Automating your home is an awesome endeavor — but playing with mains AC can be risky business if you don’t know what you’re doing. So why not play it safe and make use of your light switch?
Admittedly, it wasn’t because [Tyler Bletsch] didn’t want to mess around with AC directly, but rather out of necessity. You see, he just moved into a new office and his “smart” air conditioner… doesn’t turn itself off at night.
There’s a remote control to set the target temperature, but the unit isn’t smart enough to turn off at night. Instead, there’s a physical wall switch so you can turn it off with your actual physical hands, like a barbarian.
Refusing to be a barbarian (and to stay at work late), he decided to simplify the problem by building a servo driven light switch plate. It’s not the prettiest — but it does the trick.
He designed the bracket in Thingiverse to mount a standard 9g servo motor to do the flipping. An Arduino Nano controls it, but since you only need one output pin to run the servo, you could easily use an ESP8266. He went ahead and added a small OLED screen and a few buttons too — he’s using this as a timer to control the A/C unit, but it’s begging for a web dashboard, right?
Alternatively, you can mess with AC directly with this hack using a Raspberry Pi — but you should probably own the place your planning on “upgrading”.