Smart Irrigation System Using Sensors - Electronic Engineering Guide
1. Introduction
A Smart Irrigation System using sensors automates water supply based on soil moisture levels. It conserves water and increases crop yield by ensuring optimal irrigation timing using real-time sensor data.
2. Objectives
• To automate irrigation using soil moisture sensing.
• To reduce water wastage and improve agricultural efficiency.
• To optionally include remote monitoring or control features.
3. Components Required
• Arduino Uno or any compatible microcontroller
• Soil moisture sensor (capacitive or resistive type)
• Relay module or MOSFET switch
• Water pump (DC or AC)
• Power supply (Battery or Adapter)
• Jumper wires, resistors, breadboard
• Optional: ESP8266 or GSM module for remote monitoring
• LCD or OLED display (optional)
4. System Overview
The system reads data from a soil moisture sensor and controls the water pump through a relay or MOSFET. When the soil is dry (below threshold moisture level), the pump is turned on; otherwise, it remains off. Optional modules can send updates via Wi-Fi or GSM.
5. Sensor and Microcontroller Integration
The soil moisture sensor outputs an analog signal proportional to the moisture level. This is read by the Arduino's analog input. Based on this value, a digital output pin activates the relay to control the pump.
6. Circuit Design and Operation
The sensor is powered by 5V and GND from the Arduino. Its
signal pin goes to A0.
The relay module is connected to a digital pin and controls the water pump’s
power.
• Soil Moisture Sensor: VCC → 5V, GND → GND, OUT → A0
• Relay Module: IN → D7 (or any digital pin), VCC → 5V, GND → GND
7. Software and Code Explanation
Arduino IDE is used for programming. A threshold value is
set for moisture level to activate the pump.
Example Code Snippet:
int sensorPin = A0;
int relayPin = 7;
int threshold = 400;
void setup() {
pinMode(relayPin, OUTPUT);
Serial.begin(9600);
}
void loop() {
int moisture = analogRead(sensorPin);
Serial.println(moisture);
if (moisture < threshold) {
digitalWrite(relayPin, HIGH); // Pump
ON
} else {
digitalWrite(relayPin, LOW); // Pump
OFF
}
delay(1000);
}
8. Applications
• Agricultural irrigation systems
• Greenhouse and nursery management
• Lawns, gardens, and smart homes
• Water conservation projects
9. Challenges and Future Enhancements
• Sensor corrosion due to prolonged soil contact.
• Inconsistent readings due to soil composition.
• Can be improved with wireless connectivity for IoT-based monitoring.
• Use multiple sensors for large fields.
• Integrate rain detection to prevent overwatering.
10. Conclusion
Smart irrigation using sensors is an efficient and economical solution to automate water delivery. This system promotes sustainable agriculture and can be scaled with advanced features like weather forecasting and remote control.