The Motif I wanted to use a compact device to measure and display the speed of some orbiting wheels. I quickly created a simple but compact digital tachometer using an Arduino Uno microcontroller and ...

Arduinos are a godsend for the DIY/Tinkerer community, but there’s all sorts of stuff they just can’t do out of the box. Sure, you can add tons of functionality via strap-on boards called “shields”..