; RB4-DB4, RB5-DB5, RB6-DB6, RB7-DB7, RB3-ENABLE, RB0-RS, RA0-RW
;16 MHz


	list p=16F628 ; list directive to define processor
#include p16F628.inc ; processor specific variable definitions

	errorlevel -302 ; suppress message 302 from list file 
	__config _HS_OSC &_CP_OFF &_WDT_OFF &_MCLRE_OFF &_BODEN_OFF &_LVP_OFF

		cblock	0x20		;start of general purpose registers
			count			;used in looping routines
			count1			;used in delay routine
			counta			;used in delay routine
			countb			;used in delay routine
			templcd			;temp store for 4 bit mode
			templcd2
			dataL
			endc

SW_PORT		Equ	PORTA
LCD_TRIS	Equ	TRISB
LCD_PORT	Equ	PORTB
LCD_RS		Equ	0x00			;LCD handshake lines
LCD_E		Equ	0x03
SW1			Equ	0x02
LCD_RW		Equ	0x00

		org	0x0000

		movlw	0x07
		movwf	CMCON			;turn comparators off (make it like a 16F84)

Initialise	
		clrf	PORTA
		clrf	PORTB
		clrf	count



SetPorts

		bsf 	STATUS,	RP0			;select bank 1
		movlw	b'00000110'		;make outputs, and RX TX input
		movwf	TRISB
		movlw 	b'11111110'
		movwf	PORTA			;make inputs, and RW output

		movlw 	.51           		 ; .51=4800 bps (0, 0x19 - 9600 x0C=19200 bps)
        movwf 	SPBRG

		movlw	b'00100000'
		movwf	TXSTA
	
        bcf STATUS,RP0        		; RAM PAGE 0

        movlw 	b'10010000'    	   ; enable Async Reception
        movwf 	RCSTA 
	   

		

		;bsf		PIE1,	RCIE
		;bsf		INTCON,PEIE
		;bsf		INTCON, GIE
		call	Delay50



		movf 	RCREG,W
        movf 	RCREG,W
        movf 	RCREG,W 

;--------------------------
;	MAIN PROGRAM
;--------------------------
		
		call 	LCD_Init
		call	LCD_Line1

;        clrf 	dataL
;settle  decfsz	dataL,F		; Sync comms with PC
;        goto 	settle

		
			
ciklus	

		call	Delay100
		call 	fogad
		goto 	ciklus


;--------------------------		
;Initialise LCD
;--------------------------
LCD_Init
		movlw	0x20				;Set 4 bit mode
		call	LCD_Cmd

		movlw	0x28				;Set display shift
		call	LCD_Cmd

		movlw	0x06				;Set display character mode
		call	LCD_Cmd

		movlw	0x0d				;Set display on/off and cursor command
		call	LCD_Cmd

		call	LCD_Clr				;clear display

		retlw	0x00
;-------------------------
;UTASÍTÁS KIADO RUTIN
;-------------------------


LCD_Cmd	
		movwf	templcd
									;send upper nibble
		andlw	0xf0				;clear upper 4 bits of W
		movwf	LCD_PORT
		nop
		nop
		bcf		LCD_PORT, LCD_RS	;RS line to 0
		call	Pulse_e				;Pulse the E line high		
		movf	templcd,	w		;send lower nibble
		andlw	0x0f
		movwf	templcd				;clear upper 4 bits of W
		swapf	templcd,	w
		movwf	LCD_PORT
		nop
		nop
		bcf		LCD_PORT, LCD_RS	;RS line to 0
		call	Pulse_e				;Pulse the E line high

		call 	Delay5
		retlw	0x00

;--------------------------
;SZOVEG KIIRO RUTIN
;--------------------------

LCD_Char
		movwf	templcd				;send upper nibble
		andlw	0xf0				
		movwf	LCD_PORT
		nop
		nop
		bsf		LCD_PORT, LCD_RS	;RS line to 1
		call	Pulse_e				;Pulse the E line high
		movf	templcd,	w		;send lower nibble
		andlw	0x0f
		movwf	templcd				;clear upper 4 bits of W
		swapf	templcd,	w		;also,-felso bitek csereje
		movwf	LCD_PORT
		nop
		nop
		bsf		LCD_PORT, LCD_RS	;RS line to 1
		call	Pulse_e				;Pulse the E line high
		bcf		LCD_PORT, LCD_RS
		call 	LCD_Busy
		retlw	0x00

