Temp, Humidity CO2 sensor and library.

apparently your code always return 2. (Fahrenheit is a 0.2Celsius converted)

I peeked into the library and saw that there are open ends e.g. in the request function (which is at the core)

I have attached a datasheet with another Arduino program, you might give that a try.

AN128- Cozir_Arduino.pdf (106 KB)