Python - MQTT Basic Configuration

Using MQTT in python is simple, you can use a library from pypi.org called paho-mqtt please visit this link for more information https://pypi.org/project/paho-mqtt/

The library can be installed by using this command below

pip install paho-mqtt

once the library successfully installed, you can start the coding by follow this steps below:

• Create a new project folder
• Open the visual studio code or any code editor and open the project folder
• Create a python script called app.py
• Copy and paste this script below

import paho.mqtt.client as mqtt

# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
    print("Connected with result code "+str(rc))

    # Subscribing in on_connect() means that if we lose the connection and
    # reconnect then subscriptions will be renewed.
    client.subscribe("/sensor") # topic you want to subscribe

# The callback for when a PUBLISH message is received from the server.
def on_message(client, userdata, msg):
    print(msg.topic+" "+str(msg.payload)) # displaying the data on console

client = mqtt.Client()
client.username_pw_set("/train:trainsensor", password="12345") #vhost username & password
client.on_connect = on_connect
client.on_message = on_message

client.connect("192.168.1.7", 1883, 60) # your mqtt host and port

# Blocking call that processes network traffic, dispatches callbacks and
# handles reconnecting.
# Other loop*() functions are available that give a threaded interface and a
# manual interface.
client.loop_forever()

• Run the script by using command: python app.py
• Testing using MQTT-Box

REMEMBER

make sure that you edit this and pointing to your MQTT host

client.username_pw_set("/train:trainsensor", password="12345")

client.connect("192.168.1.7", 1883, 60)