I am using Rev 2.2 of the hardware for this soil moisture sensor. The wiki and the sample source code, does not mention how to calculate relative humidity of the soil from reading the soil moisture sensor.
Can you please provide how to get a relative humidity value given the values returned by reading the PIN_SOIL (I get values in the 565 area at 22.5 deg celcius just after dousing the soil with water).
Perhaps an update to the sample source code and wiki would help. The only values shown on the wiki are for the rev 1 soil sensor showing 640-860.