Συντάχθηκε 17-05-2013 14:29
από Eleni Stamataki
Email συντάκτη: estamataki<στο>tuc.gr
Ενημερώθηκε:
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Ιδιότητα: σύνταξη/αποχώρηση υπάλληλος.
Τμήμα Ηλεκτρονικών Μηχανικών & Μηχανικών Υπολογιστών
ΠΑΡΟΥΣΙΑΣΗ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
ΖΑΡΙΦΗΣ ΚΩΝΣΤΑΝΤΙΝΟΣ
με θέμα
“An Application for Controlling a Wireless Sensor Network Using a Smartphone”
Τρίτη 21 Μαΐου, 14.00 μ.μ
Αίθουσα, 141.Α11 (Αίθουσα Συνεδριάσεων Softnet), Κτίριο Επιστημών, Πολυτεχνειούπολη
Εξεταστική Επιτροπή
Επ. Καθ. Αντώνιος Δεληγιαννάκης (Eπιβλέπων)
Καθ. Μίνως Γαροφαλάκης
Επ. Καθ. Άγγελος Μπλέτσας
Περίληψη
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Abstract
The use of smartphone devices over the past years seems to follow a growing trend. This great acceptance along with the endless possibilities that go hand to hand with having a mini computer at all times within reach, can explain this vast interest shown by solo developers and major companies in the mobile industry. As a result, many innovative applications roll out daily to the various online stores, making the lives of the smartphone users a lot better. This thesis describes the design and implementation of a mobile app, a Web Service and a TinyOS application, that bind together allowing the user to execute a variety of queries on a sensor network from any place in the world.
Until now, the user of a sensor network was usually constrained to be in the same room or area in which the network was installed in order to execute a query and receive the measurements retrieved by the sensors. Although nowadays there are various programs that enable users operate a sensor network, they do not effectively resolve some issues that arise. Many of these programs do in fact have a graphical user interface (GUI) that allows the users to operate on it, but it is usually somewhat outdated and abstract. As a result the user can easily get confused while using it. Additionally, since they have not received any major updates recently, they usually cannot run on modern operating systems and more importantly, they can only run on conventional computers and not on mobile devices.
The user of the mobile application developed as a part of this Thesis on the other hand, can operate a Wireless Sensor Network (WSN) without the aforementioned limitations. The user-interface of this app is simple and easy to use, following the trends set by Google and other major companies. Additionally, since this is a mobile application, the user can use it while on the go, without geographical restrictions. He could be in the same room where the sensors are installed, or in an entirely different continent and still be able to use the sensor network, as long as there is internet access.
Mobile applications certainly have many advantages over applications that are intended to run on desktops or laptops but they also come with some restrictions. The limited battery life that the majority of these devices have is without a doubt the most important concern for a developer. Big screens with high resolution may be easier to view and operate on (not to mention impressive), considering the fact that almost every single smartphone produced today comes with a touch screen, but it has a big impact in battery life. The same applies to radio usage, Wi-Fi and 3G-4G networking can drain the battery within a few minutes of heavy traffic. The mobile app developer should also keep in mind that even if the majority of these device have a respectable processing power for a mobile device, it really is no match for the processing power of conventional desktops and laptops. Additionally, the fact that these smartphones support multitasking can effect even more the already limited processing power. What multitasking means is that other processes are executed simultaneously. As a result other processes may use the same resources that our application does. It is therefore important to develop applications that do not overuse the provided resources, as this may cause problems to other applications running on the background.
More or less the same principles apply when developing the applications that run on the sensor network. While the Operating System used by the motes is fairly lightweight and the CPU as the rest of the hardware configuration does not seem to be very power consuming, it is important for the developer to keep in mind that he should find ways to keep radio and CPU usage to the minimum. Furthermore, these devices have a limited flash memory which means that the executable has to be relatively small as well.
Last but not least, in order for the before-mentioned parts to tie together, a web service had to be implemented. The client, which in this case is the mobile application, interacts with the mote network using internet access. In order for this to be possible the client should first interact with a web service that "listens to" a specific public internet address which in turn interacts with the mote network. Basically, the role of the web service is to disseminate messages between the mobile app and the sensor network and to keep track of the activities that take place.
