# Home Automation System Based on Intelligent Transducer Enablers
## 9 Conclusions  
This paper presented the design and implementation of HASITE's architecture, which is focused on a plug-and-play mechanism for home automation systems. The main elements of HASITE are a home automation gateway, Intelligent Transducer Nodes (ITN) and Wi-Fi Access Points (AP). In order to control these elements, three subsystems were defined: the control and management subsystem, the communications subsystem and the transducers subsystem. Intelligent Transducer Enabler (ITE) data structures are a key element in the HASITE infrastructure and are aimed at storing configuration data, easing the access, and at communicating and interpreting the data managed by each ITN and its transducers.  
The self-configuring protocol proposed allows the ITNs to be configured automatically. It relies on a configuration AP and a series of steps between the home automation gateway and the ITNs to request and share the configuration information. This mechanism has three different modes of operation: automatic, dynamic request and previous identifier registration. Each of these modes of operation is aimed at easing the addition of ITNs and providing different levels of security.  
The novel self-detection protocol is able to detect an ITN once configured, storing the record of each node registered and making it available for further access and interaction. The system has an API to access the basic configuration parameters, the registered ITNs, the information of the ITEs and the inputs and outputs of the transducers. Furthermore, a hybrid application for Android and iOS was developed using the API. The application made use of BLE beacons to estimate the user location within a house. Using the approximate location of the user, the application can adjust and customize the interface to display only the controls and information needed for controlling nearby appliances. This smartphone application reflects the power of the ITEs and the API access: all registered ITNs and the ITEs can be obtained with simple GET requests. Once obtained, the information contained on an ITE allows for the easy understanding of the different sensors and actuators controlled by an ITN. The messages, units, maximum and minimum values, among other useful information, can be easily understood by a human, thanks to the use of JSON. In addition, an ITE can be parsed to assign software or hardware controls and displays to a transducer automatically. This simplifies not only the communication with HASITE and its ITNs, but also the creation of reusable GUI elements for similar transducers.  
The use of ITEs as a leading element grants full support of the IoT paradigm, allowing for the use of any RDF notation, such as JSON-LD, and the creation of an ontology around the transducers, which would add automatic control and improve decision making.  
Figure 17: Integration of all ITN interaction response time tests.  
HASITE's architecture was tested using a low-cost and low-consumption SBC solution as the home automation gateway. Several common transducers (a relay, a light dimmer and humidity, temperature, presence and current sensors) were embedded into ITNs. The time performance of the implemented protocols was determined in four different locations of a building. The system was evaluated while using two different APs and different load conditions on the Wi-Fi network. The results were encouraging: the total time was always less than 13 s, the self-configuration and self-registration protocols being completed in less than 2 s.