Bluetooth Portable Music Player System With Realization

With the rapid development of embedded technology, various kinds of electronic entertainment products of the car become popular, they are developing to be multipurpose and simply designed, but these kind of high-tech products are implemented in high-grade cars, while the majority of the public transports have little of the equipments. Taking the music playing system for example, in the most of the modern public transport, the system broadcast the music which is playing, the passengers can not choose the music which they like but only listen to the music which is playing right now passively. In such cases, there will be two contradictions:1. In many cases, some passengers do not want to listen to the music, but it is broadcasted, they can only tolerate the interference caused by sound. If the sound is outputed to the listeners through Bluetooth headset, there would be no mutual interference.2. Some of the passengers may want to choose the music which they like just as what they can do in the KTV system, but the traditional music playing system in the transport can not support such function. Now many ordinary mobile phones can support Bluetooth well, if we can take full advantage of Bluetooth technology in embedded systems to achieve the function of music selection, then the two contradictions above can be solved.This thesis was to address the above contradictions; it proposes one kind of mobile music playing system solution based on Bluetooth technology.This thesis mainly analyzes and designs a low-cost and high performance mobile music playing system based on Bluetooth, ARM and the ARM Linux platform. As to the hardware part, the thesis builds the UDA-based audio decoding circuit based on IIS bus, on the foundation of design and implementation of the hardware of decoding module; it analyzes the implementation of the UDA1341 audio device driver. As to the software, the paper analyzes the hierarchical structure and data flow of the classic BlueZ Bluetooth protocol stack, and how to port it to ARM Linux platform, then focuses on the system's main modules including: music player control module, music files uploading module, music file download module, and on-demand service control module. In the process of implementing the modules, the paper adopts the multi-threaded parallel processing programming ideas to improve system efficiency. The flow chart of modules and main data structure are included in the paper also.Though it is difficult to find such kind of equipment in the current public, hopefully it can propel the evolution of traditional music playing method in the public transports. It is believed that in the future the in-vehicle systems which have the functions introduced above will have a broad market prospect.