Research Of Vehicle Multi-interface Audio Play System

With the development of digital technology, more and more embedded products begin to have multi-interface features such as USB interface,SD interface,MMC interface and so on. But these features are widely used in the portable device and family entertainment device. As the auto industry quickly develops, the car's features are being improved. Consumers expect to enjoy same experience in the car. At the same time, audio compress music such as MP3,WMA also begins to be paid attention by automatic field. So a new junction that is vehicle audio play system turns out among the car flied,audio compress and internet. Then how to realize universal multi-interface becomes the key of vehicle audio play system.In view of car entertainment and user demand, a kind of multi-interface scheme is putted forward and the design thought and implements method of hardware and software is discussed in the thesis. Hardware and software decoding method is introduced in the thesis. User can select audio files from U disk,SD card and MMC card through USB,SD,MMC interface separately. Then play them through car acoustics after audio decoding,DAC transfer and power enlarging.The design of the vehicle multi-interface audio system makes use of LPC2131,which is produced by PHILIP Corporation, as dominate controller, and uses SD,MMC card and U flash card as storage media. In addition, decoded section uses VS1003 which is produced by VLSI Corporation. With above three dominate section we can realize the play function of audio files. According to the need of system, the system is divided into two sections: hardware and software section, and is designed in multi-mode. The system includes the communication between LPC2131 and VS1003, the communication between LPC2131 and secure digital card and USB interface, the communication between VS1003 and secure digital card and U flash card, the transplant of FAT16 file system in ARM stage and so on.The design introduced in the thesis is feasible in theory, and its product also satisfies with market needs. At the same time, because the system makes use of embedded structure, its function expansion becomes easy in the future. In a word, the system has wide developed foreground.