For all the home hobbyists, you knew that dealing with microcontrollers is a fun thing. Once you have been hooked with it, there was no turning back. Do you know that a microcontroller’s GPIO (General-purpose input/output) pins cannot handle higher power requirements? An LED was easy enough, but how about the large power items such as light bulbs, toaster ovens or blenders that required more circuitry? In this case, a relay is wanted in this situation. However, building a 5V controllable power outlet can be handy for many applications; thus a relay is a perfect choice for this project! For your information, a relay is a large mechanical switch, where the switch is toggled on or off by energizing a coil constantly. By applying the relay in the project, it will ensure your safety. Let’s take an example. If you have 120VAC running through the paddles, you don’t have to worry that 120VAC will sneak back into and vaporise your microcontroller connected to the coil, as the paddles are capable of carrying substantial currents! Furthermore, you can use the relay to control a DC motor or an AC lamp if you want to.