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.

The magic lies in Arduino's Modulino nodes, which consist of various sensors and actuators that connect to the UNO R4 WiFi board. The Plug and Make Kit is a complete package to get started.

As a preview of his latest book, Arduino Project Handbook: 25 Practical Projects to Get You Started, Mark Geddes takes us through the project to create a simple Arduino plant monitor. In this project ...