SensorNode

Description

SensorNode is one component of a project to build a sensor network. It aims at connecting multiple sensors to a sensor node, and multiple sensor nodes to a server from where the data can be accessed via a web application and/or a mobile application. In this case, sensor can be seen as a broad term. It can be any device that delivers data which can be stored.

The application has two main components: the sensor management and the sensor data management. The sensor management initiates and controls the connected sensors. The sensor itself reads data from the hardware device regularly in a specified capture interval and puts it into a data queue. The sensor data management is responsible for storing data to and retrieving it from a database. The data is taken from the data queue to be stored in the database.

Dependencies

Gradle

• http://www.gradle.org/
• Gradle is used for managing the dependencies and as build tool

Set up

1. System config Config file: src/main/resources/config.xml Copy the config.example.xml file and rename it to config.xml.
   Set the path and filename for the database file:

    <config>
        <database>
            <file>data/.sensorNodeDb</file>
        </database>
    </config>
   

2. Sensor config Config file: src/main/resources/sensors.xml Copy the sensors.example.xml file and rename it to sensors.xml.
   Every connected sensor needs to be configured in the sensors.xml file.
   Fields:

   • id: A unique identifier for the sensor
   • name: A name for the sensor
   • device: Currently two types are supported:
     • dummy: A simple "device" for testing, it automatically generates random data
     • file: Reads sensor data from a file.
       • path: The absolute path to the file
       • adapter: Currently only the "temperature" adapter is available. It expects a string in the format "Temperature: 20.1" in the file. The temperature "20.1" is then extracted and saved.
   • captureInterval: (Optional) Describes the interval in milliseconds for capturing/reading the sensor data. Default is 3 seconds.
   • dataType: (Optional) Describes the type of the captured data, so that it can be transformed back by the systems consuming the data from a sensor node. As a convention it expects a MIME-Type because it is widely known format for describing a content's type. Default is "text/plain".

   Examples:

        <sensors>
            
            // creates a dummy sensor for testing
            <basic>
                <id>101</id>
                <name>DummySensor1</name>
                <device type="dummy"/>
                <captureInterval>20000</captureInterval>
                <dataType>text/plain</dataType>
            </basic>
        
            // creates a sensor where the information is stored in a text file
            <basic>
                <id>103</id>
                <name>Remote temperature sensor</name>
                <device type="file">
                    <path>/path/to/temperature.txt</path>
                    <adapter type="temperature"/>
                </device>
                <captureInterval>30000</captureInterval>
                <dataType>text/plain</dataType>
            </basic>
        
        </sensors>
   

Run application

Either use the gradle run task:

./gradlew run

Or build a fat jar and run it with the java command:

./gradlew fatJar
java -jar build/libs/SensorNode-all-1.0.jar