【电子信息工程毕业设计 文献综述 开题报告】基于AT89C51单片机的噪声测量仪设计（可编辑）.doc

【电子信息工程毕业设计+文献综述+开题报告】基于AT89C51单片机的噪声测量仪设计 Noise Measurement Instrument Design Based on AT89C51 Abstract This paper introduces the design that noise measurement system based on AT89C51.This noise measurement instrument uses general AT89C51.The features are integration, high and strong processing functions, high reliability, simple system structure, inexpensive and easy to use. This paper gives the system hardware design and software design, and the simulation process and the result. This system has the characteristic that high accuracy, easy operation and strong practical applicability. This system’s overall design including the choices of amplifying circuit’s feedback circuit, V/F chip, eventually got the processing schemes of usability. The design’s noise measurement device is mainly composed of sensors that collect noise. The sensor is standing very body microphones. The current signal of microphone collected convert into the voltage signal after the amplifier amplification. The voltage signal convert into frequency signal after the V/F circuit. This frequency signal put into AT89C51 to process through the P3.7 pin. Finally, AT89C51 process the data and output. The LED digital display show the data. Keywords: noise measurement, magnifier, AT89C51, V/F conversion 目 录 摘要 Ⅲ Abstract Ⅳ 1 绪论 1 1.1 课题的来源 1 1.2 课题的意义 1 1.3 国内外发展现状 2 1.4 课题研究的主要内容 3 2 方案设计与总体设计 4 2.1 方案设计 4 2.2方案论证 4 2.3总体设计 5 2.3.1总体方案设计 5 2.3.2 系统硬件设计 5 2.3.3 系统软件设计 5 2.3.4 系统调试 5 2.3.5 系统完善和升级 6 3 硬件设计 7 3.1 传感器部分 7 3.1.1 驻极体话筒的工作原理 7 3.1.2 驻极体话筒与电路的接法 7 3.2 放大电路的设计计算 8 3.2.1 LM324放大器 8 3.2.2 运算放大器的负反馈电路 10 3.3 V/F变换电路的设计 12 3.3.1 电压-频率变换器芯片LM331 12 3.3.2 LM331压频变换器的原理 15 3.3.3 输入电压和输出频率的关系 15 3.4 单片机部分 17 3.4.1复位电路和晶振电路 17 3.5 数码管显示电路 19 3.6 串口驱动电路 20 4 软件设计 22 4.1 总流程图 22 4.2 各子模块说明 24 4.2.1 上位机模块 24 4.2.2 下位机模块 25 5 结论 28 参考文献 29 致谢 30 附录 31 附录