Font in PROGMEM example

[BrynM]

Font storage in PROGMEM example.

I'm working on a project where memory is a premium, but still wanted to use the simple font you'd created. Thus, I moved the font to PROGMEM. I thought others might make use of it too and wanted to contrib something back to you.

I collapsed both draw functions into a single drawPMem() function to make for less index juggling (the call to pgm_read_byte_near() needs full indices). Yes, that makes for a deep nested for, but it was cleaner to read for noobs than the index juggling.

Thanks for the library!

[BrynM]

Sorry for the force push to my fork. I wanted to squash the commits so your review would be cleaner.

[bartoszbielawski]

Hi,

Thanks for the extra code. Your approach makes sense on the memory limited device.
Since you're using AVR specific functions, would you mind adding some #ifs and #errors to print messages if the CPU is not AVR?

Cheers,
Bartosz

[BrynM]

Sure. Do you have any examples I can look at for what to flag or how you'd like it handled? I hadn't considered it being AVR-specific, but it indeed is.

[bartoszbielawski]

I think there's an __AVR__ #define while using avr-gcc. Could you check it? I suggest just raising an error if the MCU is NOT AVR.

[BrynM]

Sorry for the wait. I ordered an ESP32 to test with since I found out there's some support for a PROGMEM concept there. If I can get that to work, I'll include it as a possibility too.

[bartoszbielawski]

Don't worry, we're not in a hurry :)