The Study And Design Of In-car Infotainment System

Automotive electronics has grown from the original single radio player towardcollection of information, entertainment and multifunctional development. A lot ofresearches have been done on Infotainment systems at home and abroad. In otherdeveloped countries, car infotainment system is relatively mature, but there are stillsome problems on application. Automotive products develop rapidly in China, butthere are some problems in the richness of functionality, scalability, informationprocessing speed, power consumption, etc., and cannot meet on the use offunctionality, comfort requirements. Despite the country’s navigation equipment hasbeen very popular, but most of the products are expensive. From abroad existence ofthese questions, infotainment products focuses on solving the multi-functionalintegrated products, signal integrity problems in high-speed signal transmissionprocess, and Linux device drivers’ transplant on different hardware platforms.The design features a number of radio sets, video playback, recording, USBinterface, Bluetooth, wifi, SD card, GPS, etc. in one system. According to therequired function with a variety of processing functions ARM processor R8A7778was selected, according to the processor chip to build peripheral circuits. In thehigh-speed signal processing, mainly deal with the issue in signals of DDR3linktransmission. First analysis the causes of signal integrity, and then design relatedcircuit based on these reasons, the last simulate signal integrity and analysis thesimulated result to find the best solution. Porting the device drivers on the hardwareplatform, determining the interface type of each device, the interface associatedtransport protocol. In contrast to other platforms device driver platform device tocomplete the platform device drivers transplant through rewriting the associatedinterrupt number, the initial value of registers address. Transplant device driversunder Linux according to the way the device itself starts. After the completion ofporting device driver，write related equipment testing procedures to ensure that thedevice can boot normally. After testing, power supply is normal. Linux kernel can boot from the SD cardand SPI flash, DDR3can work properly when run rate at1333Mbit/s. DDR3clockdesigned for testing positive differential signal phase difference of180degrees and beable to meet the level of the standard1.5V DDR3’s. GPS can accept a signal every0.5s, the data will change when G-sensor move around and the sensitivity is about4mg/digit. Sound recording work properly, the video can be played smoothly.Bluetooth can transfer data within8meters. WIFI display can be performed byconnecting WIFI.