reef-pi 3.3 onwards we have file driver which can be used to prototype /test any new driver. Just write your sensor value into a file and reef-pi will read that file and treat the value as analog input which can be hooked up to a ph module for controlling equipment etc. for example one can use circuit python based adafruit gas sensor code to maintain a file and write the sensor value there and then configure reef-pi with that file. This will allow controlling a air purifier with gas sensor data using reef-piFantastic - I`ve got a couple of bits on order but before I share details i want to test it in my DT and QT. It could be a total flake so i'd rather do some initial testing before opening it up to peer review (like a proper scientific study).