5l 系列单片机为许多控制提供了高度灵活和低成本的解决办法。充分利用他的片内资源，即可在较少外围电路的情况下构 成功能完善的超声波测距系统...

介绍了用RS-232串口进行开发的过程，对于刚涉及串口编程的开发人员有一定帮助-Introduction by RS-232 serial port to carry out development process, for serial programming just related to the development of staff has a certain extent, help

16位元led等电流驱动器mbi5024驱动，-Led, such as 16-bit current driver mbi5024 drive,

SPI是一个环形总线结构，由ss（cs）、sck、sdi、sdo构成，其时序其实很简单，主要是在sck的控制下，两个双向移位寄存器进行数据交换。 假设下面的8位寄存器装的是待发送的数据10101010，上升沿发送、下降沿接收、高位先发送。 那么第一个上升沿来的时候 数据将会是sdo=1；寄存器=0101010x。下降沿到来的时候，sdi上的电平将所存到寄存器中去，那么这时寄存器=0101010sdi，这样在8个时钟脉冲以后，两个寄存器的内容互相交换一次。这样就完成里一个spi时序。 -SPI bus is a ring structure, by ss (cs), sck, sdi, sdo composition, its timing is actually very simple, mainly under the control of the sck and two bi-directional shift register for data exchange. Assuming the following 8-bit register is loaded to send the data to be 10,101,010, rising to send, receive falling edge, high first sent. Well, the first rising edge to the time data will be sdo = 1 register = 0101010x. Falling edge comes, sdi on the level will be stored to the register, then register at this time = 0101010sdi, so 8 clock pulse later, the contents of two registers to exchange time. This will be completed in a spi timing.

低电压检测. A口低8位接键盘列线，键盘行线接VDDIO；B口高8位接LED // 按K1键 低电压为2.4v // 按K2键 低电压2.8v // 按K3键 低电压3.2v // 按K4键 低电压为3.6v

FreeRTOS，这个比 Real Time Linux 和 eCos 更小的实时操作系统，并且你也不用为这两个大的操作系统弄得头大了。FreeRTOS是一个非常小的实时操作系统，它包含有一个实时的内核及一个内核调制程序。它支持的单片机有 Philips ARM7, TI MSP430, Renesas (Hitachi) H8/S, Atmel AVR, Motorola/Freescale HCS12, Motorola/Freescale ColdFire, 及其他8051的单片机--FreeRTOS, an OS smaller than Real Time Linux and eCos. It is a very small real time operating system. It includes a real time kernel and a kernel configuration program.Its supported SCMs include Philips ARM7, TI MSP430, Renesas (Hitachi) H8/S, Atmel AVR, Motorola/Freescale HCS12, Motorola/Freescale ColdFire, and other 8051 SCMs.

单片机C51串口中断接收和发送测试例程可以用来测试51单片机的中断接收 //和查询发送，另外我觉得发送没有必要用中断，因为程序的开销是一样的 -80C51 Serial interrupted receive and send test routines can be used to test 51 MCU interrupt reception// Send inquiries and, I also think that this is not necessary for discontinued because the process is the same as the overhead

程序详细功能介绍： * 利用AT89S51单片机的P0端口的P0.0－P0.7连接到一个共阳数码管的a－h的笔段上， * 数码管的公共端通过三极管8550选通。在数码管上循环显示0－9数字，显示时间的间隔可通过修改延时程序。 -Procedures detailed functional Introduction:* use AT89S51 MCU port P0 is connected to P0.0-P0.7 Yang a total digital control of the a-h T segment,* digital tube through the public side-gated transistor 8550. In the digital control on the circulation figures 0-9 show, indicating the time interval may be delayed by modifying the procedures.

一个小型的数控电源的源码，采用DAC0832进行转换，实现0-12V的精度为0.1的步进调压。-NC a small power source, using the conversion DAC0832, 0-12V realize the accuracy of the stepper regulator 0.1.

用C51编的温度控制的PID算法适用性强方便移植-with C51 series of PID temperature control algorithm to facilitate transplantation 3DMECAD

c51 是经典的单片机，简单，精通51单片机，在学习其他的单片机 很易上手-C51 is a classic single-chip, simple, fluent in 51 single-chip, single-chip microcomputer in the learning of other very易上手