zhongjile

说明：  下面的程序利用友元函数求两点间的距离。请你将有关的程序补充完整，并总结为什么这里要用友元函数来求两点间的距离。(using friend to get the result.)

矩阵键盘密码锁+简易计算器，C52的单片机平台，C语言开发，适用于初学学习。(Matrix keyboard lock+ simple calculator, C52 MCU platform, C language development, suitable for beginners to learn.)

基于STM32的双串口通信程序，能实现两个串口的收发，程序默认采用串口2接收数据，串口1发送(Based on the STM32 dual serial communication procedures, can achieve two serial transceivers, the program defaults to the serial port 2 receives the data, send the serial port 1)

利用ULN2003A进行驱动，产生PWM波，里边有照片，可供参考，通过本例程了解PWM 的基本原理和使用 (#include <reg52.h> unsigned char timer1 sbit PWM=P1^2 void system_Ini() { TMOD|= 0x11 //PWM TH1 = 0xfe //11.0592 TL1 = 0x33 TR1 = 1 IE =0x8A } main() { system_Ini() while(1) { if(timer1>100) timer1=0 if(timer1<30) PWM=0 else PWM=1 } )

1、万年历，2、时间，3、星期，4、温度显示，(1, million years 历, 2, hours, 3, star period, 4, temperature 显示,)

学习电子电路，很好的参考资料，可以学到很多东西。(Learning electronic circuits, a very good reference, you can learn a lot.)

说明：  四方的通信管理机程序，绝对的超值，很多规约的处理，101 103 103 104 CDT DNP SC1801 CSC2000等，千万别走漏风声啊，(sifang processs protel control center )

单片机一线通讯,控制4个数码管显示.里面有汇编和C语言源码(Single-chip front-line communications, control 4 digital display. There are assembly and C language source code)

本文以霍尔茨(HOLZER)法作为船舶轴系扭转振动的计算方法，着重研究了船舶轴系自由扭振的计算与分析，并对轴系扭振产生原因进行了分析，提出了一系列减振方法，以保证船舶动力装置的安全正常运行。(In this paper, Holtz (HOLZER) Act as the ship shafting torsional vibration calculation methods, focusing on the calculation and analysis of ship shafting torsional vibration of freedom, and the shaft torsional vibration causes analyzed, proposed a series of less vibration methods to ensure the safety of the ship s power plant running.)

PIC （PIC16F886） 做的简单频率计 用TMR0定时1s，将待测信号从T1CKI脚输入，用TMR1进行计数，读出TMR1H，TMR1L的值就是频率 单片机：PIC16F886 显示：LCD1602 编程语言：PIC C 附Proteus仿真。(PIC (PIC16F886) to do a simple frequency counter TMR0 timer with 1s, the test signal input pin from T1CKI with TMR1 count, read TMR1H, TMR1L value is the frequency of the microcontroller: PIC16F886 display: LCD1602 with Proteus simulation.)