Driving a Crystalfontz LCD with a Mega 128

Recently had a reason to use a Crystalfontz graphics LCD on a Mega 128, and had a few problems finding an easy (down to earth) driver anywhere on the net, so i bit the bullet and wrote my own. I thought i would share it with everyone else as i'm sure that someone else out there might want to do the same. It was written with the ICCAVR v6 compiler.

I happened to be using the Crystalfontz graphic LCD model (CFAG12232DYYHN) which can be seen at: http://www.crystalfontz.com/products/12232...G12232DYYHN.pdf
It is very cheap and reliable.

I was driving it with a Mega 128 clocked at 8Mhz, but i think the code should be flexible enough to handle any clock speed (no guarantees though!!).

After reading the manual for the LCD, i should tell you how i had the pins connected. (Warning - this will probably not make sense unless you have read the manual in the link provided above ^):

LCD Pin connectod to M128 Pin
--------------------------------------
R/W to PORTD6
A0 to PORTG3
E1 to PORTD1
E2 to PORTG4
D0->D7 to PORTF0->PORTF7

I have attached the files to this post, so you can download them. You will need to make your own main function from which you should call the lcd_init() function which sets the lcd up, and then you can go ahead and print stuff to the LCD by using my:


void lcd_printstring(int row, int col, char* string)
function, or my

void lcd_printnum(int row, int col, int num)
function.

My routines allow you to print to 4 lines (rows) and up to 20 characters (colums). It does not word wrap, so don't bother trying to print more than 20 chars per line.

I apologise that the code is not well commented, but i'm sure it will save you a heap of time anyway.

Please feel free to contact me with any questions about it (or any feedback in general).

les060@csiro.au