Could be a genuino BMP280, I dont know. The shop from where I brought usually indicates a brand when it is one and it did not in this case. But indeed, who knows, it might me just an omission.
Is this one:
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I have very bad experience with the libraries for this sensor. It took me days to match one. The Adafruit one didnt work, despite all advises on the internet about what and how to modify. Another one I found on the git didnt even compile.
In my case about this sensor, I had to figure out whether it is about wiring, code or other mistakes. That was very laborious and took a lot of time. Even today I am not quite sure what the problem was. The library that eventually work was a rather unknown one.
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From my history, home thermostats are more tricky than expected.
For instance, in an apartment room I saw the temperature sensor on the kitchen wall, to regulate the dormitory. Of course, it was terrible cold in the dorm, but the owner refused to open the heating because the thermometer showed high temperature in the place where the senor was placed. This is an extreme case and somehow easy to spot. But in another case, the owner was very committed to do whatever needed to heat the room. He ended up however by disconnecting the whole automatic system and go for manual. Neither the seller of the automatic heating system was able to tell what went wrong.
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For real life situation, what I found as reliable is to put 2 thermometers in 2 opposite sides of the room and take care about thermal insulation. Thermal insulation is not only about having the reccomennded thickness of the insulation layer (which I dare to say in some cases is not observed anyway because it looks to much for the constructor to put on :-)) but also about identification of thermal bridges.
I suspect that some "industrial" thermostat solutions are nothing more than hobby well-marketed.
In my opinion, my experience described above may help to decide about design of humidity control, beyond pure technical issues - for which I am not the right person to advise. I pointed to DH22 is an option because it is very simple to handle and code and cheap enough.