I really want a calculator mode built into my keyboards.
My Cherry (Reuters) G80-9009 Keyboard has a calculator mode built in. It is way cool.
I have some code for a simple RPN calculator that runs on a Beetle ATmega32u4-based
Microcontroller that I'd be happy to share. It's not tied into the rest of the keyboard code, yet.
16 characters is not an unreasonable display foe a lot of calculations, for example it can display
-9,999,999.99999, or similar.
If you're doing modifiers on a more complex programable keyboard you could display something like:
- ____ - No shift down
- Shft - Single-shot shift mode (next key is shifted)
- SHFT - Shift modifier locked down (everything is shifted until Shift is pressed again)
Repeat for Ctl, Win, Opt, so with everything locked you get "SHFT CTL WIN OPT" displayed. (16 characters, 1 row)
If you support use SpaceFn you could display that and the current layer (name or number) on line 2.
All the best!