; |	
MOV P1.5, C		; |	
MOV C, ACC.4		; |	
MOV P1.4, C		; | high nibble set	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E	
MOV C, ACC.3		; |	
MOV P1.7, C		; |	
MOV C, ACC.2		; |	
MOV P1.6, C		; |	
MOV C, ACC.1		; |	
MOV P1.5, C		; |	
MOV C, ACC.0		; |	
MOV P1.4, C		; | low nibble set	
SETB P1.2		; |	
CLR P1.2		; | negative edge on E	
CALL delay		; wait for BF to clear
RET

delay:	
MOV R0, #50	
DJNZ R0, $	
RET