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Kod: Markera allt

; LCD Test Program v1.0 made by Erik Henriksson
; This program is ment to run at a PIC16F628A @ 20MHz .
; It can be run at any pic with 8 io-pins if you make some small changes.
; Pinmap is: 
; RB0-3 = D4-7
; RS    = 6
; RW    = 7
; EN    = 5
; The control pins is easy to change. See "Alias declarations".
; If you want to run at 4MHz you have to change the delays to speed the code up. If
; you aren't in a hurry you can drive without any changes.
; 
; Feel free to copy but write my name in your project and send me a mail so I can see
; how popular the code is. =)
; Email address is: eriikh(-at-)hotmail(-dot-)com
; (Change to the real address, the extra characters is only for spam removing.)
;
; Enjoy!
;
;*********************************************
; Start of program
;*********************************************
; CONFIG, INCLUDE & LIST
;*********************************************
	__CONFIG 0x036A 
	INCLUDE p16f628a.inc
	LIST p=16f628A
;*********************************************
; End
;*********************************************
; What to do when reset
;*********************************************
	Org 0x001
	Goto Start
;*********************************************
; End
;*********************************************
; Alias declarations
;*********************************************
ISR		Equ 0x004
En		Equ 5
RS		Equ 6
RW		Equ 7
;*********************************************
; End of Alias declarations
;*********************************************
; Variable declaration
;*********************************************
;Avalible RAM in bank0: 0x0020-0x06F
;
; Delay variables
d1		Equ 0x020
d2		Equ 0x021
d3		Equ 0x022
d4		Equ 0x023
; Lcd variables
Hi_bits	Equ 0x024
Lo_bits	Equ 0x025
tmp 	Equ	0x026

;*********************************************
; End of Variable declaration
;*********************************************
; Timer interrupt
;*********************************************
	Org isr
	Retfie
; Do nothing
;*********************************************
; End of Timer interrupt
;*********************************************
; Subroutines
;*********************************************
Delay_5ms ; Make a delay of exactly 5ms = 25000cykles
			;24993 cycles
	movlw	0x86
	movwf	d1
	movlw	0x14
	movwf	d2
Delay_5ms_0
	decfsz	d1, f
	goto	$+2
	decfsz	d2, f
	goto	Delay_5ms_0

			;3 cycles
	goto	$+1
	nop

			;4 cycles (including call)
	return

;******

Delay_160us ; Make a delay of exactly 160us = 800cykles
			;793 cycles
	movlw	0x9E
	movwf	d1
	movlw	0x01
	movwf	d2
Delay_160us_0
	decfsz	d1, f
	goto	$+2
	decfsz	d2, f
	goto	Delay_160us_0

			;3 cycles
	goto	$+1
	nop

			;4 cycles (including call)
	return

;******

Enable
	bsf portb, En ; pulse the LCD Enable high
	nop
	nop
	nop
	nop
	nop
	bcf portb, En ; pulse the LCD Enable low
	nop
	nop
	nop
	nop
	nop
	return

;******

SendCmd4bit
; Send W to lcd trought 4bit interface
; You must set RS first if you are sending a command
	clrf hi_bits ; Set hi_bits to zero
	clrf lo_bits ; Set lo_bits to zero
	clrf portb ; Set portb to zero
; Load W into lo_bits and hi_bits
	movwf tmp
	movwf hi_bits
	movwf lo_bits
;lo_bits preparation
	movlw 0x0F
	andwf lo_bits, 1 ; Remove the high bits and store in lo_bits
;hi_bits preparation
	movlw 0xF0
	andwf hi_bits, 1 ; Remove the low bits
	swapf hi_bits, 1 ; Swap (=switch) low and high bits
;Send the bits
;Hi:
	movfw hi_bits ; Move hi_bits to W
	addwf portb, 1 ; Add the bits instead of moving them so you can set RS before if you want. Store in portb
	call Enable
	call delay_160us ; lcd busy delay
	movfw hi_bits ; Add hi_bits again to W, the delay_160ms is using it (W). (%¤&#½!)
	subwf portb, 1 ; Store in portb
;Lo:
	movfw lo_bits ; Move hi_bits to W
	addwf portb, 1 ; Add the bits so you can set RS before if you want . Store in portb
	call Enable ; Set enable for 3,2us
	call delay_160us ; lcd busy delay
	movfw lo_bits ; Add lo_bits again to W, the delay_160ms is using it (W).
	subwf portb, 1 ; Store in portb
;Done
	return

