uMQTT

uMQTT is a lightweight pure Python MQTT library. It was intended for lightweight embedded systems running older versions of Python (V2.4+).

This implementation is based on the MQTT V3.1 Protocol Specification.

An important difference between uMQTT and other established MQTT libraries (such as Paho) is that uMQTT is designed to be agnostic to the transport method (i.e.: TCP/IP, zigbee, serial, etc). It therefore only provides a suite of tools to generate and parse command messages between the client and the borker. The goal for future versions is to maintain this abstraction while adding threads to facilitate the communication in the background.

The current implementation supports the following command messages:

• CONNECT
• CONNACK
• PUBLISH
• PUBACK
• PUBREC
• PUBREL
• PUBCOMP
• SUBSCRIBE
• SUBACK
• UNSUBSCRIBE
• UNSUBACK
• PINGREQ
• PINGRESP
• DISCONNECT

Getting Started (Mac)

First, you're going to need Python 2.4. This can be downloaded here.

I'm using multiple versions of Python on my Mac, so I had to create an alias to python 2.4 before I could run the main.py example code. This can be done as follows:

alias python24='/Library/Frameworks/Python.framework/Versions/2.4/bin/python'

Next, run main.py in python 2.4:

python24 main.py

Under Development

• Remaining command messages
• MQTT client object
• Callback functions

The MQTT client usage shoud resemble that of Paho. A method of integrating various transport methods will need to be designed.

Paho-like client example:

import uMQTT as mqtt

# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, 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("$SYS/#")

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

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message

client.connect("iot.eclipse.org", 1883, 60)

# 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()