load font files ffrom external SD card?

did you know when you are in the country that programming arduino and research is expensive? 20$ for 3gb and 6GB a week i think i need a better job js...

i digress is there somewhere that i havent seen a library to load fronts form the SD card? if not im probably going to build one. maybe that compares the bits to the table on the sd card and then loads the information to LCD. simple neat and to the point. also saves progmem, becasue i got 2GB of sd and only 256k flash... and with the current project hitting 25% of flash im seriously going to have to offload some stuff.


What kind of LCD are you using? Does the LCD allow storing the font data inside it?

If not, I'd be much more worried about RAM usage and performance. If you pull the font data from the SD card where are you going to store it? (hint: it will be in RAM and RAM is much smaller than flash), and how much free RAM do you have? And if you don't store it it RAM, you would have to read it from the SD card every time you print a character and that would really slow things down.

--- bill

You can access Font files in Program Flash, external Flash chip, SD card, EEPROM, SRAM

As Bill has warned, there are many things to consider.

In practice, most Apps are fine with 2 or 3 fonts stored in Program memory. And that is how most libraries do it.

It is different if you are Chinese. You need very big Fonts. You probably use an external Font chip. Controllers like ST7920 or RA8875 come with standard Chinese Fonts on-chip.


No, there isnt a font chip on my lcd.

i was considering a font library. now that i have a bit of experience messing with the fonts i think i may just make a serial LCD back pack and fill up the rest of the program memory with fonts, but this will be a future expansion for now i have learned that there are some pretty sever font limitations since the anti aliasing algorithms don't exist as far as i can see for arduino to make the cool fonts pretty . fontconvert kind of just smooshes them to be flat bitmaps. i added 8 fonts at 6 different point sizes to my mega and only lost 2% of my program, which isnt that much of a sacrifice. i think if i do do external fonts im going to us FRAM, its faster than this turtle sd any how but it was a noble idea..

really why i was curious about this is becaus ehte user of my application would be able to change the font just by dropping in the font file to SD card. which may still be viable if they drop it in to sd and it converts it and stores it to the FRAM. and then uses it because im not thinking there is a way to get it in progmem after the arduino is programmed.