Looking for practical Arduino projects? This guide shows how to control a relay from your smartphone using an Arduino Uno — ...

Every so often we run across something in the Hackaday tip line that sends us scurrying to Google, trying to source a component, part, or assembly. The ESP8266 WiFi module is the latest, made inter… ...

He ran it through a resistor and a Zener diode to lower the voltage to something the Arduino can handle. Once the Arduino detects a signal, it uses an ESP8266 WiFi module to send an email.