Soil Moisture Sensor Circuit Diagram. In the previous circuits of moisture sensors like plant soil moisture tester circuit or moisture sensor alarm. All the 16 pins of the pcf8574 driver module are connected with the lcd pins.
The resistor r2 is a potentiometer to adjust the level on which you want to make the led on. Soil moisture sensor circuit diagram. As soil moisture sensor simply acts as two conducting plates.
This soil moisture detector probe is homemade and built using general purpose pcb perf board.
In this circuit we have used an npn transistor to detect soil moisture. All the 16 pins of the pcf8574 driver module are connected with the lcd pins. Using only a transistor led and resistor this simple soil moisture sensor circuit can be used to check the humidity level of materials like soil paper etc. We can use insulation removed copper wires as sensor here or you can use conducting material nail as a moisture detecting sensor.
