Harold,

I could use something like this for a project coming up soon.
Would it be asking too much to ask if you would allow me to 
Copy your CPLD setup and the accompanying code to use in my project?
You can email your responses to me offline at projects@jpes.com.
I'll use this address so your response will be easy to find.


						Thanks and Regards,

							 Jim

-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf
Of Harold Hallikainen
Sent: Wednesday, April 25, 2007 10:18 AM
To: Microcontroller discussion list - Public.
Subject: Re: [PIC] 128x64 graphics LCD interface


>
>   OK, so what about just sending a character....say....A.  I suppose 
> thats what the graphics libraries such as ramtec supplies, in that you

> say send an A and it sends out the page, and then the column address 
> to 'turn on' the pixels.  So each 'character' is a subroutine thats
called?
>  Or is there a easier method....or has someone else done this before, 
> maybe not for this controller but another one.  I think Scott D was 
> doing something with font experiments but I don't recall what 
> controller or resolution he was using.  I was thinking for a graphic 
> module interface you would end up needing alot of RAM not flash to do
this?


I have a project with a PIC24H driving a CPLD that interfaces to a RAM
and a graphic display. To the PIC, it looks like an external RAM. I can
set up an address corresponding to a position on the screen, then read
or write that address. The CPLD autoincrements to the next pixel
position (including from the end of one line to the start of the next).
I have a C function that draws a character. The start of my font table
includes the X and Y size of the character, then the bit pattern for
each character. I used the Character Set Extractor at
http://www.piclist.org/techref/datafile/charset/extractor/charset_extrac
tor.htm
. My DisplayCharacter function pulled the pixels from the table and
output them to the LCD, dropping to the next line at the right edge of
the character. I have a couple global variables that define the
foreground and background colors that are used to draw the characters.
At the end of drawing the characters, the CPLD is set to the top left
corner of the next character so I can just feed them one after another
to print strings. The function also allows for different character sets
(especially different sizes), which is why I put the Xsize and Ysize at
the start of the table.

Harold


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