A generic device can be interfaced with a general purpose system through an ad hoc driver. Conceptually this approach could be applied also to a sensor network, but there are two relevant differences that must be considered.

First of all the sensor nodes are part of a networked environment, therefore data and commands are related not to a single device but to a variable number of sensor nodes. As a consequence, the driver must be able to adapt to the network general setup organization and changes, and the data received must be associated to the corresponding kind of source in order to avoid wrong data interpretation.

The second aspect to consider is related to the location of the end-nodes in the real world (e.g. on the user body). In order to use acquired data correctly, each application should be aware of node location. As a consequence, to test and use the sensor network, the implementation of an ad hoc standard driver has been abandoned in order to design and implement an innovative multi-input dynamic network driver.

 

At runtime SeNIE is an empty Java toolbox that allows a user to load available plug-ins to read, process and exchange data with other applications. At compile time SeNIE is a framework that allows developers to easily implements new kinds of plug-in or adapters to handle existing applications. The creation of new plug-ins is easy. Developers conceptually just need to implement a JavaBean with the desired function, starting from a base class which depends on the plug-in type and to connect it to a GUI based on an embedded Front-end offered into our framework. This solution has been adopted to keep difference between functions and GUIs in order to obtain hidden implementation of SeNIE drivers. Once a new sensor has been developed it can be easily handled by a runtime driver generator.

 

We choose Java technology because it is platform independent and it can be used into portable devices like PDAs or SmartPhones. SeNIE plug-ins are divided into four main categories related to their functionality: Input, Output, Calibration and Application.

 

Each SeNIE instance is able to communicate with other instances so it is possible to perform distributed computation of sensor data. This communication does not use a specific protocol, simply it uses input/output plug-in to transfer data like every other gateway sensor, using a selected sensor descriptor XML, therefore computer running SeNIE could act as a sensor gateway to other machines or, handheld devices could be used as sensors with the opportune data generator plug-in.