The Soil Moisture Sensor / Soil Hygrometer Module is a simple and low-cost sensor used to measure the water content (moisture level) in soil. It is commonly used in smart agriculture, gardening, and automated plant watering systems with Arduino, ESP32, or Raspberry Pi. 🔹 Components of the Module: Probes (Soil Sensor Fork) – two exposed conductive traces that go into the soil. When soil is wet, it conducts electricity better (low resistance). When soil is dry, it has poor conductivity (high resistance). Driver/Comparator Board (LM393 chip) – converts the signal from the probes into: Analog Output (AO): gives variable voltage (0–5V) depending on soil moisture. Digital Output (DO): HIGH/LOW signal based on a threshold set by the onboard potentiometer. 🔹 Specifications: Operating Voltage: 3.3V – 5V DC Current Consumption: ~10 mA Output Types: Analog Output (AO): 0–5V, proportional to soil moisture Digital Output (DO): 0 or 1, based on threshold set by potentiometer Onboard Potentiometer: adjusts sensitivity of the digital output Indicator LEDs: Power (PWR) & Digital output status (DO) 🔹 How It Works: Insert the probes into the soil near plant roots. Dry soil → High resistance → Lower analog voltage → Digital output = LOW (depending on threshold). Wet soil → Low resistance → Higher analog voltage → Digital output = HIGH. 🔹 Applications: Automatic plant watering systems Smart irrigation projects Soil moisture monitoring Greenhouse automation 🔹 Wiring with Arduino: VCC → 5V GND → GND AO → A0 (Analog pin) DO → D2 (or any digital pin)