The Design Of Audio Transmission System Based On LPC2138

This paper designs and realizes a professional audio transmission equipment of Audio IP based on LPC2138. Audio IP is the key technology of the new generation audio transmission equipment, and combines the ARM control and audio transmission. In this paper, the analysis of the audio transmission equipment,the study and implement of several important technology in the design process laid a solid foundation for the final full realization of the audio transmission equipment.Audio IP is connected more by network in the studio and launch transmission equipment, it can achieve a live connection. Audio IP can spread audio data streams stably, simply, effectively through IP data network.The IP data network can be LAN, WAN, Internet, Wireless3G and wifi. Two Audio IP’s connection is established less than10seconds, the network latency is less than2seconds (which can be configured to achieve the best results). Throuth anti-shake mechanism, real-time transmission technology, and ensure the continuous transmission, trasfer effects can reach the sound quality of the professional broadcast FM.According to the functional requirements of the Audio IP audio transmission, this paper developed a system design program, and analysed its implementation process in the hardware system and software system. In the hardware design system, the paper described the design of ARM7chip LPC2138’s peripheral circuit, including serial ports, JTAG and reset circuit; analysed the DIP switch, analog volume knob, button and LCD OLED circuit in user interface design; analysed the digital audio sampling chip, the clock of the audio circuitry, analog audio input/output adjustment, analog audio signal conversion, input/output adjustment of the digital audio signal, D/A conversion of audio signals and the audio A/D channel switching in the audio circuit design, and described the circuit of USB,3G, wifi, too. The design of software system includes the preparation of the ARM program, AAC audio encoding and decoding, PPP protocol in the audio transmission, the3G dial-up and TCP/UDP transmission. Finally, the paper analysed the hardware debug, device transmission performance indicators are analyzed, and analysed the problems in the system design.The chapter arrangements of thesis divided into the following:Chapter one,Introduction. A brief introduction on this topic.the current development status of the Audio IP, as well as the purpose and meaning of the thesis research.Chapter two, The overall system design.The main block diagram of the thesis design in this chapter made a brief introduction.Chapter three, The hardware system design.This chapter discusses each module design principles of the hardware.Chapter four, The design of LPC2138’s program.In this chapter is mainly about the design that the LPC2138’s control program for the front panel, the serial port to send and receive program with the PC.Chapter five,The audio transmission.In this chapter introduces that AAC encoding and decoding processes of the high quality sound,3G dial-up,two ways of audio transmission is TCP and UDPChapter six,The debugging and performance analysis. In this chapter introduces hardware and software debugging and performance analysis of the Audio IP.Audio transmission equipment has been widespread concern across the country radio station for its high cost, low power, scalable, rapid development. In today’s era of rapid development of broadcast media equipment, the AIP will be an irreplaceable position in the future on the market with its unique performance, network and intelligent features.