ESP32 DHT11 Sensor with MQTT Integration

This project provides an ESP32 microcontroller setup for reading temperature and humidity data from a DHT11 sensor and publishing it to an MQTT broker. The data can be monitored over an MQTT-enabled network, making it ideal for IoT applications like smart home automation or remote environmental monitoring.

Features

• WiFi Connectivity: Connects to a specified WiFi network.
• DHT11 Temperature and Humidity Readings: Reads environmental data using the DHT11 sensor.
• MQTT Publishing: Publishes temperature and humidity data to a specified MQTT broker.
• Reconnect Logic: Ensures persistent connectivity to the MQTT broker.

Requirements

• Hardware: ESP32 board, DHT11 sensor

• Libraries:

  • Adafruit_Sensor
  • DHT sensor library
  • PubSubClient

  Install these libraries via the Arduino IDE Library Manager or by downloading them from GitHub.

Installation

Installation Instructions

1. Clone the repository

Clone the project to your local machine or directly to your Arduino IDE project folder:

git clone https://github.com/yourusername/esp32-dht11-mqtt.git

2. Install the necessary libraries

Open Arduino IDE and go to Sketch -> Include Library -> Manage Libraries. Search for and install the following libraries:

- Adafruit Sensor
- DHT sensor library
- PubSubClient

3. Upload the Code

1. Open the esp32-dht11-mqtt.ino file in the Arduino IDE.
2. In the Arduino IDE, go to Tools > Board and select your ESP32 board model.
3. Go to Tools > Port and select the correct port for your ESP32.
4. Click the Upload button (the right arrow icon) to upload the code to the ESP32.

Usage

Connect the DHT11 Sensor:

• Connect the Data pin of the DHT11 to GPIO 14 on the ESP32.
• Connect VCC to the 3.3V pin and GND to the ground pin on the ESP32.

Monitor the Data:

• Upon powering the ESP32, it connects to the specified WiFi and MQTT broker.
• Temperature and humidity data are published every 5 seconds to the MQTT topics:
  • W014/temp/thomas - for temperature data
  • W014/hum/thomas - for humidity data

View Data:

• Subscribe to these topics in your MQTT client to view the live data updates.

Code Overview

• initWifi(): Initializes the WiFi connection.
• reconnect(): Ensures connection with the MQTT broker, reconnecting if necessary.
• callback(): Handles incoming messages (currently set to print received messages to the serial console).
• setup(): Sets up WiFi, MQTT, and DHT11 configurations.
• loop(): Continuously reads sensor data and publishes it to the MQTT broker.

Example Output

Example output on the serial monitor:

WLAN verbunden!
IP-Adresse: 192.168.1.2
Verbindung zum MQTT-Broker wird hergestellt...
Verbunden mit MQTT-Broker!
Luftfeuchtigkeit: 45.00 %
Temperatur: 23.50 °C