Hello!
Indeed, there is huge difference between GLCD and Alphanumeric LCD. If you want to display only
characters then I will strongly recommend you to use Alphanumeric LCD rather than GLCD. In GLCD
you can display images only. Even you are displaying Characters then you have generate pixel
information of each character and treat as a Image.
Indeed it's easier with a character LCD, but for another point of view, character LCD looks very much
outdated and (well, that's a matter of taste) it's ugly.
Now to answer the original question:
If it's a 128 x 64, I guess it's monochrome 1-bit LCD, right?
Usually all the 1-bit controller don't display 1 pixel, but 8 pixels at one, and these pixels are displayed
vertically. So if you keep writing the same byte, you will get horizontal lines depending on the byte value.
Example: if you write 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, you will get:
Code:
*_______
_*______
__*_____
___*____
____*___
_____*__
______*_
_______*
where _ is a blank and * a black pixel.
Now if you want to write a A, same method:
Code:
______
__*___
_*_*__
*___*_
*****_
*___*_
*___*_
______
In this example, you have to write:
0x78, 0x14, 0x12, 0x14, 0x78, 0x00, the last 0 being a space before the next letter.
Therefore what you have to do first is to find an alphabet,
write a function to write a char, then a string, etc...
And of course, the big advantage is that you can draw icons without any limitation except
your CPU flash.
Dora.