I had three broken rear LED lights on my BMW F25! I found a easy and cheap fix, resolder one resistor on every driver, and they all worked again!
I needed a display for my outdoor temperature sensor which is connected to Home Assistant.
So I built one with a ESP8266, Lolin D1 mini with official OLED shield.
It features a WIFI connected OLED-display, with capabilities to display almost anything from Home Assistant.
I bought a couple of Sonoff S26 Wifi-plugs. These are built with an ESP8266 wifi chip and can be programmed with custom firmware.