Marcel

Marcel is a lightweight, versatile MQTT data publisher.

Focusing on smart home automation (but not only), its optional modules publish :

• 1-wire probes environmental figures
• weather forecast
• UPS figures
• external MQTT events
• and many more

Can raise some notifications, manage alerts, and control some devices.

Lua user scripts can be used to build simple automation and/or, to validate incoming values.

Thanks to its open and powerful module's API, it's easy to add new functionalities.

Build from source.md contains technical information if you want to compile directly from its source code.

Dependencies

As the communication is based on MQTT messages, you obviously need a ... broker : I personally use Mosquitto.

Global dependency

Install PAHO library for C ( https://eclipse.org/paho/clients/c/ )

Modules related runtime dependencies

Lua (mod_Lua)

If you want to have user's functions : https://www.lua.org/

1-wire (mod_1wire)

Recent Linux kernel has better than nothing and limited 1-wire support. I strongly suggest using OWFS instead.

OpenWeatherMap (mod_OpenWeatherMap)

You need to provide your own license key to query the weather forecast, it's free for hobbyist usage.
Take a look on : https://openweathermap.org/

In addition, json-c and libcurl are needed.

Launch options :

Marcel knows the following options :

• -h : online help
• -v : verbose output
• -S : runs in "Simulation" mode
• -f : loads as a configuration file. The default one is /usr/local/etc/Marcel.conf
• -t : test configuration file and exit

Simulation mode

When running in "Simulation mode", all sections with the "DoNotSimulate" flag set are considered disabled.

Logging

As of version 6.05, Marcel publishes its logs on the following topics :

• %MarcelID%/Log/Fatal : Failures causing Marcel to stop or major functionality loss
• %MarcelID%/Log/Error : Something went wrong, but it didn't impact Marcel's health
• %MarcelID%/Log/Warning : something you must be aware of
• %MarcelID%/Log/Information : Startup steps and running information
• %MarcelID%/Log : Trace information (incoming messages, decisions, etc …)

As of version 7.07, the following topics have been added (if mod_alert enabled) :

• %MarcelID%/Log/Error : send raising alerts as well (same as Marcel's own errors)
• %MarcelID%/Log/Corrected : send corrected alerts
• %MarcelID%/AlertsCounter : amount of active alerts

Status change

Section

As of 8.3, Marcel reports section status changes to topic
%MarcelID%/Change/

and the payload contains 2 fields:

• Enabled(1) or Disabled (0)
• face technical error

As example, if Marcel/Change/Info is published with

1,0

means, Info section is enabled and doesn't face any errors.

Named Notification (only if mod_alert is loaded)

As of 8.3, Marcel reports Named Notification status changes to topic
%MarcelID%/NamedNotificationChange/

and the payload contains 1 field:

• Enabled(1) or Disabled (0)

As example, if Marcel/NamedNotificationChange/p is published with

1

means, p named notification is enabled.

Modules

Modules contains the documentation for each module.
Taking a look in Modules/Marcel is a must-read about global directives.

Side note

The name is a tribute to my late rabbit, who passed away some days before I started this project : he stayed at home as a keeper. RIP.