Interface Soil Sensor With AVR


Soil sensor measures the water content in the soil. The Soil Sensor is used to measure the volumetric water content of the soil.

  • Soil moisture sensor has two probes through which current passes in soil.
  • Then read the resistance of soil to know the moisture level.
  • Water makes the soil more prone to electric conductivity resulting in less resistance in soil, where on the other hand dry soil has poor electrical conductivity thus more resistance in soil.
  • Using these properties of electricity the sensor is designed.
  • Inside the sensor, there is circuitry for measuring the resistance and converting it into voltage as output.


  • Irrigation controller.
  • Gardening.

Hardware Required

  • Soil Sensor.
  • Atmega16 MicroController.


  • VCC: +5v.
  • Gnd: Gnd.
  • Output: Digital.