第9题 数字化语音存储与回放系统

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数字化语音存储与回放系统(E题) 12组：殷凯 李健 李文超

2015年8月1日 数字化语音存储与回放系统（E题） 一、基础部分 ①.放大器1的增益为46dB，放大器2的增益为40dB，增益均可调； ②.带通滤波器：通带为300Hz ~ 3.4kHz； ③.ADC：采样频率fs=8kHz，字长=8位； ④.语音存储时间≥10秒； ⑤.DAC：变换频率fc=8kHz，字长=8位； ⑥.回放语音质量良好。 二、发挥部分 ①.减少系统噪声电平，增加自动音量控制功能； ②.语音存储时间增加到20秒以上； ③.在原有存储器不变的前提出下，提高语音存储时间； ④.其它。 三、评分标准

任务 项目 得分

基本要求 方案设计与论证、理论分析与计算 30 测试方法与数据、对测试结果的分析 20 实际制作完成情况 50

发挥部分 完成发挥部分第①项 15 完成发挥部分第②项 5 完成发挥部分第③项 15 完成发挥部分第④项 15 数字化语音存储与回放系统（E题） 摘要 本设计基于增强型STM32F103ZET6单片机，实现数字化语音存储与回放。语音信号通过驻极体话筒采样后进行放大，经过通频带为300Hz-3.4kHz的带通滤波器进行滤波，通过AGC电路实现自动音量控制，送入单片机内部进行ADC采样并存入内部FLASH存储器中。录制完成后语音数据再经过单片机内部DAC输出为模拟信号，并再次通过带通滤波器滤波后对其进行功率放大，保证信号回放质量。为提高存储器利用率，本设计采用ADPCM算法，延长语音存储时间，经测试可达30秒。本系统的创新点在于使用单个按键简化控制逻辑，并通过指示灯实时表示系统当前的工作状态，简单直观，易于使用。

关键词 STM32 带通滤波器 ADPCM算法 LM386

Abstract This design is based on the enhanced STM32F103ZET6 microcontroller, digital voice storage and playback. Electret microphone samplings were conducted after amplification by speech signal, through the pass band of 300Hz-3.4kHz bandpass filter with the filter, the AGC circuit realization of automatic volume control, into the internal microcontroller ADC sampling and stored in internal flash memory. After recording the speech data, the DAC output is analog signal, and the power amplifier is amplified by the filter with the filter, and the signal quality is guaranteed. To improve memory utilization, this design uses ADPCM algorithm to extend the voice storage time, the test can reach 30 seconds. The innovative point of this system is to simplify the control logic by using a single key, and it is easy to use in real time, and it is simple and intuitive, and it is easy to use.

Keywords STM32 Band Pass Filter ADPCM Algorithm LM386 目录 1 方案选择与比较 ........................................................................................................................................... 1 1.1 主控制器的选择与比较 ....................................................................................................................... 1 1.2 语音信号采集的选择与比较 ............................................................................................................... 1 1.3 带通滤波器的选择与比较 ................................................................................................................... 1 1.4 A/D和D/A转换电路的选择与比较 .................................................................................................... 1 1.5存储器的选择与比较 ............................................................................................................................ 2 2 总体设计 ....................................................................................................................................................... 2 3 硬件设计 ....................................................................................................................................................... 2 3.1 语音输入 ............................................................................................................................................... 2 3.2 放大电路 ............................................................................................................................................... 3 3.3 带通滤波器 ........................................................................................................................................... 3 4 软件设计 ....................................................................................................................................................... 4 4.1 主程序设计 ........................................................................................................................................... 4 4.2 AGC功能实现 ........................................................................................................................................ 4 4.3 存储空间分配 ....................................................................................................................................... 5 5 系统测试与结果 ........................................................................................................................................... 5 5.1 测试仪器 ............................................................................................................................................... 5 5.2 测试方法 ............................................................................................................................................... 5 5.3 测试结果 ............................................................................................................................................... 5 5.3.1 基本要求的测试与结果 ............................................................................................................... 5 5.3.2 扩展要求的测试与结果 ............................................................................................................... 5 6 总结与体会 ................................................................................................................................................... 6 7 参考文献 ....................................................................................................................................................... 6 附录 ................................................................................................................................................................... 6 程序清单 ....................................................................................................................................................... 6 程序框图 ..................................................................................................................................................... 10