Before I start talking about this really cool thing called Arduino (Italian for "good friend"), let me say a few things about the fascinating subject of physical computing. Physical computing has been ...

In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board, one 1K and one 10K resistors, 1 BC547 transistor, one 6V or 12V relay, one 1N4007 diode and a 12V fan ...