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 ...

Planning another Arduino build? If you’re just doing something simple like switching a relay or powering a LED, you might want to think about the Digispark. It’s a very small ATtiny-bas… ...

An Arduino is by no means expensive, but that still doesn't mean that it suits your needs right out of the box. If you want to make your own custom board, Make shows you how in a three-part series.