You can buy the full-fledged gadget which works out of the box here:
https://wemakethings.net/chirp/
This extension is an easier access to the ingenious humidity sensor through the Micro:bit micro controller.
MIT
All extremely self-explanatory: chirp.getHumidity()
, chirp.getTemperature()
, chirp.getLightLevel()
, chirp.isDry()
- for PXT/microbit