Before there were smartphones, there were personal digital assistants like the Palm Pilot, Handspring Visor, and Compaq/HP iPAQ line of devices. And before those, there were really basic PDAs, like the Psion Organiser, which basically had the kind of features you’d also find on a calculator watch.
While you might be able to find one of those old-school organizers on eBay, YouTuber Volos Projects decided to build one from scratch using an Arduino Nano, a custom printed circuit board, and a tiny OLED display.
The Arduino Pocket Computer isn’t exactly powerful by modern computer standards. But it has all the features you’d find on an digital organizer from the 1980s or early 90s, including a phone book, calendar, stopwatch, calculator, and support for some basic games.
It’d probably be unrealistic to expect a handheld computer powered by an Arduino Nano to do much more than that. It’s a tiny board with a 16 MHz ATmega328 microcontroller 32KB of flash memory, and 2KB of SRAM.
The Arduino Pocket Computer may not exactly be practical (the tiny display is barely large enough to display games or calendar appointments, and the exposed components would likely snag on your pocket if you tried to carry this thing with you). But it’s a pretty impressive DIY project, and if you’d like to try making your own Volos has posted links that you can use to order a printed circuit board in description of the YouTube video, and you can find code for the software that runs on the device at GitHub.
via Arduino Blog