Overview:

This IoT-based project is designed to automate the watering of plants by monitoring soil moisture and environmental conditions in real time. It ensures optimal soil hydration, reducing manual effort and promoting healthier plant growth.

🧱 Tech Stack

• IoT Hardware:

  • ESP32 Microcontroller – Serves as the central controller for sensor data processing and cloud communication.
  • DHT22 Sensor – Monitors ambient temperature and humidity for environmental awareness.
  • Soil Moisture Sensor – Detects the moisture level in the soil to determine watering needs.
  • Motor Pump – Automatically activated to deliver water when the soil is detected as dry.

• Cloud Platform:

  • Arduino IoT Cloud – Used for remote monitoring and control. It syncs real-time sensor data and allows remote toggling and automation through dashboards.

• Control Logic:

  When the soil moisture sensor detects dryness below a defined threshold, the ESP32 triggers the motor pump to water the plant. Watering continues until the sensor reads the desired moisture level, after which the pump is turned off automatically.

Arduino Cloud Design

Casing Design:

Prototype With 3D Printed Casing

Arduino IDE Code:

#include "thingProperties.h"
#include <DHT.h>

#define relayPin 12
#define moisturePin A0
#define DHTPIN 2
#define DHTTYPE DHT11
#define debugPin 4

#define wet 210
#define dry 510

DHT dht(DHTPIN, DHTTYPE);

unsigned long lastSensorRead = 0;
const unsigned long sensorReadInterval = 2000; // Read sensors every 2 seconds
const unsigned long pumpOnDuration = 5000; // Minimum pump on duration in milliseconds

bool pumpState = false;
unsigned long pumpActivatedTime = 0;

void setup() {
  Serial.begin(9600);
  delay(1500);

  pinMode(relayPin, OUTPUT);
  pinMode(debugPin, INPUT);
  digitalWrite(relayPin, HIGH);

  dht.begin();

  // Initialize properties
  initProperties();

  // Connect to Arduino IoT Cloud
  ArduinoCloud.begin(ArduinoIoTPreferredConnection);

  // Set debug message level
  setDebugMessageLevel(4);
  ArduinoCloud.printDebugInfo();

  Serial.print("Connecting to WiFi: ");
  Serial.println(SSID);

  // Wait for WiFi to connect
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }

  Serial.println();
  Serial.print("Connected to WiFi, IP address: ");
  Serial.println(WiFi.localIP());

  // Wait for the IoT Cloud connection
  Serial.println("Connecting to Arduino IoT Cloud...");
  while (ArduinoCloud.connected() != 1) {
    ArduinoCloud.update();
    delay(1000);
    Serial.print(".");
  }
  Serial.println("Connected to Arduino IoT Cloud");
}

void loop() {
  ArduinoCloud.update();

  // Only read sensor values and control the pump if connected to the IoT Cloud
  if (ArduinoCloud.connected() && (millis() - lastSensorRead >= sensorReadInterval)) {
    lastSensorRead = millis();

    sensorValue = analogRead(moisturePin);
    int moisturePercent = map(sensorValue, dry, wet, 0, 100);

    temperature = dht.readTemperature();
    humidity = dht.readHumidity();

    if (isnan(temperature) || isnan(humidity)) {
      Serial.println("Failed to read from DHT sensor!");
      return;
    }

    Serial.print("Moisture: ");
    Serial.print(moisturePercent);
    Serial.print("%, Temperature: ");
    Serial.print(temperature);
    Serial.print("°C, Humidity: ");
    Serial.print(humidity);
    Serial.println("%");

    // Automatic pump control based on soil moisture
    if ((moisturePercent < 30 || digitalRead(debugPin) == HIGH) && !pumpState) { // Adjust this threshold based on your needs
      // Turn pump on
      digitalWrite(relayPin, LOW);
      relay = true;
      pumpState = true;
      pumpActivatedTime = millis();

      if (digitalRead(debugPin) == HIGH) {
        Serial.println("DebugPin Triggered");
      }
    } else if ((moisturePercent > 40 && pumpState) && (millis() - pumpActivatedTime >= pumpOnDuration)) { // Adjust this threshold based on your needs
      // Turn pump off
      digitalWrite(relayPin, HIGH);
      relay = false;
      pumpState = false;
    }
  }
}

// Arduino IoT Cloud callback function
void onRelayChange() {
  if (relay) {
    digitalWrite(relayPin, LOW);
  } else {
    digitalWrite(relayPin, HIGH);
  }
}

void onSensorChange() {
  // Placeholder for sensor change logic if needed
}