HI, I have not abandoned the forum.
Last year actually I have been in Tokyo and Osaka.
Over the years i have built some LED matrix scrolling message circuits.
You know the problem maybe- there are many different displays and controller chips.
Each time, the source code needs to be changed.
Display size can be different too.
I have worked out a solution!
The LED matrix configuration is defined with a pin order table.
IO is done in random order- pin port address & bitmask are read from a table for each bit.
A display bitmap buffer is used, all of the scrolling message is precomputed. So a proportional font can be used! This makes it possible to have a 5 pixel high font.
Once you understand how the tables work, you can port it to any controller, you can use any LED matrix modules, even self-made matrix. You can cconnect to random IO pins.
1. It is of course much slower than full port writes. 8 MHz is enough to update 15x5 flicker free
2. It is not yet moving the view window (but that is trivial only needs a few lines code)
3. Midrange PICs only havee 80 bytes continuous RAM. So the message cant be so long
All is included here, with source code:
http://aranna.altervista.org/dragonsnes ... 0078125000