Design And Implementation Of Address Book System In Vehicle-Mounted Avigation

Today along with the fast growth of China's economic and the rapidly development of China's automobile industry, the consumption requirement of vehicle-mounted navigation products is increasing greatly, which boosts the development of vehicle-mounted navigation products extremely.The vehicle-mounted navigation entertainment system which combines many functions such as video and audio play, GPS navigation, communication, is the developing trend of vehicle-mounted entertainment electronic products.The thesis mainly is to design and research the communication system in the vehicle-mounted navigation system.With the analyzing of domestic vehicle-mounted navigation system products, some problems was found in the following points: 1. The amount of saved data is very small, the speed of reading data or saving data is slow, 2. These product function is single, many products only support GPS navigation and radio functions, does not support communications function; etc. 3. System's speed is slow, 4. System debug is very difficultly.The thesis mainly aims at these problems: design the addressbook system in the vehicle-mounted navigation system. By using multi-thread,embedded database Sqlite,message mechanism and Log information output, these problems were solved.At thesis, it analyses domestic and international development situation of vehicle-mounted navigation system and introduces the design of main content with starting from the research's background.On the whole,the system software design's characteristic is told in the thesis, and then each module of the system's software is introduced in detail.The system software design based on WINCE6.0 embedded operating system is the keystone in the thesis, which includes multi-threaded applications, embedded database Sqlite, message mechanism and LOG information output design and implementation.Windows CE is a multi-tasks operation system with priorities. It allows multi-functionalities, multi-process running in the system at the same time. It supports 32 bits synchronized process maximally. One process can have more than one thread. Every thread is an independent part of the process. One thread will be specified as the base thread of the process. Multi-threads application part researches the realize, theory and application of the multi-threads mechanism in Wince.Message mechanism researches the status machine, which is the realization of the one to one status chart and the message recycle mechanism. The obvious advantage of the one to one status chart of event is that it is easy to verify the consistency of the global variables. On the other hand, it can provide the necessary text explanation to such kind of variables so that it can be understood globally easily. The one to one status chart of the event expresses the event process functions which are encapsulated in the objects by status.The research of the Sqlite database focuses on the realization during the applying of it. Sqlite database supports ACID transaction. It didn't only guaranty the consistent of the data but also improved the runtime performance. It provides the most functionally support of the SQL91: support multi-table query and index, transaction, view and trigger. It also supports embedded SQL. Because of the embedded system, the requirement for the database volume is very high. Sqlite is the database which was developed for embedded system. It needn't network configuration, Sqlite can be used as long as the basic text operation is available. The configuration of the Sqlite is simple. Basically, it needn't any temporary memory. This thesis will describe the usage of Sqlite database via 5 basic operations.The address book which is downloaded from mobile phone will be transferred by vCard format, it will be conveyed by the fixed length char* via Event. The address book will store the data temporally once it receives the data. When the transportation is finished, the data between BEGIN: VCARD and END:VCARD will be extracted in loop. It will be combined as address book and saved in Sqlite database. The research on vCard focus on 2 points: the layer architecture of the PBAP communication and the realization of the vCard information parsing.The key point of the research of Log output is how to define the priorities of the LOG information and definition of the LOG output format. It is useful to locate and debug the error.The verification of the functionalities and performance can be done by the integration testing of the system. Analyzing the testing result data can be used to verify the robustness and rightness.Finally, it concludes the content of the research of the system and proposes the disadvantages and the directions in the future.