After many, many years I rediscovered electronics as a hobby in 2015 and started playing around with sensors connected to an Arduino Uno R3 and Raspberry Pi. It was fun to link them with motion detection sensors and switch lamps on and off. One drawback, however, was the pricing of those components, if you want to have quite a few of them connected by WiFi.

This was when I stumbled over the ESP8266 microcontroller. It is very small, really cheap (around 2 Euros if you order in China) and has WiFi built in already. The downside, compared to an Arduino, is that you need to take care of a lot of things on your own:

• Everything runs on 3.3 volts and 5 volts will kill the thing
• You need to get a USB-to-serial converter with 3.3 volt signal level
• Flashing is less convenient, since you need to change jumpers between normal and upload mode
• etc.

But there is a really vibrant community out there and many problems have already been solved. So I will start writing about various aspects of this and look forward to feedback.