Index
Interface DHT11/ DHT22 with ESP32 & Display Values Using Web Server
Introduction
If you’ve ever wanted to monitor the temperature and humidity in your home, walk-in cooler, or wine cellar from your mobile, tablet, or PC, then this IoT project is a perfect starting point!
In this project, we’ll use the ESP32 as the control device, which connects to your existing WiFi network and sets up a Web Server. Whenever a device connects to this web server, the ESP32 reads the temperature and relative humidity from the DHT11/DHT22 sensor and displays it on the device’s web browser with a user-friendly interface. Ready to begin?
Before we dive in, it’s helpful to understand a few concepts. If any of these tutorials are new to you, it’s a good idea to familiarize yourself with them first:
To delve deeper into utilizing the DHT22 and DHT11 temperature and humidity sensors with the ESP32, refer to our comprehensive guide at: https://www.oceanlabz.in/interface-dht11-dht22-sensors-with-arduino/
Note:
While the ESP32 does feature a built-in temperature sensor with a range of -40°C to 125°C, its accuracy may vary due to process variation between individual chips. Additionally, the sensor’s measurements can be influenced by the heat generated by the Wi-Fi circuitry. As a result, it’s best suited for applications that detect temperature changes rather than precise absolute temperatures.
Wiring a DHT11/DHT22 sensor to an ESP32
Wiring a DHT11/DHT22 sensor to an ESP32 is straightforward. Follow these steps:
- Place the ESP32 on the breadboard, ensuring that each side of the board is on a different side of the breadboard.
- Position the DHT11/DHT22 sensor on the breadboard next to the ESP32.
- Connect the sensor’s VCC pin to the ESP32’s 3.3V pin and the sensor’s ground pin to the ESP32’s ground pin.
- Connect the sensor’s data pin to the ESP32’s GPIO pin D5.
- Lastly, add a 10KΩ pull-up resistor between the VCC and data line of the sensor. This resistor ensures that the data line remains HIGH for proper communication between the sensor and the ESP32.
Installing DHT Sensor Library
To start reading sensor data from the DHT sensor, you’ll need to install the DHT sensor library. Here’s how to do it:
- Open the Arduino IDE and navigate to Sketch > Include Library > Manage Libraries…
- Wait for the Library Manager to download the libraries index and update the list of installed libraries.
- In the Library Manager search bar, type “DHT sensor” and press Enter.
- Look for the “DHT sensor library by Adafruit” in the search results.
- Click on the library entry, and an “Install” button should appear. Click on “Install” to begin the installation process.
- Once the installation is complete, you can close the Library Manager.
Now, you have successfully installed the DHT sensor library and are ready to use it in your projects.
Applications of DHT11/DHT22 Web Server:
- Home Automation: DHT11/DHT22 web servers are integral to home automation systems, enabling remote monitoring and control of temperature and humidity levels for HVAC adjustments and alerts.
- Greenhouses and Agriculture: Widely used in greenhouse and agricultural setups, these web servers help maintain optimal growth conditions for plants by monitoring environmental parameters and triggering alerts for deviations.
- Industrial Monitoring: In industrial settings, DHT11/DHT22 web servers provide real-time data on temperature and humidity, aiding in warehouse, factory, and server room management for equipment integrity and product quality.
Advantages of DHT11/DHT22 Web Server:
- Remote Monitoring: Enables remote access to temperature and humidity data from any location with internet access, facilitating informed decision-making without physical presence.
- Real-Time Updates: Offers real-time updates on environmental conditions, allowing prompt responses to fluctuations and ensuring proactive management.
- Customizable Interface: Provides a customizable interface accessible from various devices, allowing users to tailor data display for enhanced usability and user experience.