;--------------------------
;	LCD VEZÉRLOK
;--------------------------

LCD_Line1	
		movlw	0x80				;move to 1st row, first column
		call	LCD_Cmd
		retlw	0x00

LCD_Line2	
		movlw	0xc0				;move to 2nd row, first column
		call	LCD_Cmd
		retlw	0x00

LCD_Line1W	
		addlw	0x80				;move to 1st row, column W
		call	LCD_Cmd
		retlw	0x00

LCD_Line2W	
		addlw	0xc0				;move to 2nd row, column W
		call	LCD_Cmd
		retlw	0x00

LCD_CurOn
		movlw	0x0d				;Set display on/off and cursor command
		call	LCD_Cmd
		retlw	0x00

LCD_CurOff
		movlw	0x0c				;Set display on/off and cursor command
		call	LCD_Cmd
		retlw	0x00

LCD_Clr	
		movlw	0x01				;Clear display
		call	LCD_Cmd
		retlw	0x00

LCD_Busy
		bsf		STATUS,	RP0			;set bank 1
		movlw	b'11110110'			;set Port for input
		movwf	LCD_TRIS
		bcf		STATUS,	RP0			;set bank 0
									;set LCD for command mode
		bsf		SW_PORT, 0			;setup to read busy flag
		bsf		LCD_PORT, LCD_E
									;read upper nibble (busy flag)
		movfw	LCD_PORT
		bcf		LCD_PORT, LCD_E		
		movwf	templcd2 
		bsf		LCD_PORT, LCD_E		;dummy read of lower nibble
		bcf		LCD_PORT, LCD_E
		btfsc	templcd2, 7			;check busy flag, high = busy
		goto	LCD_Busy			;if busy check again
		bcf		SW_PORT, LCD_RW
		bsf		STATUS,	RP0			;set bank 1
		movlw	b'00000110'			;set Port for output
		movwf	LCD_TRIS
		bcf		STATUS,	RP0			;set bank 0
		return

Pulse_e	
		bsf	LCD_PORT, LCD_E
		nop
		bcf	LCD_PORT, LCD_E
		retlw	0x00


;-----------------------------
;	GPS VEVO JELENEK FOGADASA
;-----------------------------
fogad 	
		btfss	PIR1,RCIF         ; (5) check for received data
        goto 	fogad
		bcf		PIR1,RCIF
		movf 	RCREG,	W			; save received data in W
		clrf	RCREG
		call 	LCD_Char	            
		return 
;------------------------------
;kiiras
;------------------------------


kiir	
		clrf	TXREG
		btfss	TXSTA,1
		goto 	kiir
		movlw	b'101010101'
		movwf	TXREG
		


;-----------------------------
;	KESLELTETESEK
;-----------------------------


Delay255	
		movlw	0xff		;delay 255 mS
		goto	d0
Delay100
		movlw	d'100'		;delay 100mS
		goto	d0
Delay50
		movlw	d'50'		;delay 50mS
		goto	d0
Delay20
		movlw	d'20'		;delay 20mS
		goto	d0
Delay5
		movlw	0x05		;delay 5.000 ms (4 MHz clock)
d0		movwf	count1
d1		movlw	0xC7			;delay 1mS
		movwf	counta
		movlw	0x01
		movwf	countb
Delay_0
		decfsz	counta, f
		goto	$+2
		decfsz	countb, f
		goto	Delay_0

		decfsz	count1	,f
		goto	d1
		retlw	0x00

;-------------------------
;	SZOVEG
;-------------------------
text
		movlw	'D'
		call	LCD_Char
		movlw	'e'
		call	LCD_Char
		movlw	'n'
		call	LCD_Char
		movlw	'i'
		call	LCD_Char
		movlw	's'
		call	LCD_Char
		movlw	'z'
		call	LCD_Char
		end