In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board ... drive the LOAD to the arduino and transistor circuitry! You can use this code example to introduce ...

At points I might do something that might be dangerous because I'm comfortable with some tools or techniques but please always use your common sense and don't try everything you see here.

How it works: The first few lines of the code define program variables ... to where you plugged the PIR sensor and power relay into the Arduino. With your fan unplugged, turn it on and set it ...