Building a Smart Irrigation System with NodeMCU ESP8266

Circuit Connection:

1. Connect the Soil Moisture Sensor:

• Connect the VCC pin of the sensor to the 3.3V pin on the NodeMCU.
• Connect the GND pin of the sensor to the GND pin on the NodeMCU.
• Connect the A0 pin of the sensor to the A0 pin on the NodeMCU.

2. Connect the Relay Module:

• Connect the VCC pin of the relay module to the 3.3V pin on the NodeMCU.
• Connect the GND pin of the relay module to the GND pin on the NodeMCU.
• Connect the IN1 pin of the relay module to a digital pin (e.g., D1) on the NodeMCU.

3. Connect the Water Pump:

• Connect the positive terminal of the water pump to the common (COM) terminal of the relay.
• Connect the negative terminal of the water pump to the normally open (NO) terminal of the relay.

Programming:

Write a program in Arduino IDE using the ESP8266 board support package. Utilize libraries for reading the soil moisture sensor and controlling the relay module.

#include <ESP8266WiFi.h>

// WiFi credentials

const char* ssid = "your_SSID";

const char* password = "your_PASSWORD";

// Pin definitions

const int moistureSensorPin = A0;

const int relayPin = D1;

// Moisture threshold (adjust as needed)

const int moistureThreshold = 500;

void setup() {

Serial.begin(115200);

pinMode(relayPin, OUTPUT);

digitalWrite(relayPin, LOW); // Ensure relay is off initially

// Connect to WiFi

WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {

delay(500);

Serial.print(".");

}

Serial.println("WiFi connected");

}

void loop() {

int moistureValue = analogRead(moistureSensorPin);

Serial.print("Moisture: ");

Serial.println(moistureValue);

if (moistureValue < moistureThreshold) {

Serial.println("Soil is dry. Turning on pump.");

digitalWrite(relayPin, HIGH); // Turn on relay (activate pump)

delay(5000); // Run pump for 5 seconds (adjust as needed)

digitalWrite(relayPin, LOW); // Turn off relay

}

delay(60000); // Check moisture every minute (adjust as needed)

}

Optional Features:

• Implement a real-time clock (RTC) module for scheduling irrigation times.
• Add a water level sensor to monitor water reservoir levels.
• Integrate with a mobile app for remote monitoring and control.

Conclusion:

Building a Smart Irrigation System with the NodeMCU ESP8266 demonstrates the practical application of IoT technology in agriculture. This project provides a foundation for developing more sophisticated smart farming solutions and showcases the versatility of the ESP8266 microcontroller in IoT projects.