I'm working on a project with a soil moisture sensor and need some guidance. The process involves calibrating the meter: I press button A to get the dry value and button B to get the wet value. Everything seems to work fine during calibration, but when I insert the sensor into the soil, the moisture readings fluctuate between 0 and 100. Sometimes it briefly gives a reading in between but quickly drops again. I'm wondering why I'm not getting accurate readings from the sensor once it's in the soil.
2 Answers
It’s common for moisture sensors to behave erratically in the soil if they aren’t properly calibrated or if they're not making good contact with the soil. Make sure the sensor is clean and the connections are secure. Also, try testing it in different types of soil to see if that affects the readings.
Have you checked the raw moisture values? If they jump between your wet and dry values, that could indicate a problem with the sensor's connection or calibration. It might help to directly monitor the raw readings without the mapped output to see what's happening.
I haven't looked at just the raw readings yet. I thought calibration would give me the most reliable results, but maybe I should try that first and see what the raw values actually are.

Thanks for the tips! I’ll check the connections and maybe do a bit of testing in a few different soil types.