Whether you work in meters, feet, inches, or kilometers — or any number of other units corresponding to properties that you need to convey — conversions are a fact of life when making things. While this could mean pulling up a Google tab or flipping open a Machinery’s Handbook and doing a few hand calculations, neither is particularly convenient for shop use.

As an alternative, Kaleb Clark over at element14 came up with a dedicated desktop conversion calculator using an Arduino Uno and Cherry MX switches in a matrix arrangement as the main input method. A rotary encoder is also implemented to swap between functions and output is via a 4×20 LCD screen.

Although the device still needs a bit of programming work to be called “complete,” it’s currently able to handle an impressive variety of conversions.