In this project I would like to make a smart thermostat, which will later can control an home automation system. My requirement is to have touch screen, wifi, and a good sensor for measure the temperature 0.1 celsius precision.
I already bought the display, which is an MCUfriends 3.5" touch screen. It is a nice display, and has a very good library in arduino IDE. The screen need a lot of I/O pin on the arduino, so I choosed an arduino mega, because I will have to connect a relay and a wifi modul to it. Furthere more I needed more space for code in the memory.
The sensor is a HTU21, which has good resolution and can measure temperature and humidity as well.
The wifi capability will need because I want pull data from the web for some outside parameters, like the outside temperature, humidity and maybe display what is the wheater looks like at the moment.
I would like to log some parameters, like how many minutes/ houres went the heating system in my appartment, and after I would like to display those values on the screen in a form of a graph. Like I would like to make graphs daily, weekly and montly form, so I can see how much will I have to pay for heating.