YL-69 (FC-28) Soil Moisture Sensor Module with LM393 Comparator for Arduino, ESP32 and STM32

A ready-made kit for measuring the moisture level of soil and ground, widely used in automatic irrigation systems, smart greenhouses and educational projects with Arduino. Two types of outputs (AO / DO): The analog output (AO) allows smooth tracking of the degree of soil drying (from dry to wet), while the digital output (DO) outputs a logic signal 0/1 when a set level is reached. Convenient threshold adjustment: A trimmer potentiometer allows precise adjustment of the switching threshold of the digital output (for example, to automatically start a pump when the soil becomes critically dry). Complete set: The kit includes the YL-69 immersion probe, the FC-28 signal processing board and Dupont connection wires. Features Sensor type — Resistive soil moisture sensor (two-electrode YL-69 probe) Processing board — FC-28 module based on the LM393 comparator Output signals — Analog (AO) and digital (DO) Threshold adjustment — Built-in trimmer potentiometer (for the DO output) Supply voltage — 3.3 V – 5.0 V DC Indication — Power LED (PWR) and digital output status LED (DO-LED) Probe coating — Nickel plating against corrosion Dimensions — Immersion probe: 60 × 20 mm, control board: 30 × 16 mm