[cwassert]

I second this wholeheartedly.

As a toy project I put a raspi with a small screen in my living room that would show the temperature and humidity for the last three days as a graph. It was somewhat of an eye catcher in the living room. The data was always interesting. Even if the humidity did not change much, at the very least you could always see that it was colder during the nights, which told me it was working.

It taught me so many things. The effect of opening the windows short vs. long on temperature and humidity. That the sun shining into my room was way more effective then my heating. How the temperature goes down exponentially when my heating turns off, and how the length of the of/off cycles depend on the temperature outside. Etc.