What is the simplest way to detect a power outage?

[ogiewon]

And then you can also just monitor the status of an always-on LAN device with no additional hardware required whatsoever. However, this method does rely on your home network...

Simple Power Outage Detector

Have you ever wanted a very simple method to monitor is a certain power circuit has lost power? Perhaps a GFCI circuit with a garage freezer on it? Or maybe you're Hubitat Hub is on UPS, and you'd like to know if the power went out in your house so you can safely shut down your hub before the UPS dies? Whatever the reason, I think I have stumbled upon a very simple, low cost solution. A friend of mine came up with an idea to use a RPi to ping a USB-powered ESP8266 connected to his WiFi netwo…