I bought recently AVR dev. board with AT90CAN128 and LCD Touchscreen 160x160 dots. I am playing around with the demo software, which is writing some text on the screen.
The problem is that it is using almost all RAM (>90%), so there is not much spare space to build a custom application, and especially not if I want to implement FatFs on the MMC. I can see that the demo is writing first all the texts in a 3kB bitmap with 160x160 dots, which is afterwards sent to the graphic LCD in a stream with 4-bits, and clocking CP, LP and FLM. This bitmap is built by mapping the string characters with the fonts stored in the progmem.
Is there any alternative to reduce the size of the RAM?
I tried to reduce the bitmap 20x times to represent just a single line of text, which I update with new text after the previous line is written. However, this doesn't work well since interrupting the display clocking while updating the small bitmap creates horizontal lines on the bottom of each row.
I reconsidered storing the texts i.e. the menus in the Flash memory, but some screens should have dynamic texts (file directories), so it is difficult to avoid using the RAM.
Any good ideas?