905--

1、ADO技术 2、用对话框显示图片 3、对话框动态伸展(1, ADO technology 2, with a dialog box is displayed pictures 3, the dialog dynamic extension)

滤波器广泛应用于数字信号处理、通信、自动控制领域,但设计可变宽频带有源滤波器则比较困难。利用单片机控制参数可编程的双二阶通用开关电容有源滤波器,精确设置有源滤波器的中心频率f，品质因数Q及有源滤波器的工作方式。本系统主要分为两个部分:即程控滤波器和程控放大器。程控放大器电压增益为40dB，通过单片机控制DA进行分压，可精确实现要求的10dB步进，误差小于0.5 ，通带为100Hz-500KHz，输入电压峰－峰值范围为10mV，在输入范围内无明显失真。由MAX264为核心的滤波器，可设置为高通、低通滤波器。通过单片机直接给出控制频率，使-3dB截止频率在1KHz-20KHz内可调，步进1KHz，误差小于1 。整个系统以52单片机为控制核心，电路简单，性能稳定，且具有较高精度，滤波参数调节通过单片机控制，较为方便。(Filters are widely used in digital signal processing, communications, automatic control area, but the design variable wideband active filter is more difficult. Control parameters using single-chip programmable universal switched-capacitor biquad active filter, active filter accurately set the center frequency f, quality factor Q and the active filter works. The system is mainly divided into two parts: the program-controlled filters and programmable amplifiers. Programmable amplifier voltage gain of 40dB, the DA through the partial pressure of single-chip control, can accurately achieve the required 10dB step, the error is less than 0.5 , passband to 100Hz-500KHz, input voltage peak- the range of 10mV, the input range no significant distortion. By the MAX264 as the core of filter can be set to high pass, low pass filter. Given directly by the microcontroller controls the frequency, the-3dB cutoff frequency at 1KHz-20KHz adjustable, step 1KHz, error is less than 1 . The entire system for)

详细描述了基于ADSP-21262的数字压限器的设计，给出了算法流程，可以根据其描述进行实现(A detailed description of the ADSP-21262 digital limiter based design, flow chart of the algorithm is given, according to the description of implementation)

STM32F407信号发生器输入一个正弦波，AD采样，DA输出，系统频率应该是输入的波形的频率的10倍以上保证输出波形的完整性，系统的输出频率可以使用示波器测试出。(Stm32f407 signal generator input a sine wave, AD sampling, Da output and system frequency should is 10 times the frequency of the input waveform to guarantee that the above output waveform of integrity, the output frequency of the system can use oscilloscope to test out. )

通过反转法循环扫描矩阵键盘，并通过数码管显示数据(By inversion method cyclic scan matrix keyboard, and through the digital display data)

用共阴极数码管做的密码锁,可修改密码 ( this is a codelock )

说明：  stc系列单片机的开发例程 各个模块都跳通过了 开发环境是 keil3(STC series MCU development routines in all modules jump through the development environment is keil3)

合泰单片机，大学生单片机竞赛组委会提供的，必须使用该单片机开发的作品才能评选(holtek mcu )

实现单片机与LABVIEW的串口通信。单片机部分的上载程序，只需用LABVIEW构建一个简单的输入与输出指令界面(LABVIEW MCU and serial communication. Single-chip part of the upload process, just use LABVIEW build a simple command interface, input and output)

DMM-32x-AT 板卡AD 测试程序(program for AD test of board DMM-32x-AT)