AVR Atmega649程序，家用空调的室内机软件应用

Small RTOS 51 DP－51下载仿真实验仪上实现一个闹钟的源代码。-Small RTOS 51 DP-51 download simulation instrument to achieve an alarm clock source.

keil uVision3编译环境，51程序。-keil uVision3 build environment, 51 program.

SD卡驱动 SD_CARD_TIMEOUT 当一个SD卡的操作超出时限，将导致返回错误和该标记被置位 SD_CARD_EXIST 当卡槽内插入了合适的卡体，不管是什么卡，都会使该位被设置； SD_CARD_WRITE_PROTECT 当卡体的写保护开关被 LOCK 时，则该位被设置； SD_CARD_READY 当卡槽内的卡被正确识别，并可以随时访问时，则该位被设置； SD_CARD_DOOR_CLOSE 当卡槽的门（产品外壳上的挡板开关）关闭时，则该位被设置； SD_CARD_IS_SD 当卡槽内插入的是 SD 卡时，则该位被设置。 SD_CARD_IS_MMC 当卡槽内插入的是 MMC 卡时，则该位被设置； 注意：不要使用 0x80，免得和整数作逻辑运算时被误为负数。-err

单片机与FPGA控制128*64液晶显示程序，用总线方式控制

HID sample code for HOLTEK

LCD液晶显示器源码 keil c51 at89c51-LCD liquid crystal display source keil c51 at89c51

用8051实现的PS2协议的PC键盘，有详细注释-8051 with the realization of the agreement PS2 PC keyboard, a detailed Notes

pic单片机串口通信调试程序，单片机收到上位机命令后发送数据-Single-chip serial communication pic debugger, single-chip PC orders received after sending data

在51单片机下44780液晶显示块的编程实例。-Under 44,780 in the 51 single-chip LCD block programming examples.

在做项目（工程）的时候，我们经常要用到比较多的按键，而且IO 资源紧张， 于是我们就想方设法地在别的模块中节省IO 口，好不容易挤出一两个IO 口，却 发现仍然不够用，实在没办法了就添加一个IC 来扫键。一个IC 虽然价格不高， 但对于大批量生产而且产品利润低的厂家来说，这是一笔不菲的开支! 那，我们能不能想到比较好的扫键方法：用最少的IO 口，扫最多的键？可以吗？-Doing the project (engineering), we often use the relatively large number of keys, and the IO resource constraints, so we are trying to save in another module IO ports, finally out of one or two IO ports, only to find is still not enough there is really no other way to add an IC to sweep on the keys. Although the price of an IC is not high, but low profits, high-volume production and product manufacturers, this is spending a lot of money! That, we can not think of a better scan key method: with a minimum of IO ports, scan Most of the keys? OK?