Building an Automated Irrigation System for Your Garden with ESP32 and MQTT

10.12.2024 - Engine: Gemini

Building a Garden Irrigation System with ESP32 and MQTT

Components Required

• ESP32 microcontroller
• Soil Moisture Sensor
• Relay board
• Solenoid Valves
• Water Pump
• MQTT Server

Steps

1. Connect the Components

• Connect the Soil Moisture Sensor to an analog input pin on the ESP32.
• Connect the Relay board to a digital output pin on the ESP32.
• Connect the Solenoid Valves to the Relay board.
• Connect the Water Pump to the Solenoid Valves.

2. Install Software

• Install Arduino IDE.
• Download the ESP32 board definition to Arduino IDE.
• Install the following libraries:
  • PubSubClient (for MQTT communication)
  • Adafruit Unified Sensor (for Soil Moisture Sensor)

3. Write the Code

• Create a new Arduino project.
• Write the following code:

#include <PubSubClient.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_DHT.h>

const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";
const char* mqttServer = "YOUR_MQTT_SERVER";
const int mqttPort = 1883;
const char* topic = "/garden/irrigation";

DHT dht(SOIL_MOISTURE_SENSOR_PIN, DHT11);

// Setup MQTT Client
WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(9600);
  dht.begin();

  // Connect to WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }

  // Connect to MQTT server
  client.setServer(mqttServer, mqttPort);
  client.connect("garden_irrigation");

  // Publish MQTT message
  client.publish(topic, "online");
}

void loop() {
  // Read Soil Moisture Sensor
  float humidity = dht.getHumidity();

  // Check if Irrigation is needed
  if (humidity < 30) {
    // Open Solenoid Valve
    digitalWrite(RELAY_PIN, HIGH);
  } else {
    // Close Solenoid Valve
    digitalWrite(RELAY_PIN, LOW);
  }

  // Send data to MQTT server
  client.publish(topic, String(humidity).c_str());
  delay(5000);
}

4. Upload Code and Configure MQTT Server

• Upload the code to the ESP32 board.
• Configure your MQTT server to subscribe to the topic /garden/irrigation.

5. Testing the System

• Start the system and wait for the ESP32 to connect to WiFi and establish connection to MQTT server.
• Check your MQTT server for messages with moisture level and irrigation status.

Notes

• Make sure your Soil Moisture Sensor is rated for outdoor use.
• Use a relay that has enough switching capacity for your Solenoid Valves.
• The moisture and irrigation interval settings can be adjusted based on plant type and environment.