Help with LCD Scroll

[Art]

So since that was meaningless if you can’t scroll on LCD already, I’ll try an example.

string var byte [16] ‘ because I assume it’s one line of a 2x16 display but you can change this
character var byte ‘ the current character
counter var byte ‘ a step counter and index
lindex var byte ‘ a lookup table index

Now how you’re getting the string in the first place you didn’t say, it could be being typed in serial,
or already stored in eprom or something. I’ll go with a longer than 16 char message stored in lookup table,
and put it in a subroutine at the end of the program.

lookuptable: ‘ get the next character from the table into the character buffer
LOOKUP lindex,[“CHECK IT OUT A SCROLLING TEXT DEMO!!!”],character ‘ 0-36 length message (37 characters in Human talk)
return

We need something to actually rotate the 16 char line buffer and drop the oldest byte off the end
whenever a new character is shifted in. This goes in a subroutine also at the end of the program.

'
rotatearray:				‘ rotate line array
for counter = 16 to 1 step - 1
string[counter] = string[counter-1]
next counter
string[0] = character			‘ insert new character byte at zero index
return
‘

Then a main cycle is needed to index the lookup table, call the lookup and rotate routines and
print the line to LCD. After the variable declarations and before the subroutines:

lindex = 0
CLEARLCD ‘ it’s been a while since I looked at LCDOUT, but whatever two byte code to clear LCD and home.
'
cycle:
HOMELCD ‘ it’s been a while since I looked at LCDOUT, but whatever two byte code to home LCD cursor.
'
gosub lookuptable
lindex = lindex + 1 ‘ increment lookup index
if lindex > 36 then ‘ limit lookup index to length of message
lindex = 0
endif
gosub rotatearray ‘ rotate line with new character at zero index

for counter = 0 to 15 ‘ print the line to lcd
LCDOUT string[counter]
next counter

pause 1000 ‘ delay to see one movement per second

goto cycle ‘ do cycle forever

Largely untested so if someone has a simulation with LCD pls feel free to run it