This tutorial demonstrates how to build a simple, yet effective, system for monitoring temperature and humidity using an ESP32 microcontroller, a DHT11 or DHT22 sensor, and a Wi-Fi connection. The project's real-world value lies in its ability to remotely monitor environmental conditions, making it applicable in various scenarios.

Practical Applications:

• Monitoring a home greenhouse

• Tracking temperature and humidity in a storage facility

• Building a weather station

• Creating a remote environmental monitoring system for a farm

Hardware/Components

This project utilizes SunFounder's ESP32 IoT Learning Kit (in video at 00:16), which includes an ESP32 microcontroller with built-in Wi-Fi and Bluetooth, a DHT11 or DHT22 sensor (in video at 00:07), and other necessary components. The kit also provides an 18650 lithium battery and charger (in video at 01:22), allowing for off-grid operation.

Wiring Guide

The tutorial demonstrates connecting the DHT sensor to the ESP32. Specific pin assignments are detailed in the code.

%%WIRING%%

Code Explanation

The provided code (in video at 04:02) uses the DHT sensor library to read temperature and humidity values. The ESP32 acts as a web server, serving a webpage that displays these readings. Key configurable parts of the code include:

• Wi-Fi Credentials: The ssid and password variables (in video at 06:21) must be set to your Wi-Fi network's SSID and password. Ensure that the SSID is case-sensitive.

• Sensor Type: The DHTTYPE (in video at 05:38) constant defines whether you are using a DHT11 or DHT22 sensor. Uncomment the appropriate line to select your sensor.

• Units: The unit variable (in video at 04:57) controls whether the temperature is displayed in Celsius (0) or Fahrenheit (1).

• Refresh Rate: The refresh variable (in video at 04:31) sets how often the webpage updates (in seconds).

• Serial Output: The showSerial variable (in video at 04:38) enables or disables serial monitor output.

The sendTemp() function (in video at 06:55) constructs the HTML page to display the temperature and humidity readings. The handleNotFound() function (in video at 08:42) handles requests for non-existent pages.

const char *ssid = "YOUR_SSID";
const char *password = "YOUR_PASSWORD";
const int refresh = 10; // Update every 10 seconds
boolean showSerial = false; // Disable serial output
unsigned int unit = 0; // 0 for Celsius, 1 for Fahrenheit

Live Project/Demonstration

The video (in video at 15:11) demonstrates the project's functionality. The ESP32's IP address is obtained, and the webpage is accessed via a web browser or mobile device to view the temperature and humidity readings. The video also shows how changing the unit variable in the code alters the displayed units.

Chapters

• [00:00] Introduction and Project Overview

• [00:25] SunFounder ESP32 Starter Kit

• [01:40] Internet of Things (IoT) Concept

• [02:21] ESP32 as a Web Server

• [03:35] Software and Library Installation

• [04:02] Code Overview and Explanation

• [13:29] Selecting the ESP32 Board and Port

• [15:11] Project Demonstration