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.

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.

This is the SB116, an 8-bit programmer’s calculator powered by an Arduino Nano. It features a 128 x 64 pixel monochrome OLED display and can be powered by either a USB port or three AAA batteries.