Lately I get a lot of small packages with hardware modules from China. They take between 2 and 6 weeks to arrive. Some of the parts I’m waiting for are needed to continue my current project(s). Because of this I often check the mailbox and it is really annoying to open an empty mailbox. Therefore, I was building the mailbox notification. Hardware I checked the WIFI inside the mailbox and it was not existing so I couldn’t just use a simple ESP8266 like the Wemos D1 Mini and a battery to get it to...