Smart Irrigation System Using Arduino for Automatic Plant Watering

Smart Irrigation System Using Arduino for Automatic Plant Watering

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  PROJECT WORK Smart IrrigationSystem Using Arduino UNO, Soil Moisture Sensor, Relay Module & DC Water Pump Subject Vocational Education Project Home Automation (Drip Irrigation ) Topic Smart Irrigation System (Automatic Plant Watering) 1. Aim of the Project To design and build a Smart Irrigation System that automatically waters a plant when the soil becomes dry, using an Arduino UNO, a soil moisture sensor, a relay module and a DC water pump. 2. Introduction Plants need the right amount of water to grow well. Watering them by hand every day can be difficult, and sometimes we forget or give too much or too little water. A Smart Irrigation System solves this problem by using a sensor to check the moisture in the soil and automatically switching a water pump ON when the soil is dry, and OFF when the soil has enough water. This saves water, saves time, and keeps the plant healthy even if no one is available to water it. 3. Components Required S.No Component Quantity Function 1 Arduino UNO 1 Main controller board that runs the program 2 Soil Moisture Sensor 1 Measures how wet or dry the soil is 3 Relay Module 1 Acts as an electronic switch to turn the pump ON/OFF 4 Water Pump (DC Motor) 1 Pumps water to the plant when switched on 5 Connecting Wires As needed Connect all the components together 6 Power Supply / USB Cable 1 Powers the Arduino UNO 4. Circuit Diagram
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  The soil moisturesensor, relay module and water pump are connected to the Arduino UNO as shown below: Fig 1: Circuit connection of Smart Irrigation System 5. Pin Connections Component Pin Connected to Arduino Pin Soil Moisture Sensor VCC / GND / A0 5V / GND / Analog Pin A0 Relay Module VCC / GND / IN 5V / GND / Digital Pin D7 Water Pump + / - Relay Module Output (NO terminal) 6. Working Principle 1. The soil moisture sensor's probes are inserted into the soil near the plant. 2. The sensor measures the moisture level in the soil and sends this value to the Arduino UNO. 3. The Arduino compares the sensor value with a fixed threshold value set in the program. 4. If the soil is dry (moisture value is high), the Arduino sends a signal to the relay module to switch ON. 5. The relay acts like an automatic switch and turns ON the DC water pump, which starts watering the plant. 6. Once the soil becomes sufficiently wet (moisture value falls below the threshold), the Arduino turns the relay OFF, which stops the pump. 7. This cycle keeps repeating, so the plant is watered automatically only when it is needed. 7. Sample Arduino Code int sensorPin = A0; // Soil moisture sensor connected to A0 int relayPin = 7; // Relay module connected to pin 7 int threshold = 500; // Moisture level to compare void setup() { pinMode(relayPin, OUTPUT); Serial.begin(9600);
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  } void loop() { intmoistureValue = analogRead(sensorPin); Serial.println(moistureValue); if (moistureValue > threshold) { // Soil is dry -> turn pump ON digitalWrite(relayPin, HIGH); } else { // Soil is wet -> turn pump OFF digitalWrite(relayPin, LOW); } delay(1000); } 8. Applications • Watering garden plants and kitchen gardens automatically. • Used in agriculture fields to save water and manual effort. • Useful in greenhouses and nurseries. • Helps water plants when the owner is away or on vacation. 9. Conclusion The Smart Irrigation System successfully waters the plant automatically based on soil moisture, without any human help. This project shows how sensors, microcontrollers and simple electronics can be combined to solve a real-life problem, save water, and make gardening easier and smarter.