ESP8266 Blynk IoT Smart Plant Monitoring System

Introduction

In the modern era of technology-driven solutions, plant care has been revolutionized through the use of smart plant monitoring systems. These systems leverage IoT (Internet of Things) technology to automate, monitor, and manage plant health from anywhere. One of the most accessible and efficient combinations for such projects is the ESP8266 microcontroller paired with the Blynk IoT platform. This setup provides users with a user-friendly, scalable, and highly customizable solution to maintain their garden or indoor plants efficiently.

This guide will walk you through building a comprehensive ESP8266 Blynk IoT Smart Plant Monitoring System, highlighting the essential components, setup process, programming, and enhancements.

Understanding the Core Components

ESP8266 Microcontroller

Low-cost Wi-Fi enabled microcontroller
Ideal for small-scale and DIY IoT projects
Supports integration with various sensors

Blynk IoT Platform

A powerful app-based interface for managing IoT devices
Easily connects to ESP8266 for real-time data visualization
Learn more at Explore Blynk’s IoT Platform

Sensors and Actuators

Soil moisture sensor: Detects the water content in soil
DHT11/DHT22 sensor: Measures temperature and humidity
Relay module: Automates devices like water pumps
Water pump: Controls irrigation based on sensor input

Setting Up the Hardware

Required Components

ESP8266 NodeMCU
Soil moisture sensor
DHT11/DHT22 sensor
Relay module
Water pump
Jumper wires and breadboard
Power supply or battery pack

Circuit Diagram and Connections

ESP8266 Blynk IoT Smart Plant Monitoring System

Connect the sensors to the analog/digital pins of ESP8266
Use the relay to connect the water pump
Ensure correct voltage and ground connections to avoid damage

Power Supply Considerations

Use a 5V battery pack or USB adapter
Consider solar-powered options for outdoor setups

Configuring the Blynk Application

Creating a Blynk Account and Project

Register on the Blynk app and create a new project
Choose ESP8266 as the device and Wi-Fi as the connection type

Setting Up Virtual Pins and Widgets

Assign sensors to virtual pins in the Blynk app
Add widgets like gauges, displays, and buttons
Refer to the ESP8266 Documentation for connection details

Integrating with ESP8266

Generate an authentication token from Blynk
Use the Arduino IDE to upload code to ESP8266
Establish connection using Blynk and Wi-Fi credentials

Developing the Firmware

Programming the ESP8266

Install the ESP8266 board package in Arduino IDE
Include required libraries: ESP8266WiFi, BlynkSimpleEsp8266, DHT, etc.

//Include the library files
#include <LiquidCrystal_I2C.h>
#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <DHT.h>

//Initialize the LCD display
LiquidCrystal_I2C lcd(0x3F, 16, 2);


char auth[] = "     ";  //Enter your Blynk Auth token
char ssid[] = "     ";  //Enter your WIFI SSID
char pass[] = "     ";  //Enter your WIFI Password

DHT dht(D4, DHT11);//(DHT sensor pin,sensor type)  D4 DHT11 Temperature Sensor
BlynkTimer timer;

//Define component pins
#define soil A0     //A0 Soil Moisture Sensor
#define PIR D5      //D5 PIR Motion Sensor
int PIR_ToggleValue;

void checkPhysicalButton();
int relay1State = LOW;
int pushButton1State = HIGH;
#define RELAY_PIN_1       D3   //D3 Relay
#define PUSH_BUTTON_1     D7   //D7 Button
#define VPIN_BUTTON_1    V12 

//Create three variables for pressure
double T, P;
char status;



void setup() {
  Serial.begin(9600);
  lcd.begin();
  lcd.backlight();
  pinMode(PIR, INPUT);

 pinMode(RELAY_PIN_1, OUTPUT);
 digitalWrite(RELAY_PIN_1, LOW);
  pinMode(PUSH_BUTTON_1, INPUT_PULLUP);
  digitalWrite(RELAY_PIN_1, relay1State);


  Blynk.begin(auth, ssid, pass, "blynk.cloud", 80);
  dht.begin();

  lcd.setCursor(0, 0);
  lcd.print("  Initializing  ");
  for (int a = 5; a <= 10; a++) {
    lcd.setCursor(a, 1);
    lcd.print(".");
    delay(500);
  }
  lcd.clear();
  lcd.setCursor(11, 1);
  lcd.print("W:OFF");
  //Call the function
  timer.setInterval(100L, soilMoistureSensor);
  timer.setInterval(100L, DHT11sensor);
  timer.setInterval(500L, checkPhysicalButton);
}


