This sensor module detects and/or monitor moisture level in soil. You can use this sensor in an automatic plant watering system.
The sensor itself is a probing plate with two prongs and nickel plating on both sides. The plate is to be connected to the 2 pin header on the comparator board.
The board has a LM393 voltage comparator chip to give out output and a potentiometer for sensor sensitivity adjustment. The working voltage of this module is between 3.3V and 5V. There are 4 pins for output marked as VCC, Ground and DO and AO.
The Digital Output (DO) pin gives 2-state digital output and you can read it easily with any microcontroller/microprocessor. With a certain treshold, when the sensor detects moisture, it gives output LOW. When no moisture detected, it gives output HIGH. Adjust the treshold by turning the potentiometer. You could also connect the output pin directly to a buzzer for audible alarm.
For more precise moisture level reading, there is an Analog Output (AO) pin that you can connect to an Analog-to-Digital converter.
There are 2 status indicator LEDs on board. The one marked as PWR-LED is to tell us the power is connected and the one marked as DO-LED is to indicate moisture detection. There are mounting holes on the PCB so that you can fix the position of this module.
Jumper wires connecting the probe and the comparator board is included.
Technical details:
Operating voltage: 3.3V - 5V
Red LED (PWR-LED) - operational status indicator
Green LED (DO-LED) - digital output status indicator
DO Green LED ON, output LOW - moisture detected
DO Green LED OFF, output HIGH - no moisture detected
A potentiometer that can be used to adjust treshold
