When cleaning the workshop I found a AI thinker board with a microcontroller, ESP8266, relay and DCH11. Just something I was looking for to make a central heating regulator.
Anyway – some googling lead me to a great page with detailed info on how to hack the board to use ESP8266.
You need to have a USB to TTL converter with 3V3 voltage. Luckily I have an FT232 3V3 cable, but it didn’t work on Mac OSX Sonoma (14.2.1) and this leads to another blog post.