I’ve recently found that you can get very cheap SoC computers with wifi already on board. This almost sounds perfect for my custom OpenHAB installation. For instance I use OpenHAB to controll the heating at home but currently the only source for the current temperature is the thermometer right at the radiator, which is (as you might have guessed) not the best spot to measure the current temperature. So I bought some ESP8266 (ESP-01S) and some Shields for it, which already contains voltage regulation and a DHT-11 for measuring temperature and humidity. I’ve cut some old USB wires to power it. I’m curious if those things can be powered with an old powerbank or if I have to use a power adapter.

Example of the assembled unit
Example of the assembled unit

I’m still waiting for the USB device to flash the firmware on those small little ESP-01S. Once it had arrived, my plan is to use Arduino to write some code which measures the current temp./hum. every few minutes and posts (http) it to my OpenHAB server, which then uses the newly added data to tune the heating.

Btw: If anyone has a good idea how to create a housing for these things, please let me know!