Embedded Strings in your Code Space

[Darrel Taylor]

But it has to stop sometime.

When you add a final ,0 to the end of the line, DA generates a 0x0000 word. So only if the whole word is 0 will it consider it the end of the "string".

Any other 0 characters within the "string" are ignored.
<br>

[mister_e]

Got it..

StringOut:  ' Send the string out via Hserout
    Readcode Addr, TwoChars       ' Get the 14 bit packed characters
    IF TwoChars then
        Char = TwoChars >> 7      ' Separate first char
        if Char then              ' Look for Null char, Don't send if found
           hserout [Char]         ' Send first char
        endif

        Char = TwoChars & $7F     ' Separate second char
        if Char then              ' Look for Null char, Don't send if found
           hserout [Char]         ' Send the second char
       endif
       Addr = Addr + 1            ' Point to next two characters
       goto StringOut	          ' Continue with rest of the string
    ELSE
        Addr=Addr+1
        Goto StringOut
    ENDIF
return

[mister_e]

NARGH forget the above. It depend on the previous and the next string... wich doesn't happen with my first version with DT...mmm

[Darrel Taylor]

Forgotten

[mister_e]

Well, if we want to create and send a mix of String and Numeric Value, da is not the one to use even if it gives some codespace advantages.

O.K. for Text String only. So i'll stick to my first solution that used dt

Thanks for the tips anyway !

[Mike, K8LH]

Hi Guys,

Hope you don't mind me butting in...

I've been using a similar method for 18F' devices in assembler for awhile now and I wonder if you might need to account for the occasional odd length character string to make sure the address is word aligned before placing it back into TOS?

Regards, Mike

;
;  Example macro usage
;
        _Title  "K8LH Az/El Controller\r\n\n"
        _Print  "Satellite AOS:\r\n"
        _Print  "Satellite LOS:\r\n"

;******************************************************************
;
;  print the in-line string using Stack Pointer & TBLPTR
;
PutString
	movff	TOSH,TBLPTRH	; copy SP address to TBLPTR
	movff	TOSL,TBLPTRL	;
	clrf	TBLPTRU		;
PutNxt	tblrd	*+		; get character
	movf	TABLAT,W	; last character (00)?
	bz	PutXit		; yes, exit
	rcall	Put232		; else, print character
	bra	PutNxt		; do another
PutXit	btfsc	TBLPTRL,0	; odd address?
	tblrd	*+		; yes, make it even (fix PC)
	movf	TBLPTRH,W	;
	movwf	TOSH		; update the return stack
	movf	TBLPTRL,W	;
	movwf	TOSL		;
        return                  ;
;
;******************************************************************

[Squibcakes]

I'm using this for my LCD display, but what if....

I want to send two lines of text to my LCD?

Normally we would send $FE, $C0 to start the second line but coding this doesn't work using your example....

@ da "First line",$FE,$C0,"Second Line",0

I see you guys are doing this when sending serial data, by adding 13,10,0 to the string.

Cheers
J

[mister_e]

using DA it won't work. Da pack two ascii character in a 14bit packet... 2X7Bits
$FE (wich should be write h'FE') is over the 127 dec or 7F Hex.

What you can do is to use something else something like

DA "first line",1,2,"Second Line",0
.
.
.
If char = 1 then char = $FE
If char = 2 then char = $C0

[Homerclese]

I use DEBUG to get to my serial pic LCD readout at 2400 baud. I have been trying to replace the hserout functions in the "string storage" thread with my usual debug output with no luck. I get repeating characters but not the expected string. I see now where there may be an issue because of the 14 bit word length but how to correct this is not clear.