Wow, this is such a cool hack. Taking a Casio F-91W—literally the indestructible watch—and giving it a microcontroller brain while keeping that retro LCD? Pure genius. The pluggable sensor module (starting with a thermometer!) is what sold me. Now I’m daydreaming about slapping on an air quality sensor, an NFC chip, or… honestly, why not a tiny radiation detector?

But flashing firmware via USB on a Casio? That’s the kind of absurdly cool detail that makes me love hardware tinkering. It’s like giving your grandpa’s old pickup truck a Tesla battery but keeping the patina.

Huge props for keeping it open and hackable.