Background
In a previous post, I wrote about building a presence sensor to automatically turn my bedroom lights on and off (smart bulbs connected to Home Assistant). However, I still had to solve the wall switch problem.
Problem
A normal light switch interrupts mains power to the bulb. This is really bad for smart bulbs. They need continuous power to stay connected to the network (WiFi, in my case), which allows them respond to commands. So every time the wall switch is flipped, it cuts power to the bulb, breaking the whole smart home workflow. The fix was to tell people "don't touch the switch!", but that gets old, and you're fighting against muscle memory.
What's more, when the presence sensor doesn't work, it really sucks to hunt for your phone, just to SWITCH ON A LIGHT. In those moments, it truly feels like an Internet of Shit. My first attempt at fixing this was to build a "control center": I mounted a cheap tablet to the wall near the switch, and opened the Home Assistant page in a browser. This didn't work well; the tablet was too slow, ran out of battery often, and had flaky voice controls.