//Get the DHT11 sensor values
void DHT11sensor() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  Blynk.virtualWrite(V0, t);
  Blynk.virtualWrite(V1, h);

  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(t);

  lcd.setCursor(8, 0);
  lcd.print("H:");
  lcd.print(h);

}


//Get the soil moisture values
void soilMoistureSensor() {
  int value = analogRead(soil);
  value = map(value, 0, 1024, 0, 100);
  value = (value - 100) * -1;

  Blynk.virtualWrite(V3, value);
  lcd.setCursor(0, 1);
  lcd.print("S:");
  lcd.print(value);
  lcd.print(" ");

}

//Get the PIR sensor values
void PIRsensor() {
  bool value = digitalRead(PIR);
  if (value) {
    Blynk.logEvent("pirmotion","WARNNG! Motion Detected!"); //Enter your Event Name
    WidgetLED LED(V5);
    LED.on();
  } else {
    WidgetLED LED(V5);
    LED.off();
  }  
  }

BLYNK_WRITE(V6)
{
 PIR_ToggleValue = param.asInt();  
}


BLYNK_CONNECTED() {
  // Request the latest state from the server
  Blynk.syncVirtual(VPIN_BUTTON_1);
}

BLYNK_WRITE(VPIN_BUTTON_1) {
  relay1State = param.asInt();
  digitalWrite(RELAY_PIN_1, relay1State);
}

void checkPhysicalButton()
{
  if (digitalRead(PUSH_BUTTON_1) == LOW) {
    // pushButton1State is used to avoid sequential toggles
    if (pushButton1State != LOW) {

      // Toggle Relay state
      relay1State = !relay1State;
      digitalWrite(RELAY_PIN_1, relay1State);

      // Update Button Widget
      Blynk.virtualWrite(VPIN_BUTTON_1, relay1State);
    }
    pushButton1State = LOW;
  } else {
    pushButton1State = HIGH;
  }
}


void loop() {
    if (PIR_ToggleValue == 1)
    {
    lcd.setCursor(5, 1);
    lcd.print("M:ON ");
      PIRsensor();
      }
     else
     {
    lcd.setCursor(5, 1);
    lcd.print("M:OFF");
    WidgetLED LED(V5);
    LED.off();
     }

if (relay1State == HIGH)
{
  lcd.setCursor(11, 1);
  lcd.print("W:ON ");
  }
  else if (relay1State == LOW)
  {
    lcd.setCursor(11, 1);
    lcd.print("W:OFF");
    }
     
      
  Blynk.run();//Run the Blynk library
  timer.run();//Run the Blynk timer

  }

Sensor Data Acquisition

Read data from soil and environmental sensors
Format and send the data to Blynk using virtual pins

Automating Plant Care

Define moisture thresholds in code
Automatically activate the relay to water the plant

Enhancing the System

Adding More Sensors

Integrate light sensors, pH sensors for comprehensive monitoring
Expand the number of plants monitored with more sensors and pins

Implementing Notifications

Use Blynk to send alerts on low moisture or high temperature

Data Logging and Analysis

Store historical data using cloud platforms
Analyze trends to optimize watering schedules

Troubleshooting Common Issues

Connectivity Problems

Ensure strong Wi-Fi signal
Verify correct credentials in code

Sensor Calibration

Test sensors independently for accurate readings
Calibrate using known reference values

Power Management

Use voltage regulators for stable power
Monitor battery levels with voltage sensors

FAQs

How do I calibrate the soil moisture sensor? Dry and wet calibrations with known water levels help set accurate thresholds.

Can I use other microcontrollers instead of ESP8266? Yes, boards like ESP32 or Arduino with Wi-Fi shields can be used.

How secure is the Blynk platform? Blynk uses secure cloud communications; however, always update credentials and firmware.

What is the range of Wi-Fi connectivity for ESP8266? Typically 30-50 meters indoors, depending on obstacles and router strength.

Can I control multiple plants with one system? Yes, you can use multiple sensors and expand the code accordingly.

Conclusion

The ESP8266 Blynk IoT Smart Plant Monitoring System offers a cost-effective and scalable way to automate and monitor plant care. With simple hardware and powerful app integration, it empowers users to ensure optimal plant health while saving time and effort. Expand and enhance your system to fit your gardening needs.