PX41CX

[agarza]

So, I really wanted the full functionality of the HP41CX for the PX DIY calculators.
But the ATMEGA328 has very limited memory (both flash and ram). Fortunately, there is a relatively new microcontroller from Microchip. Same physical size and thru hole (28 pins) but with lots of ram and flash.

So, here’s where I’m at:
- Clock/Timer with a resolution of 250ms (instead of the original 100ms)
- Full RAM (319 Registers)
- Full Extended Memory (600 Registers)
- Enough flash to store several modules. (Currently only tested with advantage module and Games module at once.)
- Consumes about 7µA in sleep mode. (The CR2032 coin battery should last more than 2 years)
- Same 192x64 LCD
- Same keypad
- Same landscape form as other PX calculators.

The idea is to make it in portrait form, like the original HP14C.

If anyone is interested in testing, please PM me.