;*******

SendText4bit
; Send W to lcd trought 4bit interface
; This is for sending text so RS is Enabled
	clrf hi_bits ; Set hi_bits to zero
	clrf lo_bits ; Set lo_bits to zero
	clrf portb ; Set portb to zero
; Enable RS
	bsf portb, RS
; Load W into lo_bits and hi_bits
	movwf tmp
	movwf hi_bits
	movwf lo_bits
;lo_bits preparation
	movlw 0x0F
	andwf lo_bits, 1 ; Remove the high bits and store in lo_bits
;hi_bits preparation
	movlw 0xF0
	andwf hi_bits, 1 ; Remove the low bits
	swapf hi_bits, 1 ; Swap (=switch) low and high bits
;Send the bits
;Hi:
	movfw hi_bits ; Move hi_bits to W
	addwf portb, 1 ; Add the bits instead of moving them so you can set RS before if you want. Store in portb
	call Enable
	call delay_160us ; lcd busy delay
	movfw hi_bits ; Add hi_bits again to W, the delay_160ms is using it (W). (%¤&#½!)
	subwf portb, 1 ; Store in portb
;Lo:
	movfw lo_bits ; Move hi_bits to W
	addwf portb, 1 ; Add the bits so you can set RS before if you want . Store in portb
	call Enable ; Set enable for 3,2us
	call delay_160us ; lcd busy delay
	movfw lo_bits ; Add lo_bits again to W, the delay_160ms is using it (W).
	subwf portb, 1 ; Store in portb
;Done
	return
;*********************************************
; End of Subroutines
;*********************************************
; Start
;*********************************************
Start
	Clrf porta ; Init porta
	Clrf portb ; Init portb

	Banksel trisb ; Select bank1

	Movlw 0x00 ; Data direction value, 0 = output
	Movwf trisb ; Write to trisb
	Movlw 0xFF
	Movwf trisa
	Banksel portb ; Select bank0
;*********************************************
; End of Start
;*********************************************
; Main
;*********************************************
	Call delay_5ms
	Call delay_5ms
	Call delay_5ms
	Call delay_5ms ; Wait for lcd to start
	Movlw 0x03
	Movwf portb
	Call Enable ; Send 0x03
	Call delay_5ms
	Call Enable ; Send 0x03
	Call delay_160us
	Call Enable ; Send 0x03
	Call delay_160us
	Movlw 0x02
	Movwf portb
	Call Enable ; Send 0x02
	Call delay_160us

	Movlw 0x28 ; Interface length is: 4bit, 2 lines, 5x7
	Call SendCmd4bit
	Movlw 0x10 ; Turn off the display
	Call SendCmd4bit
	Movlw 0x01 ; Clear the display
	Call SendCmd4bit
	Movlw 0x06 ; Shift cursor on every written byte
	Call SendCmd4bit
	Movlw 0x0F ; Turn display on, cursor on, cursor blinking on
	Call SendCmd4bit
;Init done
	Movlw 0x45 ; Send "E"
	Call SendText4bit
	Movlw 0x72 ; Send "r"
	Call SendText4bit
	Movlw 0x69 ; Send "i"
	Call SendText4bit
	Movlw 0x6B ; Send "k"
	Call SendText4bit
	Movlw 0x21 ; Send "!"
	Call SendText4bit

;*********************************************
; End of Main
;*********************************************
; End of Program
;*********************************************
	END