Srcolling Text only 37 Bytes: Resolved

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I think found a little bug.
According to the help, a string with the length of 40 characters is allowed for controllers with more than 367 bytes of RAM.
In my project with the PIC18F25K22 and glcd1306 128x64 Pix in TEXTONLY mode and Protect_Overrun, I can only use 37 bytes without errors. With 38-40 bytes it comes to misrepresentations at the first position, but the program works, it only looks stupid.

Code: snippet

DIM scrolltext AS STRING
'          "1234567890123456789012345678901234567890"
scrolltext="U/D=Ausw M=stellt U,D gleichz=Ende .."  ; OKAY
'scrolltext="U/D=Auswahl M=stellt U,D gleichz=Ende " ; WRONG

function menuLine
        scrolltext=mid(scrolltext,2)+left(scrolltext,1,1)
        glcdPrint(0,56,scrolltext)
wait delay
end function

RAM used:

Chip resource usage:
Chip Model: 18F25K22

Program Memory: 8454/16384 words (51.6%)

RAM: 547/1536 bytes (35.61%)

[Anobium]

Use the size parameter where * 128 would size the string for you.

DIM scrolltext AS STRING * 128 'other big number

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No, just tried it before, this does not fix the prob. 37 is limit
I can share two Videos. Or build an example

[Theo]

@bed
Try this one:
The Syntax of Left is:

output = Left(source, count)

and not

output = Left(source, count ,count)

Mfg, Theo.

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Ok, thanks.
I had copied it from my older Project...
But
scrolltext=mid(scrolltext,2)+left(scrolltext,1)
Same result. :-(

[Anobium]

I think Theo meant....as left is output = Left(source, count)

try
=mid(source, start, count)

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This is what happens when you use foreign code without your own thoughts.
(it has worked before )

It remains the astonishing thing that despite ignoring the syntax of mid and left you get a very small and limited working code... Which of course you shouldn't do, because who knows when the code will fall on your face later :-)
I have now found a less elegant method, which works fine with longer strings.

DIM scrolltext AS STRING * 140
'          "1234567890123456789012345678901234567890" ; 40
scrolltext="                  Here comes a long example text which stands for a huge Description for the possibilities in a menu                  "
DIM scroll,laenge AS BYTE
#DEFINE maxtextdisplay 18 ' We can display a max of 18 Char in a row
laenge=len(scrolltext)
scroll=1 
glcdPrint(0,0,"Scrolltxt len:")
glcdPrint(105,0,laenge)
do forever
'   here is the normal main loop with button check etc.
    menuLine

LOOP

sub menuLine
    glcdPrint(0,56,mid(scrolltext,scroll,maxtextdisplay))
    wait delay
    scroll++
    IF scroll=laenge - maxtextdisplay THEN
        scroll=1
    END IF

end sub

So, the downside is using more code and an extra variable

[Anobium]

I have updated the Help to help others with the MID() function in the future.

See https://github.com/Anobium/Great-Cow-BASIC-Help/blob/master/source/mid.adoc

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There is always something positive in a false assumption. Last but not least, my scroll text led to an improvement 😘