MQTT

MQTT = Message Queuing Telemetry Transport

Installation

Simple publisher / subscriber app

We need a broker ( here we consider on the RPI ) :

command lines

python programs

MQTT sensor app

terminal display

adding GPIO Led Control

web browser display : MQTT + socket io

SOURCE CODE

web browser can’t support MQTT ; we can make a bridge between our MQTT socket and a websocket.
Here is an example with nodejs:

Raspberry PI Side

In a first terminal :

In a 2nd terminal :

PC Side

Open a web browser and write “192.168.0.2:8080”

Adding Security

Authentification

TLS Encryption

cf server_ssl_tls.html

MQTT on Pycom board (micropython)

Installations

On atom, install Pymakr package.

Application

SOURCE CODE

We suppose mosquitto broker is at address “192.168.200.179”.

Once the program is running on pycom, in a terminal :