Category: MQTT-SN

Paho MQTT-SN Gateway can act as a transparent gateway or aggregating gateway depending on settings in the configuration file. The Gateway enables MQTT-SN clients to send messages to other MQTT-SN clients and to MQTT clients.

Anyone familiar with MQTT is familiar with the mosquitto_pub and mosquitto_sub test tools. MQTT-SN also comes with publish and subscribe equivalents mqtt-sn-pub and mqtt-sn-sub.

In this tutorial we will look at how you can subscribe and publish to topics using the Python MQTT-SN client. In addition we also look at topic registration as this is also part of the publish process The client is available to download at the bottom of this page.

MQTT Topics are UTF-8 strings structured in a hierarchy similar to folders and files in a file system using the forward slash ( / )as a delimiter. To be valid a topic must be at least 1 character long and generally in real world applications they 10s of characters in length. The topic is sent with every message published, and so in order to reduce the length of published messages MQTT-SN uses shorter topic names. it does this by using a variety of topic identifiers in place of standard topic name used in MQTT.

The RSMB MQTT-SN broker written by Ian Craggs of IBM isn’t currently being actively developed, but it is still invaluable for anyone wanting to get experience using MQTT-SN. See What’s happening with RSMB? Where are we with MQTT-SN

The MQTT-SN client used here is the client from the RSMB source files but upgraded to python 3, and modified to work in a similar fashion to the Paho MQTT client. I created it so that I could learn more about MQTT-SN and you should note it is still a work in progress. I would not recommend it in a production environment and would be grateful if you would let me know of any problems with it. Downloads are at the end. The client consists of 4 files. You can copy these source files into the site packages folder under