“Smart” plugs for your home can be a lot of fun, allowing you to create lighting scenes, activate security features, or control other things in your home remotely. If you’re a DIY type, here’s a great option for building and controlling your own Smart Plug with a Circuit Playground Express. The trick is to use a Power Switch Relay power strip, with outlets that can be controlled by pulling a digital I/O pin “high” or “low” with a microcontroller. We like using the Circuit Playground Express, because suddenly there are a myriad of ways to control your outlets using any of the Circuit Playground’s onboard sensors or inputs. Add some creative code using Arduino, Circuit Python or MakeCode, and you’ve got the power to control all kinds of things.
From the guide:
Control All the Things in your house with a Circuit Playground Express and a Power Switch Relay. This little power supply is a toggle-able “Smart Plug” that you can use for all kinds of home automation applications.
It has one plug that’s always on (for powering your Circuit Playground).
The other plugs are where it gets interesting. There are two plugs that are normally OFF and one that is normally ON. Activating the relay with the Circuit Playground turns the “on” plug to OFF, and the two “off” plugs to ON. Simple and elegant, yes?
Where it gets really interesting when you combine this functionality with the inputs and triggers on with the Circuit Playground Express. You can toggle the switches so many ways:
- Move, tilt, or shake the Circuit Playground
- Make a loud sound (like a DIY version of “The Clapper!”)
- A change in ambient light
- A change in ambient temperature
- Capacitive touch pads, and things attached to them
- Circuit Playground’s onboard buttons
You can also create timers or combinations of triggers to toggle the outlets. It’s safe to use with higher voltage devices like lamps or heaters, too. The sky is the limit.
See Erin St. Blaine‘s full tutorial here:
https://learn.adafruit.com/beginner-first-project-power-switch-relay-circuit-playground-smart-plug