Here you can see the full ASCII character set displayed on the 3595 lcd. It was actually amazingly simple to get to this point from the previous “helloworld” firmware.
The most important change that was made is that I upgraded to an ATmega168 to solve my programming space problem. This chip will still operate at 3.3v which is the operating voltage of the LCD. The additional 14kb of programming space should give me plenty of room to grow. I would also like to dabble with SD card compatibility and this chip should allow me to do so (I’ve never looked into it so I may be wrong).
For the character set I borrowed the array and the function to read the characters from memory from a past project. I then wrote a function to handle advancing a “virtual cursor” after each character is written. This function handles wrapping to the next row when about to overflow as well as wrapping from the bottom to the top. The last thing was a function to parse the character information and write it on the screen.
I’ll provide more details in my next update.