设计了一种基于ARM7微控制器和以太网的实时语音录放系统。在局域网中,上位机采用广播的方式向各个下位机发送ADPCM语音数据包,下位机对接收到的数据包进行ADPCM解码,以DMA方式通过I²S总线发送给UDA1341语音模块进行播放。另外,可以将录制的PCM数据经过ADPCM压缩后上传至上位机进行保存。除了上位机可以对下位机进行音量和均衡器的调节外,各个下位机也可以通过键盘进行个性化的控制,并且通过TFT彩色液晶显示播放的状态。实验结果表明,本系统实现了局域网内的语音实时录放。

In the paper,a real-time audio player based on the ARM7 and the Ethernet is designed.The hosts broadcast audio packets coded by ADPCM to each node in LAN.The node decodes the ADPCM packets,then transfers the PCM datas to UDA1341 audio module for playback through the I²S bus in the type of DMA.In addition,the recorded PCM can be compressed by ADPCM,then upload to the host for save.Not only the host computer could adjust the volume and EQ,each node can also adjust the items by the keyboard.Otherwise,TFT color liquid crystal can display the various states of the system.The practice results show that the system can process the real-time audio in the LAN well.