The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52 .

To build this project, all you need is three main components: an Arduino Uno, a 16x2 LCD, and a push button. You can connect everything to a breadboard to keep it simple.

The chip gets programmed in an Arduino Uno and then transplanted into the calculator, a neat trick if you don’t have a dedicated programmer handy. Given how cheap Arduino clones can be had ...

Arduino enthusiasts or those looking ... The CleO Comes complete with 20 tutorials and 20 projects allowing you to learn more ... resistive touch TFT display GUI to their Arduino UNO projects.