On sales of surveillance systems, monitoring systems on sale

RN8209计量芯片，采集电压电流，计算电量，有功功率，无功功率，支持防窃电功能，rn8209串口通信，原厂提供的代码，可以下载直接使用。

详细介绍了matlab中声声音录制、读写与播放的语句描述 (Described in detail the description of Matlab acoustic sound recording the statement, read and write and play)

说明：  matpower 7.0，需要请的自行下载(Matpower7.0, download on your own)

椭圆滤波器C程序和matlab的仿真m文件，根据matlab仿真设计椭圆滤波器参数，再编写C程序(C program of ellipsefilter)

采用比较浅显易懂的方式讲解了VC++里面怎样进行dll编程。(The use of relatively easy to understand way which explains how the VC++ dll programming.)

说明：  surfacique courant coupleur 3db

MPEG解码源代码。转载中国程序员网络，提供该代码。(MPEG decode)

八位LED时钟带调小时调分钟调 秒 ，配proteus仿真电路 C51源程序(Eight bit LED clock with adjustable hour to adjust minute to second, with Proteus simulation circuit C51 source program)

说明：  msp430单片机，M5310模组实现NB-Iot通信，对学习NB有帮助(MSp430 MCU and M5310 module realize NB-Iot communication, which is helpful for learning NB)

支持向量机在小波包去噪方法中的应用，小波包分解和svm相结合(Support vector machines in wavelet packet denoising of wavelet packet decomposition and combination svm)