Control Raspberry Pi GPIO Pins Using MQTT

The Raspberry Pi has 40 General purpose Input/output Pins (GPIO) that can be used for controlling external hardware. There are  a number of add-on boards called hats which plug into these pins and provide various sensors. The most common one being the sense hat.

Continue reading

Logging MQTT Sensor Data to SQL DataBase With Python

In this project we will create a simple data logger that logs data to a sqlite database.   The project Consists of two modules. A sql logger class module sql_logger.py The logging script. The script uses a main thread to get the data (on_message callback) and a worker thread to log the data. A queue is used to move the messages between threads.

Continue reading

Checking Active MQTT Client Connections

This tutorial is in response to a question I received on the client connections tutorial page: I’ve been struggling to find a real client connection status tool, dashboard or anything which will show a list of my clients and their connection status. Clearly the broker via the low-level protocol mechanics maintain an MQTT keepalive table for each client — that’s how Last Will and Testament (LWT) is triggered internally by the broker. However how does one display such table? The problem is that you have no way of accessing the connections table on the broker so the only way is to

Continue reading

Logging MQTT Sensor Data Using Python

In this project we will create a simple data logger that logs IOT sensor/device data in JSON format to a text log file. The project Consists of two main modules. A logger class module mlogger.py The logging script mqtt-data-logger.py It also has helper module commands.py  which gets and parses command line arguments. Note: There is also the Simple Python MQTT Topic Logger which logs data based on topic that may be more suitable for your project. Logger Class The class is implemented in a module called m_logger.py (message logger). It can be used for logging data from any source not

Continue reading