Your 3-button garage remote is built to do far more than raise and lower a single garage door. With a little setup, those extra keys can control multiple doors, gates, lights and even security ...

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 ...