Design And Realization Of I~2C-GPIO On Vehicle Traveling Recording System

With the rapid development in the automobile industry both domestically andinternationally, people have been granted better life standards as well as greater wealth.However, with the increase of automobile usage, more and more people rely heavily upontheir automobiles as well as other transportation devices. Due to such reasons, the need forreal-time automobile diagnostic systems has gradually increased and thus the developmentof such system has become an important task that needs to be done. Therefore, theinstallation of a storage device and system onboard can record something like speed andother automobile information has become essential in modern day automobiles.A Vehicle Traveling Recording system also known as a VTR, is a device used torecord the automobile information like seed of vehicle mileage time or something. Such adevice records vital data that could prevent fatigued drivers from driving, driving overspeed limits, and most important data that could ensure a vehicle's safety.The VTR used in our abstract uses the RISC CPU AT91SAM9260 produced by theATMEL. AT91SAM9260 is a microprocessor designed to be used in heavy industry, it notonly supports JAVA, it also supports DSP extender, a built-in 100M Ethernet CPU, as wellas USB2.0 protocol for Device and USB HOST interface, supports a 9-line UART,SD/MMC slot, high precision PCB, that can withstand industrial level temperatures. It alsohas a steady performance when running on 200MHZ, contains all of the possible pins thatare used currently, and plenty of room for further development. When it operates at180MHZ, it can have up to 200MIPS, furthermore it comes with a MMU memorycontroller unit. The VTR this abstract uses is definitely robust, suited and designedspecifically for industrial uses, and more importantly have powerful networking capabilities.All these requirements make the AT91SAM9260 a good device to serve as our VTR.The AT91SAM9260 microprocessor also supports several different embeddedoperating systems, ranging from WinCE to Symbian, to Linux.WinCE was developed by Microsoft to serve as an embedded systems OS, the systempossesses powerful real-time capabilities, as well as a wide-range of applicable uses. The WinCE is a great platform for developers who are used to programming under the Windowsenvironment. Meanwhile, it also benefits from many other perks as well, being an OS thathas been well established throughout the recent years; many programs are readily availablefor use. Symbian is also an OS designed and created by Nokia, and is one of the mostwidely used embedded systems OS. Most of its uses tend to lean towards mobilecommunication devices, and like WinCE it too is not an open-source OS. Thedisadvantages of these two OS are; Symbian aside from telecommunication capabilitiesonly, its developing process and environment is also tedious. WinCE on the other handrequires users to pay a small fee in order to use their OS, for the embedded systems industry,where cost is everything; this is a really huge disadvantage.Embedded Linux is an open-source, real-time, multi-task embedded OS. It not onlypossesses great stability but also a designable and configurable core, making it an excellentchoice when it comes to selecting a suitable environment to develop embedded systems.Linux being open-sourced and free to use, has gathered many people both domestically andinternationally to develop tools and improve its Linux embedded OS. Through the entireenhancement made in the previous years, it not only surpasses other systems in size, butalso has greater stability.The GUI of the embedded Linux is also well-designed, giving users a range of toolsand applications for users to use. The GUI is certainly user-friendly as well as easy tonavigate and carry. Given all these advantage, in this paper we choose to develop oursystems on the embedded Linux.AT91SAM9260 has three 32 bit PIO (Parallel Input/Output) port that can beestablished as a general I/O port, but due to its ports having both Input and Outputabilities, when the system is undergoing extension processes, the GPIO will have certainresource problems. Therefore, it is important to assign the I2C bus when extensionprocesses are taken.Our abstract uses the I2C bus driver chip to process extension drivers of GPIOcomponents. Through Arm-Linux-GCC compilers we go through Minicom, TFTP mainservers, NFS servers, Linux core, then finally through the I2C bus we startup the PCA9505made by Philips.The Philips PCA9505 is CMOS consisting of 24 pin, it provides a 16 bit general I/Opin that can be used by the I2C bus when we are conducting I/O extension processes. Itsdriver abilities are strong; running on a small voltage of 5V, that provides different I/Ocomponents distributions and micro packets. In this abstract, we used the AT91SAM9260 made by ATMEL as our mainmicroprocessor, through it we then introduced the Embedded Linux to serve as adeveloping environment for our VTR system. Through which, we have to use the PCA5555to conduct I/O extensions and finally use the Linux ver 2.6.25. Under which, weconstructed our services as well as covered a little bit into the GPIO controller portion ofour project and how we came to overcome the problem. Allowing us to completely transferthe embedded Linux system into our device, finished the required adjustments needed withthe PCA555 chip drivers. Allowing us to load and use current applications and softwareavailable under the Linux environment, to develop a real-time VTR system for tests andsimulation runs.