1. This is a simple water sensor can be used to detect soil moisture when the soil moisture deficit module outputs a high level, and vice versa output low. Use this sensor produced an automatic plant waterer device, so that the plants in your garden without people to manage.
2. Sensitivity adjustable the blue digital potentiometer adjustment (Figure)
3. Operating voltage 3.3V-5V
4. Module dual output mode, digital output, analog output more accurate.
5. With fixed bolt hole for easy installation
6. PCB size: 3cm x 1.6cm
7. Power indicator (red) and digital switching output indicator (green)
8. Comparator LM393 chip, stable
Interface Description (4-wire)
1. VCC: 5V
2. GND: GND
3. DO: digital output interface (0 and 1)
4. AO: Analog Output Interface
Instructions for use:
1. Soil moisture module is most sensitive to the ambient humidity is generally used to detect the moisture content of the soil.
2. Module to reach the threshold value is set in the soil moisture, DO port output high, when the the soil humidity exceeds a set threshold value, the module D0 output low;
3. The digital output D0 can be connected directly with the microcontroller to detect high and low by the microcontroller to detect soil moisture;
4. The digital outputs DO shop relay module can directly drive the buzzer module, which can form a soil moisture alarm equipment;
5. Analog output AO and AD module connected through the AD converter, you can get more precise values of soil moisture
Schematic : Soil Moisture Sensor + Amplifier
Reference : smart-prototyping.com