A little project to track the humidity (and the temperature) inside my appartment to know when I should open a window while drying my laundry.
Humidity and temperature are tracked with a Raspberry Pi and a DHT22 sensor and plotted via Thingspeak API. Like that, I can check my appartments temperature and humidity whenever I want. Additionally, I send notifications to my smartphone via IFTTT if the humidity is too high or the temperature too high or too low.
For a detailed documentation on how to create your own humidity tracker, check out the Wiki!