按键检测超精简实用程序

一个arm7开发板上的beep蜂鸣器实验程序，此程序用c语言编写。-a arm7 development board buzzer beep experimental procedure, this procedure using c language.

详细记录了实现w5500实现UDP功能测试的原始方法，代码具有代表性的说明了w5500的使用方法。 本方案给予STM32F429discovery。使用spi1接口作为w5500控制口。 驱动电压可以为3V也可以为5V。 更具测试版选择。 

鼎力推荐！本程序是基于嵌入式LUNUX系统开发的源程序代码，所有程序采用C语言进行编写，是学习、开发嵌入式LUNUX系统不可多得的参考资料。-strongly recommended! This procedure is based on the embedded system development LUNUX the source code, all the procedures used for the preparation of C language, learning, the development of embedded systems LUNUX rare reference.

电梯门禁系统：包括系统原理图，通信流程图和C语言源程序 AT89C52控制H6152读卡器读写Mifare射频卡并通过CAN总线连接系统主机，CAN总线控制器为SJA1000，收发器为P82C250.-Door guard system of the lift, Including systematic principle picture and source program . AT89C52 control H6152 card reader to write Mifare radio frequency nip and connect the systematic host computer through CAN bus to read, CAN bus controller is SJA1000, the transceiver is P82C250.

在s3c44b0x运行的俄罗斯方块游戏 解压密码：arm520-A Russion Diamonds Game run at s3c44b0x. decompress password:arm520

本源程序实现通过4*4键盘输入数据，在液晶上实时显示。并实现和PC间的信息交换-Realize the source code through the 4* 4 keyboard input data, in real-time display on the LCD. And the realization and the exchange of information between PC

Part IV In part II we discussed the conversion of binary numbers into decimal digits. It is sometimes useful to build circuits that use this method of representing decimal numbers, in which each decimal digit is represented using four bits. This scheme is known as the binary coded decimal (BCD) representation. As an example, the decimal value 59 is encoded in BCD form as 0101 1001. You are to design a circuit that adds two BCD digits. The inputs to the circuit are BCD numbers A and B, plus a carry-in, cin. The output should be a two-digit BCD sum S1S0. Note that the largest sum that needs to be handled by this circuit is S

本实验将实现如下功能：开机的时候先检测字库，然后检测SD卡是否存在，如果SD卡存在，则开始查找SD卡根目录下的PICTURE文件夹，如果找到则显示该文件夹下面的图片文件（支持bmp、jpg、jpeg或gif格式），循环显示，通过按KEY0和KEY2可以快速浏览下一张和上一张，KEY_UP按键用于暂停/继续播放，DS1用于指示当前是否处于暂停状态。如果未找到PICTURE文件夹/任何图片文件，则提示错误。同样我们也是用DS0来指示程序正在运行。

使用89S52设计的电子钟，C51 编写，本例没有使用1302等时钟芯片，但本例完全具有时钟芯片的功能。比如基本的年月日，时分秒和星期功能，而且还有平闰年的天数自动补偿。由于采用的是全软件算法，时钟误差较大，采用高质量晶振可以减少误差。本例重在培养与训练初学者对C51的学习。-89S52 designed using an electronic clock, C51 preparation, in this case did not use 1302 clock chip, etc., but in this case complete with a clock chip functions. For example the basic date, time, and every second week of features, but also the number of days flat leap automatic compensation. As a result of the full software algorithms, the clock error of greater use of high-quality crystal can reduce the error. In this case focuses on training and training for beginners to learn on the C51.

arm3000的键盘和led驱动的源代码-arm3000 the keyboard and led driver source code