MQTT Publisher-Subscriber Example using Python and Tkinter

This is a simple example of an MQTT (Message Queuing Telemetry Transport) publisher-subscriber application implemented in Python using the Paho MQTT client library and the Tkinter GUI framework. MQTT is a lightweight messaging protocol often used in IoT (Internet of Things) applications for efficient communication between devices.

Prerequisites

• Python 3.x installed on your system
• Paho MQTT client library (paho-mqtt) installed. You can install it using the following command:

4. The graphical user interface (GUI) window will appear with two buttons: "Start Publisher" and "Start Subscriber".

5. Publisher: Click the "Start Publisher" button to initiate the MQTT publisher. This will generate random temperature values and publish them to the MQTT broker on the topic home/bedroom/temperature at regular intervals.

6. Subscriber: Click the "Start Subscriber" button to initiate the MQTT subscriber. The subscriber will connect to the MQTT broker and listen for messages on the home/bedroom/temperature topic. When a message is received, it will be displayed in the output text area.

7. To stop the publisher or subscriber, you can close the application window.

Important Notes

• Make sure you have a working MQTT broker available. The code uses the mqtt.eclipseprojects.io broker by default, but you can replace it with your own broker's address and port in the mqttBroker and mqttPort variables.

• The MQTT publisher generates random temperature values between 20.0 and 21.0 degrees Celsius. You can modify the randNumber assignment in the publisher() function to generate different values.

• The on_connect() and on_message() functions handle the connection to the MQTT broker and the processing of received messages, respectively.

• The GUI is built using the Tkinter framework, providing buttons for starting the publisher and subscriber, as well as a text area to display output messages.

• Exception handling is implemented in case any errors occur during the MQTT operations.