I have bought some of your ESP32S2 Soil Moisture Sensors and I have flashed the example source code to them, which is running, but I am having issues with the sensor for moisture/humidity.
The channel width is set to 13bit, so it such be able to produce values between 0 and 8191.
In reality it only produce values in the range 2950 (submerged in water) to 3150 (dry and floating in the air).
Those values would have been fine, if they were precise with little fluctuations, but that is not the case.
The real range is more like 3000 to 3100 and the values can fluctuate with ±50, which means I can barely differentiate the 2 outer limit values from each other and anything in between is just a wild guess.
I have tried playing around with the channel ADC channel attentuation, but that just seems to add or subtract a fixed value to all readings.
I can not seem to use another ADC channel width than 13bits without getting an error and I do not really think that would help anyway, due to the fluctuations.
I am not enough into the theroy on the capacity sensoring, so what can be done to increase the precision of the reading and maybe also increase usage of the available resolution?