Moderator: igrr
With all good comments and encouragement I am thinking about expanding this project. Maybe with MQTT to integrate with openHAB? This would show how to add ready to use user interface for an IOT project.
Krzysztof
However.. I have written a sous-vide machine.. and it looks (from your graph) that you might be looking for this.
https://github.com/br3ttb/Arduino-PID-Library/
This lib is great. Takes some getting used to, to figure it out. See here for https://learn.adafruit.com/sous-vide-po ... /sous-vide.
Now, with PID you would end up at a steady state humidity, and not the saw toothed profile you showed. It does work very well for temp. I see no reason why this would not work for your humidity. And I'd be very interested to see it work.
That picture is my sous-vide machine reaching equilibrium. This is all run on the ESP8266. The little blip is where I put the food in the cooker.