Research Of Vehicle Navigation System Design Based On Embedded Technology

Previous vehicle navigation systems have some shortcomings, such as bulky hardware, software redundancy, high power, high cost, and so on. In addition, since the using environment is unique, vehicle navigation system must be small in size, low power consumption, processing power and a simple and convenient operation.According to the characteristics and function requirements of the vehicle navigation system, using the embedded technology, this paper researches a small size, low power consumption and powerful vehicle navigation system.According to the system function demands, the 16/32 RISC embedded microprocessor S3C2440A which is produced by SAMSUNG corporation is a core of the hardware platform. The memory module is used to storage the starting code, the embedded Linux operation system, the electronic map and so on. The keyboard module is used to the basic operation of the navigation system. The touch screen provides a better man-machine interface. The audio module is for the voice navigation. The power management module for the management of the system's power supply. MC35i GPRS modules which produced by Siemens is using for wireless communications. JP7 GPS module which is produced by Falcom is using for the global positioning. Moreover, the hardware platform also includes the function parts such as USB, SD card and others.In the development of the software, installing a set of Linux operation system (RedHat 9.0) as a software development environment on the host PC, for transplanting and compiling operation system, and compiling driver program.In order to provide sufficient memory resources for the compiler, it builds a cross-compile environment, which integrating the compiler, linker and so on. Using GNU tools to compile and link the program in Linux environment. Compiling the program which will running on the target machine on high perference host PC. The operation can generate the code format that can be runned on target machine, and then download to the target machine to run. For driver development, it uses Linux device driver to realize the functions such as initializing and releasing the device, transminting the data from the kernel to the hardware and reading the data from hardware, reading the data which transmiting from the application program to device file and sending back the data that the application program requests, detecting and dealling with the error of device, and so on. Meanwhile, it establishes the data structure of Linux device driver, and realizing the registration and unregistration of Linux device driver, and realizing the design of LCD driver.It achives the basic function after debugging and testing the system.