Featuring an Arduino Nano microcontroller board and the keyboard from a small numeric keypad the LCD display the calculator is powered by a set of AA batteries through a DC-to-DC converter.

There’s something about Reverse Polish Notation (RPN) and the calculators that use it. It calls to mind a time when a calculator was a serious tool, and not just a throwaway toy. Created in t… ...

This calculator solves a more practical problem — the dearth of RPN calculators on the market with the correct keyboard feel, specifically with the large keys and light touch he desired.