Yl-105 Datasheet [patched] -

Based on common implementations of the YL-105 module, here are the standard specifications: Specification Output Type Analog (AO) & Digital (DO) Interface 4-pin (VCC, GND, DO, AO) Comparator LM393 Chip Threshold Adjustment Onboard Potentiometer Dry Soil Output High Analog Value / Digital High Wet Soil Output Low Analog Value / Digital Low Dimensions (Probe) ~60mm x 20mm 3. Module Pinout and Description

Low resistance, allowing more current to pass, resulting in a low analog output value (near in Arduino). yl-105 datasheet

The chip hummed again.