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20251A1: Automatic water timer for drip irrigation with smart rain sensor

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20251A1: Automatic water timer for drip irrigation with smart rain sensor
Photo by Alibaba

Brief Description & Functionality

Drip irrigation is a type of irrigation system where water is delivered slowly and directly to the roots of plants through a network of pipes, tubes, and emitters. A timer can be integrated with the system to automate and optimize watering, making it more efficient, convenient, and water-conserving. A rain sensor is utilized to measure moisture level of the soil based on the rainfall amount. This smart device

  • automatically pauses irrigation when sufficient rain has fallen,
  • adjusts irrigation based on local weather forecasts.
  • prevents overwatering and conserves water.
  • They can be integrated with IoT devices for real-time monitoring and control.
  • They are cheap and ideal for gardens, greenhouses, and farms as they maintain a consistent watering routine reducing the human effort and care.

Typically resistive or capacitive type rain sensors are used for detecting the moisture level of the soil. The resistive type sensors measure the drop in resistance when rain bridges the metal contacts (see the figure below).

Image source: how2electronics

A capacitive type rain sensor measures change in dielectric constant when water is present. The capacitance of the rain sensitive area increases in wet condition. The schematic of the capacitive type rain sensor is shown below.

Image source: electronic specifier

The soil moisture sensor probe is inserted into the ground. It sends data to the microcontroller. A flow rate sensor for the irrigation line also sends the flow rate data to the microcontroller. The microcontroller is configured to activate a solenoid valve connected to the irrigation line, thereby watering the plants via a relay. The schematic of an IoT-enabled drip irrigation system is shown below. It sends data to a mobile app for monitoring and scheduling the irrigation routine if required.

Image source: IoT journal

You can refer to this video to understand how the irrigation control valve works.

Market Survey

Pinolex Drip Irrigation Kit Digital Water Timer Controller for Home Garden Plants

Useful Resources

Automatic Watering System using Soil Moisture Sensor and RTC timer with Arduino

Skills Required

  1. Arduino programming
  2. ESP32 programming
  3. Circuit simulation
  4. PCB design
  5. PCB milling
  6. Manual soldering
  7. SMT soldering
  8. Electronic testing
  9. Sheet cutting
  10. Sheet bending
  11. CAD modelling
  12. 3D printing (FDM)