FC-28 Soil Moisture Sensor Module


FC-28 soil moisture sensor is a soil hygrometric transducer that can read the amount of moisture present in the soil surrounding it. The module uses the two probes to pass current through the soil, and then it reads that resistance to get the moisture level. More water makes the soil conduct electricity more easily (less resistance), while dry soil conducts electricity poorly (more resistance). FC-28 offer enhanced protection features such as ESD protection and under voltage protection feature.

FC-28 moisture sensor probes are coated with an immersion gold that protects the Nickel probes from oxidation. These two probes are used to pass the current through the soil and then the sensor reads the resistance to get the moisture values. The sensing radius of the module depends upon the design complexity of the module itself, A satellite-based passive microwave sensor will cover a very wide area of ground, while cheap Chinese hobby sensors can cover only 20-30 cm of land. The module is compatible with a wide array of microcontrollers and allows enhanced interface ability over a wide range of platforms.


FC-28 Key Features

  • Digital Output Threshold Adjust Potentiometer
  • Power and Digital Output Indicator LEDs
  • Analog and Digital outputs
  • Mounting hole for easy installation
  • Easy to use with Microcontrollers or even with normal Digital/Analog IC
  • Small, cheap, and easily available
  • ESD protection
  • Undervoltage Protection

FC-28 Soil Moisture Sensor Pinout

Pin NamePin No.Description
VCC1The Vcc pin powers the module, typically with +5V
GND2Power Supply Ground
DO3Digital Out Pin for Digital Output
AO4Analog Out Pin for Analog Output


  • Operating Voltage: 3.3V to 5V DC
  • Operating Current: 15mA
  • Output Digital – 0V to 5V, Adjustable trigger level from preset
  • Output Analog – 0V to 5V based on infrared radiation from fire flame falling on the sensor
  • LEDs indicating output and power
  • PCB Size: 3.2cm x 1.4cm
  • LM393 based design


  • Usually used to measure or estimate the amount of water in the soil
  • Used to design sophisticated irrigation systems in order to aid and yield better crops.
  • Utilized to help irrigators and agricultural researchers in determining what is happening in the root zone of a crop/vegetation.

Datasheet FC-28

You can download the datasheet for the FC-28 Soil Moisture Sensor Module by clicking the link given below:

See Also: CD4059 Program Divide-by-N Counter | GY-NEO6MV2 Flight Control GPS Module | MPU6050 Gyrometer And Accelerometer Module