Looking for practical Arduino projects? This guide shows how to control a relay from your smartphone using an Arduino Uno — either via Bluetooth or Wi-Fi.

Raspberry Pi projects come in all shapes and sizes, and some can even come in handy for the outdoors. If you like hiking, this project might be perfect.

As I've experimented and played with a lot of different sensors, I've discovered that these basic devices can be built for super cheap, and they're incredibly versatile. When you're done using an ...