SensiNact/Bridge MQTT

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