stc89c5a16s2单片机的ad模数转换，使用扫描法，可同时转换8路模拟信号-stc89c5a16s2 ad microcontroller analog-digital conversion, using the scanning method, which can convert 8 analog signals

AD采集电压，查表转换成厚度值，并显示到数码管上。-AD Acquisition voltage, the thickness of the value of look-up table to convert, and display on the digital control.

We have to design a second order Butterworth filter having a sampling frequency of 20 kHz and -3db cut of frequency at 2 kHz in visual C. Only low frequency signals can pass through this filter and the signals having the frequency higher than frequen

C代码实现的GSM全速率语音编解码，GSM系统是一种全数字系统，话音和其它信号都要进行数字化处理，因此移动台首先要将语音信号转换成模拟电信号，以及其反变换，移动台再把这模拟电信号转换成13Kbit/s的数字信号，用于无线传输-GSM full rate speech code-decode.GSM system is a full digital system, voice and other signals to digital processing, so the mobile statio