A Design of Network Digital Audio Public Address System

This paper describes a method of digital audio public address (PA) system based on Ethernet. The main framework of the system is proposed and the core techniques are analyzed. The hardware design of network audio devices and software design are described in details in this paper. CYCLONE II EP2C5FA484 programmable FPGA chip and audio codec VS1003 are proposed in the network audio terminal design, in which μc/OS is performed as the kernel of Nios II processor. Combination of network switch and IEEE 1588 Clock Synchronization are proposed to achieve real-time audio signal transmission. The designed system has high performance and is cost effective.