LIST

	NOLIST

;En deze commando`s kun je gebruiken:

;LCD_CLEAR
;LCD_CURSOR_HOME
;LCD_CURSOR_LEFT
;LCD_CURSOR_RIGHT
;LCD_MOVE_ALL_L
;LCD_MOVE_ALL_RIGHT
;LCD_LINE1
;LCD_LINE2
;LCD_DELAY
;LCD_SCROLL_L
;LCD_SCROLL_R
;LCD_INIT
;LCD_CURSOR_OFF
;LCD_CHAR







; LCD control lines
	#define	LCD_RS	0 		; 0 = Command, 1 = Data
	#define LCD_RW	1 		; 0 = Write, 1 = Read
	#define LCD_E	2 		; 1 to send data
	#define LCD_D4	3 		; 4 data lines
	#define LCD_D5	4 
	#define LCD_D6	5 
	#define LCD_D7	6 
	
; Registers we will be using
	#define R_DEL1			0x20	; Delay register
	#define R_DEL2			0x21	; Delay register
	#define R_WDATA_TMP1	0x22
	#define R_WDATA_TMP2	0x23
	#define R_SEND_W_TMP	0x24
	#define	R_WTMP			0x27	; W storage
	#define	R_STMP			0x28	; STATUS storage
	#define	R_STMP1			0x2E	; Send temp register
	#define R_PSEC			0x2F

	CBLOCK	20H
	D1
	D2
	SCROL1
	SCROL2
	ENDC

	;org	00H
	

	;START

LCD_INIT	MACRO	
			CALL	INIT
			LCD_CLEAR
			ENDM

LCD_CHAR	MACRO	CHAR
			MOVLW	CHAR
			CALL	send_w
			ENDM


LCD_CLEAR	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00000001'		; CLEAR LCD
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_CURSOR_HOME	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00000010'		; CURSOR HOME
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_CURSOR_LEFT	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00000100'		; MOVE THE CURSOR TO THE LEFT
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_CURSOR_RIGHT	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00000110'		; MOVE THE CURSOR TO THE RIGHT
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_MOVE_ALL_L	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00011000'		; MOVE TEXT TO LEFT
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_MOVE_ALL_R	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00011100'		; MOVE TEXT TO RIGHT
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_LINE1	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'10000000'		; LINE 1
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_LINE2	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'11000000'		; LINE2
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM


LCD_CURSOR_OFF	MACRO
	bcf		LCD_PORT, LCD_RS	; Command mode
	movlw	b'00001100'		; DISPLAY ON, CURSOR & BLINK OFF
	call	send_w
	bsf		LCD_PORT, LCD_RS	; Data mode
	call	delay_1ms		; Takes a couple of ms
	ENDM

LCD_DELAY	MACRO
		CALL	LCD_DELAY1
		ENDM

LCD_SCROLL_R	MACRO
		CALL	LCD_SCROLL_R1
		ENDM

LCD_SCROLL_L	MACRO
		CALL	LCD_SCROLL_L1
		ENDM


	org 4
	movwf	R_WTMP		; Save W & STATUS
	swapf	STATUS, W
	movwf	R_STMP
	bcf		STATUS, RP0
	
int_cleanup:
	movlw	b'11111000'	; Clear interrupt bits
	andwf	INTCON, F
	swapf	R_STMP, W	; Restore W & STATUS
	movwf	STATUS
	swapf	R_WTMP, F
	swapf	R_WTMP, W
	retfie

; Init sets all I/O lines as outputs and selects PORTA as
; I/O lines by turning the comparators off.
INIT
	clrf	LCD_PORT
	movlw	0x07
	bsf		STATUS, RP0	; Select bank 1
	movlw	b'00000000'	; Select PORTB as outputs
	movwf	LCD_TRIS
	bcf		STATUS, RP0	; Select bank 0

	; Begin the LCD initialisation
	; Power up timer should give delay, but do it anyway
	movlw	0x14
	call	delay
	
	; Send the command to select 4-bit mode first
	bcf		LCD_PORT, LCD_RS
	bcf		LCD_PORT, LCD_RW
	movlw	0x02			; Still in 8-bit, so appears as 0x20 to LCD
	call	w_to_data
	call	pulse_e

; Should now be in 4-bit mode - send init
	movlw	b'00101000'
	call	send_w
	
	movlw	b'00001110'
	call	send_w
	
	movlw	b'00000110'
	call	send_w
	
; ----------------------

send_w
	movwf	R_SEND_W_TMP
	swapf	R_SEND_W_TMP, F
	movlw	0x0F
	andwf	R_SEND_W_TMP, W
	call	w_to_data
	call	pulse_e
	
	swapf	R_SEND_W_TMP, F
	movlw	0x0F
	andwf	R_SEND_W_TMP, W
	call	w_to_data
	call	pulse_e
	RETURN

w_to_data
	movwf	R_WDATA_TMP1
	movf	LCD_PORT, W
	movwf	R_WDATA_TMP2
	bcf		R_WDATA_TMP2, LCD_D4
	bcf		R_WDATA_TMP2, LCD_D5
	bcf		R_WDATA_TMP2, LCD_D6
	bcf		R_WDATA_TMP2, LCD_D7
	btfsc	R_WDATA_TMP1, 0
		bsf		R_WDATA_TMP2, LCD_D4
	btfsc	R_WDATA_TMP1, 1
		bsf		R_WDATA_TMP2, LCD_D5
	btfsc	R_WDATA_TMP1, 2
		bsf		R_WDATA_TMP2, LCD_D6
	btfsc	R_WDATA_TMP1, 3
		bsf		R_WDATA_TMP2, LCD_D7
	movf	R_WDATA_TMP2, W
	movwf	LCD_PORT
	
	return
	
pulse_e
	bsf		LCD_PORT, LCD_E
	nop
	nop
	nop
	nop
	bcf		LCD_PORT, LCD_E
	call	delay_1ms
	call	delay_1ms
	return

; Calls the delay_1ms routine the number of times specified by
; the W register.
delay
	movwf	R_DEL2
delay_loop
	call	delay_1ms
	decfsz	R_DEL2, F
		goto	delay_loop
	return
	
; When called gives a delay of about 1000 cycles, or 1ms at 4Mhz
; before the next instruction is executed.
delay_1ms
	movlw	d'248'
	movwf	R_DEL1
delay_1ms_loop
	nop
	decfsz	R_DEL1, F
		goto	delay_1ms_loop
	return


LCD_DELAY1	
		MOVLW	D'255'
		MOVWF	D2
LUS1	MOVLW	D'255'
		MOVWF	D1
LUS		DECFSZ	D1,F
		GOTO 	LUS
		DECFSZ	D2,F
		GOTO	LUS1
		RETURN

LCD_SCROLL_R1	
		MOVLW	D'16'
		MOVWF	SCROL2
LOOP1	LCD_MOVE_ALL_R
		LCD_DELAY
		DECFSZ	SCROL2,F
		GOTO	LOOP1		
		RETURN

LCD_SCROLL_L1	
		MOVLW	D'16'
		MOVWF	SCROL1
LOOP2	LCD_MOVE_ALL_L
		LCD_DELAY
		DECFSZ	SCROL1,F
		GOTO	LOOP2		
		RETURN

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