Free Tutorial

IoT-Based Smart Farming System using ESP32 Web Server

Intermediate Difficulty
1 Est. Time
0 items Components Needed

About This Project

The webpage displays live temperature, humidity, soil moisture percentage, pump status, and allows manual control of the irrigation pump. Additionally, the system supports automatic irrigation by turning the water pump ON or OFF according to predefined soil moisture thresholds.

This project is ideal for home gardens, greenhouses, agricultural research, and smart irrigation systems.

Project Features
Real-time Temperature Monitoring
Real-time Humidity Monitoring
Soil Moisture Monitoring
Automatic Water Pump Control
Manual Pump ON/OFF Control
ESP32 Web Server
Mobile-Friendly Web Dashboard
Live Sensor Updates
Pump Status Display
Local Network Monitoring via IP Address
Low Power Consumption

Working Principle
ESP32 connects to the Wi-Fi network.
ESP32 creates an embedded web server.
The web server is accessible through the ESP32 IP address.
DHT22 continuously measures temperature and humidity.
Soil moisture sensor measures the moisture level in the soil.
If soil moisture falls below the predefined threshold, the ESP32 automatically turns ON the relay to activate the water pump.
Once sufficient moisture is detected, the relay switches OFF the pump.
The webpage displays:
Temperature
Humidity
Soil Moisture
Pump Status (ON/OFF)
Auto/Manual Mode
Users can manually switch the pump ON or OFF using buttons on the webpage.

Connections

DHT22 DATA → GPIO 4
Soil Moisture AO → GPIO 34
Relay IN → GPIO 26
Relay VCC → 5V
Relay GND → GND

Components Required

Circuit Diagram

Circuit diagram for IoT-Based Smart Farming System using ESP32 Web Server

Step-by-Step Instructions

  1. Power the ESP32 and connect it to the Wi-Fi network.
  2. Initialize the DHT22 and soil moisture sensor
  3. Create an HTTP web server on ESP32.
  4. Read sensor values every two seconds.
  5. Display all readings on the webpage.
  6. Compare soil moisture with the threshold.

Source Code

Arduino / ESP32 Sketch 
#include <WiFi.h>
#include <WebServer.h>
#include <DHT.h>

#define DHTPIN 4
#define DHTTYPE DHT22

#define SOIL_PIN 34
#define RELAY_PIN 26

DHT dht(DHTPIN, DHTTYPE);
WebServer server(80);

// WiFi Credentials
const char* ssid = "YOUR_WIFI_NAME";
const char* password = "YOUR_WIFI_PASSWORD";

bool pumpStatus = false;

// Soil Moisture Threshold (%)
int threshold = 40;

void setup() {

  Serial.begin(115200);

  dht.begin();

  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);

  WiFi.begin(ssid, password);

  Serial.print("Connecting");

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println();
  Serial.println("WiFi Connected");
  Serial.print("IP Address : ");
  Serial.println(WiFi.localIP());

  server.on("/", handleRoot);
  server.on("/pumpon", pumpON);
  server.on("/pumpoff", pumpOFF);

  server.begin();
}

void loop() {

  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  int raw = analogRead(SOIL_PIN);

  // Convert to Percentage
  int moisture = map(raw, 4095, 1500, 0, 100);

  moisture = constrain(moisture, 0, 100);

  // Automatic Pump Control

  if (moisture < threshold) {
    digitalWrite(RELAY_PIN, HIGH);
    pumpStatus = true;
  }
  else {
    digitalWrite(RELAY_PIN, LOW);
    pumpStatus = false;
  }

  server.handleClient();
}

void pumpON() {
  digitalWrite(RELAY_PIN, HIGH);
  pumpStatus = true;
  server.sendHeader("Location","/");
  server.send(303);
}

void pumpOFF() {
  digitalWrite(RELAY_PIN, LOW);
  pumpStatus = false;
  server.sendHeader("Location","/");
  server.send(303);
}

void handleRoot() {

  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  int raw = analogRead(SOIL_PIN);

  int moisture = map(raw,4095,1500,0,100);
  moisture = constrain(moisture,0,100);

  String page="<!DOCTYPE html><html>";
  page+="<head>";
  page+="<meta http-equiv='refresh' content='3'>";
  page+="<title>Smart Farming</title>";
  page+="</head>";

  page+="<body style='font-family:Arial;text-align:center;background:#e8f5e9;'>";

  page+="<h1>🌱 IoT Smart Farming</h1>";

  page+="<h2>ESP32 Web Server</h2><hr>";

  page+="<h3>Temperature : ";
  page+=String(temp);
  page+=" °C</h3>";

  page+="<h3>Humidity : ";
  page+=String(hum);
  page+=" %</h3>";

  page+="<h3>Soil Moisture : ";
  page+=String(moisture);
  page+=" %</h3>";

  page+="<h3>Pump Status : ";

  if(pumpStatus)
      page+="<font color='green'>ON</font>";
  else
      page+="<font color='red'>OFF</font>";

  page+="</h3><br>";

  page+="<a href='/pumpon'><button style='width:120px;height:45px;font-size:18px;'>Pump ON</button></a>";

  page+="&nbsp;&nbsp;";

  page+="<a href='/pumpoff'><button style='width:120px;height:45px;font-size:18px;'>Pump OFF</button></a>";

  page+="<br><br>";

  page+="<h4>Auto Pump Threshold : ";
  page+=String(threshold);
  page+=" %</h4>";

  page+="<p>Refreshes every 3 seconds</p>";

  page+="</body></html>";

  server.send(200,"text/html",page);
}
Note: Install Libraries Install these libraries from the Arduino IDE Library Manager: DHT sensor library by Adafruit Adafruit Unified Sensor Replace: const char* ssid = "YOUR_WIFI_NAME"; const char* password = "YOUR_WIFI_PASSWORD"; With your WIFI Credentials Select ESP32 Dev Module. Upload the code. Open the Serial Monitor (115200 baud). Note the IP address, for example: 10.2.12.123 Open a browser on any device connected to the same Wi-Fi network and visit: http://10.2.12.123 This will display a simple web dashboard showing the temperature, humidity, soil moisture, pump status, and Pump ON/OFF buttons.

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