Temperature, humidity and barometric pressure showing a comparison to a previous point in time and graphing the trend.

I wanted to get more meaningful information from a basic temperature, humidity and pressure setup and I figured the way to do that was to have data that could be compared to a previous point in time. This is especially true for barometric pressure since whether it is rising or falling is far more useful than just knowing the current pressure alone.

The hardware I used is listed above and it’s all connected in a standard way. I won’t be getting into obtaining basic data from the sensors and sending it to an LCD, I’ll assume you’re past that point. This is more of a code example than a hardware tutorial. If you can get data to or from a DHT22, a BMP280 and a 20x4 LCD you should be good. I’m including a .fzz diagram of the circuit for completeness. It might even be right.

I describe the screens in greater detail below, but the video below shows system startup and then an abbreviated run through the 3 screens of data.”