Description

Specification Details
Sensing principle Measures electrical resistance between two soil-contact electrodes
Operating voltage Typically 3.3–5 V DC
Comparator LM393-type comparator
Analog output — AO Voltage that varies with soil conductivity; read using a microcontroller ADC
Digital output — DO HIGH/LOW signal indicating whether the adjustable threshold is crossed
Threshold adjustment Onboard trimmer potentiometer
Board connections VCC, GND, AO and DO
Probe connection Two-wire connection to the interface board
Indicators Power and threshold-status LEDs
Probe construction Exposed conductive tracks on a fork-shaped PCB
Measurement range Relative dry-to-wet indication
Accuracy No verified percentage-moisture accuracy for this unit
Calibration Establish dry and wet reference readings for the soil being monitored
Applications Automatic irrigation, plant monitoring and educational projects