HiGrow accuracy or missing calibration

[ro85ac]

I have 4 HiGrow board and all have the same issue:

• If I put Higrow in a glass of water the Soil Value is always around 65%, when the expected value should be 100%
• If I take it out of the water the Soil Value is 22%, when the expected value should be 0% @LilyGO @lewisxhe Is the soil sensor accuracy low or am I missing a calibration?

As a note: I made the same test with Xiaomi Soil Sensor and the values are correct. https://www.aliexpress.com/item/32848400991.html

[ro85ac]

After digging more I found that you calculate the soil moisture using method map from WMath.cpp long map(long x, long in_min, long in_max, long out_min, long out_max)

And the actual code is: map(soil, 0, 4095, 100, 0);

@LilyGO @lewisxhe Why did you send the parameters 0 and 4095 when the actual values read by the sensor are ~1475 (min) and ~3280 (max)?

[LilyGO]

After digging more I found that you calculate the soil moisture using method map from WMath.cpp long map(long x, long in_min, long in_max, long out_min, long out_max)

And the actual code is: map(soil, 0, 4095, 100, 0);

@LilyGO @lewisxhe Why did you send the parameters 0 and 4095 when the actual values read by the sensor are ~1475 (min) and ~3280 (max)?

Because the soil medium is different, it is impossible to do a unified calibration.