多年工作有关PCB绘图的总结，适合初学者学习

51单片机基础训练项目之会唱歌的单片机。本例使用普通有源蜂鸣器，通过控制单片机输出频率来达到“唱歌”的目的。着重训练初学者对IO管脚的认识。-51 MCU-based training program in the microcontroller will be singing. In this case the use of ordinary active buzzer, by controlling the microcontroller output frequency to achieve the " singing" objective. Focus on training for beginners to the IO pin awareness.

USB转lpt 68013 驱动方案 USB转lpt 68013 驱动方案-Lpt 68013 Driver USB to USB transfer program lpt 68013 driver program

基于AT89S52单片机的电子万年历设计制作的汇编程序-AT89S52-based single-chip design of the electronic calendar of the assembler

MCS-51单片机实用子程序库（3），WORD文档-MCS-51 microcontroller practical Subroutine Library (3), the Word document

程序包括的内容是常用的AD0809演示程序，读者可以很容易将此代码移植到自己的系统上。-Procedures, including the contents of the AD0809 is a commonly used presentation program, readers can easily transfer this code to your system.

T9 Text Input You can use this source code for input T9 Text Input(English)

关于SPLC501C的液晶编程，实现了中文菜单形式，可以参考-SPLC501C LCD on the programming and realized the Chinese menu form, they can refer to

很小很弱的51单片机的四字节BCD码转换程序不过很多课堂练习可以参考-very weak 51 SCM four byte BCD conversion but many can refer to classroom exercises

C51程序框架生成器，主要针对51系列单片机的C程序开发，提供相关寄存器、定时器、串行接口等初始化操作，生成C程序框架。程序中附带数模转换功能。-C51 process framework generator, mainly for the 51 series MCU C application development, to provide relevant registers, timers, serial interfaces such as initialization, generating C procedural framework. Program with digital-analog conversion.

目前市场上有很多语音录放系统，如录放音玩具、录音笔等，大多采用了单片机控制一个语音芯片，再接一个FLASH存储器的结构。单片机可以控制录放时间，选取特定时间段的播放以及单多声道的录放，容易通过改变外接存储FLASH改变录放时间。 我们做的是一个简单模型，只能录放。 只需要录音和放音时的外部 ROSC 端振荡电阻不同就能改变声音的录入和播放速度，录入的时间越短音质越好，录入的时间越长音质越差 它采用模拟量直接存贮技术，因此保真度高，音质好 -Currently on the market there is a lot of voice recording systems, such as sound recording toys, sound recording pens and so on, most of the single-chip microcomputer to control the use of a voice chip, making the structure of a FLASH memory. Single-chip microcomputer can control the playback time, select a specific period of time many of the players, as well as single-channel recording, easy to FLASH memory by changing the external playback time change. We make a simple model, only playback. Required only when the recording and playback-side oscillation of the external resistor ROSC will be able to change different recording and playback of sound speed, the shorter the time of admission, the better sound quality, longer recording sound worse using direct ana