Scrolling text on an LCD

' A SIMPLE "MESSAGE SCROLLING" FOR BEGINNER
' SIMPLE COMMANDS YET POWERFUL ENOUGH TO BURN YOUR MESSAGE
' 28 SEPT 2004
' UNLIMITED MESSAGE [ MEMORY DEPENDENT(",) ]
' BY: Dolci
' PROCEDURE: JUST CHANGE THE VALUE OF THE STATEMENT WITH "$$$ MARKED" TO FIT TO YOUR LCD LENGTH
' TO REMOVE THE FLASH MESSAGE JUST DELETE THE STATEMENT WITH "REMOVE THIS LINE AS YOU LIKE"

DEVICE 16F877 ' WE ARE USING...(ANY TYPE:CAPABLE OF DRIVING LCD)

' CHANGE CONFIG DIREVTIVES AS PER DEVICE USE
CONFIG WDT_OFF,XT_OSC,PWRTE_ON,LVP_OFF,CP_OFF,DEBUG_OFF,W RTE_OFF,CPD_OFF,BODEN_OFF

ALL_DIGITAL=TRUE ' COMMENT OUT IF NON ADC OR NON COMPARATOR CHIPS

' CHAGNGE LCD DECLARATIONS AS PER YOUR CHOICE
DECLARE LCD_TYPE ALPHA ' Inform the compiler as to the type of LCD
DECLARE LCD_DTPIN PORTB.4 ' Used for 4-line interface.
DECLARE LCD_ENPIN PORTB.2 ' Assigns the Port and Pin that the LCD's EN line will attach to.
DECLARE LCD_RSPIN PORTB.3 ' Assigns the Port and Pins that the LCD's RS line will attach to.
DECLARE LCD_INTERFACE 4 ' 4-line or 8-line interface is required by the LCD.
DECLARE LCD_LINES 2 ' Inform the compiler as to how many lines the LCD has

' *** DEFINE VARIABLES ***
DIM MESSAGE_ARRAY[20] AS BYTE ' $$$ LENGTH OF LCD
DIM DATUM AS BYTE ' DATA STORAGE
DIM Y AS BYTE ' JUST A COUNTER
DIM FLASH_ARRAY[20] AS BYTE ' "FLASH-REMOVE AS YOU LIKE"
DIM X AS BIT ' "FLASH-REMOVE AS YOU LIKE"
' *** ALIAS CONSTANT ***
SYMBOL EOM = 1 ' END OF MESSAGE
SYMBOL SPEED = 190 ' $$$ SCROLL SPEED
SYMBOL LCD_LENGTH = 19 ' $$$ WE ARE USING 2x20 LCD (IN THIS CASE 0-19)

DELAYMS 500 ' WAIT LCD TO STABILIZED
CLS ' CLEAR SCREEN

' *** HERE IS YOUR MESSAGE *** NOTE: No double space! (1 is the End Of Message)
DATA "Created September 28,2004... PROTON PLUS 2.1.5 by CROWNHILL ASSOCIATES... "
DATA "Programed by DOLCI... a_balina@hotmail.com...This e-mail address is being protected from spam bots, you need JavaScript enabled to view it kwatog217@yahoo.com...This e-mail address is being protected from spam bots, you need JavaScript enabled to view it Manila, Philippines... MEMORY DEPENDENT"
DATA " SCROLLING MESSAGE!!!",1
GOTO START

'------------------------------------------------------------------------------------
' (REMOVE THIS LINES AS YOU LIKE)
'----FLASH MESSAGE----
FLASH:
IF X=0 THEN
STR FLASH_ARRAY=" "
X=1
RETURN
ENDIF
IF X=1 THEN
STR FLASH_ARRAY=" PROTON PLUS V2.1.5 "
X=0
RETURN
ENDIF
-------------------------------------------------------------------------------------

SCROLL_MESSAGE:
GOSUB FLASH ' REMOVE THIS LINE AS YOU LIKE
PRINT AT 1,1,STR MESSAGE_ARRAY ' DISPLAY THE MESSAGE
PRINT AT 2,1,STR FLASH_ARRAY ' "REMOVE THIS LINE IF ANNOYING"
DELAYMS SPEED ' WAIT
FOR Y=0 TO LCD_LENGTH-1 ' MAKE A LOOP
MESSAGE_ARRAY[Y] = MESSAGE_ARRAY[Y+1] ' SHIFT LEFT THE BYTES CONTENTS
NEXT ' FINISH THE JOB
RETURN ' BYE!

START:
Y=0 ' CLEAR POINTER
REPEAT ' DO A LOOP
MESSAGE_ARRAY[Y]=" " ' CLEAR ARRAY
INC Y ' INCREMENT POINTER
UNTIL Y=LCD_LENGTH ' FINISH THE JOB

LOOP:
RESTORE ' POINT TO FIRST CHARACTER OF DATA
WHILE 1=1 ' MAKE AN ENDLESS LOOP
READ DATUM ' GET THE FIRST CHARACTER... AND SO ON....
IF DATUM=EOM THEN BLANK_TXT ' TRACK END OF MESSAGE & EXIT IF FOUND
MESSAGE_ARRAY[19]=DATUM ' $$$ SAVE THE DATA TO LAST BYTE OF THE ARRAY
GOSUB SCROLL_MESSAGE ' GO AND PLAY
WEND ' END OF STATEMENT

BLANK_TXT:
IF MESSAGE_ARRAY[10]=" " THEN ' $$$ TRACK THE FIRST BLANK CHARACTER
IF MESSAGE_ARRAY[11]=" " THEN ' $$$ TRACK THE SECOND BLANK CHARACTER
GOTO LOOP ' IF FOUND? GO BACK TO LOOP
ENDIF ' END OF 2ND STATEMENT
ENDIF ' END OF 1ST STATEMENT
MESSAGE_ARRAY[19]=" " ' $$$ STORE A BLACK CHARATER TO THE LAST BYTE OF THE ARRAY
GOSUB SCROLL_MESSAGE ' GO AND FINISH THE PLAY
GOTO BLANK_TXT ' DO IT AGAIN
END ' END OF PROGRAM