These days, most of us have a smartphone. They are so commonplace that we rarely stop to consider how amazing they truly are.

An Arduino is a microcontroller — a single board designed to control something and perform a specific task. Unlike a Raspberry Pi, you won't find anything resembling an operating system here ...

As many Arduino enthusiasts will tell you, they have a million ideas for projects but haven't completed nearly as many as they want. Here are some of the best Arduino projects we have found.