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SensiNact/Bridge MQTT
Contents
Description
This bridge allows sensinact to subscribe to a topic, and materialize a sensinact device based on this topic messages. The devices will be display just after its configuration (once the .cfg file is deployed, check below) but the value will be update upon the message arrivals.
Sensinact version
This bridge is available in version 1.5-SNAPSHOT
Requirements
- mqtt-sb bridge activated (via
sensinact -c
) - A mosquitto server running
Capability
- Create a sensinact provider from a message receveid from a MQTT broker topic.
- Instantiate multiple providers, as many as there are configuration files respecting the pattern “mosquitto-*.cfg“, the content format example can be seen below
- Pre-process the message content from the MQTT topic, check the section about
processors
How to instantiate
Declarative file
The declarative file allow you to create at runtime a device mapped to a mosquitto topic. According to the topic
information added in the file (that will be explained below) you will have a device connected directly to your MQTT broker topic.
In order to create the instance of your device inside sensinact platform you have to create a file that respect the certain pattern mqtt-*.cfg
where *
can be any string that identify your rule, this will be assigned as your OSGi service PID (for more details check felix Configuration Manager). This configuration file MUST be deployed in the directory $SENSINACT_HOME/cfgs.
The fields in this file are define as in a regular property file, that by definition contains a list of key
and values
pairs separated by =
. The allowed fields are specified in the list in BNF extended format below .
id=ALPHA; mandatory host=ALPHA;default=127.0.0.1 port=ALPHA;default=1883 protocol=["ssl"|"tcp"];default=tcp topic=ALPHA; mandatory topic.type=["mqtt"|"smarttopic"];default=mqtt processor=([PROCESSOR["$"[PROCESSOR_EXPRESSION]][","])* location.latitude=DIGIT location.longitude=DIGIT auth.username=ALPHA auth.password=ALPHA discovery.firstMessage=["false"|"true"];default=false
Some processors do not require a PROCESSOR_EXPRESSION, refer to the processor specific topic to get more details
One example of file (named mqtt-1.cfg
) content is shown below:
id=counter topic=/camera
SmartTopic
Using regular topic
you can only attach one device to one topic and you cannot define the service and resource name in which this information will be attached. For this reason the smarttopic was created, its is an language inside a regular MQTT topic that allows the user to specify which portion of the topic will be considered as provider, which as service and so on.
In smarttopic only the {provider}
tag is mandatory, case service
or resource
are not specified the values info
and value
will be adopted. You can also indicate the value defined for your sensinact devices in the topic using the tag {value}
, case