介绍一种基于单片机控制的数控直流电流源。系统以AT89S52单片机为控制核心，由V/I转换电路、DA转换、AD转换等模块组成。通过按键设定电流值，并在LCD上同步显示预设值，利用模拟闭环控制原理实现V/I转换功能，采样电阻两端的电压值送给A/D转换电路，经单片机换算成实际输出电流值，并利用LCD显示，供用户参考。经测试，本系统稳定性好、精度较高、操作简单、人机界面友好。在科学研究和设备生产中，能够广泛应用到这种可靠性高、操作简单的数控电流源，不仅能够提高设备的性能，同时能够缩短研发周期，本系统具有较高的实用性。
上传时间： 2013-11-06
上传用户：csgcd001
一、 main.c(35): warning: #128-D: loop is not reachable from preceding code 原因，前面有一个while(1){ …….} 二、 main.c(54): warning: #1-D: last line of file ends without a newline 少了一个回车在}之后
上传时间： 2014-12-26
上传用户：sjb555
何谓单片机 一台能够工作的计算机要有这样几个部份构成：CPU（进行运算、控制）、RAM（数据存储）、ROM（程序存储）、输入/输出设备（例如：串行口、并行输出口等）。在个人计算机上这些部份被分成若干块芯片，安装一个称之为主板的印刷线路板上。而在单片机中，这些部份，全部被做到一块集成电路芯片中了，所以就称为单片（单芯片）机，而且有一些单片机中除了上述部份外，还集成了其它部份如A/D，D/A等。
标签： 51单片机
上传时间： 2013-12-18
上传用户：xuanchangri
Analog Inputs and Outputs in an S7 PLC are represented in the PLC as a 16-bit integer. Over the nominal span of the analog input or output, the value of this integer will range between - 27648 and +27648. However, it is easier to use the analog values if they are scaled to the same units and ranges as the process being controlled. This applications tip describes methods for scaling analog values to and from engineering units.
上传时间： 2013-11-17
上传用户：3294322651
摘要:中国大洋协会(coM卫A)多金属结核中试采矿系统的测控实验系统为采矿系统的虚拟研究提 供了一个高性能的模拟实验平台。本文以采用AT9054434型AVR单片机设计开发的模拟集矿机精确 测控系统为例，介绍了AVR单片机的特点和工作机理，详细阐述了基于AVR单片机的精确驱动控制 系统的设计与开发方法，具有一定的参考和推广价值。
上传时间： 2013-11-30
上传用户：破晓sunshine
数字控制的交流调速系统所选用的微处理器、功率器件及产生PWM波的方法是影响交流调速系统性能好坏的直接因素。在介绍了正弦脉宽调制(SPWM)技术的基础上，设计了一种以8098单片机作为控制器，以智能功率模块IPM为开关器件的变频调速系统。通过软件编程，产生正弦脉冲宽度调制波形来控制绝缘栅双极晶体管的导通和关断，从而达到控制异步电动机转速的目的。实验结果表明，该系统可调频率调电压，稳定度高，调速范围宽，具有较强的实用价值 Abstract: AC variable speed with digital control systems used microprocessors， power devices and generate PWM wave is the direct factors of affecting the performance AC speed regulation system. On the basis of introducing the sinusoidal pulse width modulation (SPWM) technology，this paper designed variable speed system which used 8098 as a controller， intelligent power module IPM as switching device. Through software programming， resulting in sinusoidal pulse width modulation waveform to control the insulated gate bipolar transistor turn on and off， so as to achieve the purpose of speed control of induction motors. Experimental results show that the system can adjust frequency modulation voltage， high stability， wide speed range， has a strong practical value.
上传时间： 2013-11-14
上传用户：ynwbosss
在理论分析循环码编码和译码基本原理的基础上，提出了基于单片机系统的(24，16)循环码软件实现编码、译码的方案。仿真结果表明(24，16)循环码能有效地克服来自通讯信道的干扰，保证数据通信的可靠及系统的稳定，使误码率大幅度降低。本论文对(24，16)循环码的研究结果表明，可以有效地降低错误概率和提高系统的吞吐量，实现纠错仅需要在接收端增加有限的存储空间和计算复杂度，具有一定的实用价值。 Abstract: Based on analyzing the theory of encoding and decoding of cyclic code， this paper showed the schemes of encoding and decoding of(24，16)cyclic code by the software and based on microcontroller. Simulation results show that using (24，16) cyclic codes can effectively overcome the interference from communication channel， ensure the reliability and stability of data communication systems， and reduce the bit error rate greatly. The results of this paper show that by using the (24，16) cyclic code， the error rate can be reduced and the system throughput can be improved. Meanwhile， the system only needs to enlarge limited storage space and computation the complexity at the receiving end to realize error correction. Thus the (24，16) cyclic code has a practical value.
上传时间： 2013-11-09
上传用户：gaoliangncepu
利用单片机具有的智能程序控制的特点，设计了基于STC89C52单片机的"二极管特性测试器"，可对二极管一般特性进行快速测试。通过稳定线性电流源给二极管加载恒定电流，然后由高精度模数转换器测试其压降，以此为基础可判断二极管好坏、检测二极管极性和测试二极管伏安特性等，避免了用万用表测试只能测得极性而不知其特性这一缺点。可用于电子设计制作过程中对二极管进行快速测试，以确定被测二极管是否满足电路的设计要求。 Abstract: By making good use of the intelligent control function of the Micro Controller Unit (MCU)， the diode trait tester was designed based on the STC89C52，which could be used to test the trait of a diode rapidly. By loading constant current to diode through the stable linear current source， and measuring the voltage drop of the diode by high-precision analogue-to-digital converter (ADC)， it can judge whether the diode is good or not， distinguish the polarity of the diode， and test the trait that the diode， which can avoid the fault of using a multimeter can only measure the polarity but not the trait. This device can be used to test the trait of a diode quickly，and to make sure that whether a diode can be used in the electronic design or not.
上传时间： 2013-11-13
上传用户：assef
Designing read/write device (RWD) units for industrial RF-Identification applications is strongly facilitated by the NXP Semiconductors HITAG Reader Chip HTRC110. All needed function blocks, like the antenna driver, modulator demodulator and antenna diagnosis unit, are integrated in the HTRC110. Therefore only a minimum number of additional passive components are required for a complete RWD. This Application Note describes how to design an industrial RF-Identification system with the HTRC110. The major focus is dimensioning of the antenna, all other external components including clock and power supply, as well as the demodulation principle and its implementatio
上传时间： 2013-10-22
上传用户：zhengjian
针对科研实验中对拉压千斤顶加载过程控制的需要，采用ATmega128单片机控制步进电机进而实现对执行系统的电动泵站实行自动控制。对力和位移的数据采集与处理及用步进电机控制电动泵站手柄的技术细节作了重点描述。通过单片机的A/D变换器对AMP放大模块采集的电桥信号作量化处理，千斤顶的操控手柄位置依电动油泵阀门开启的方向和大小作若干定位，单片机根据力或位移传感器信号，实时控制步进电机驱动手柄旋转到相应操控位置。 Abstract: This article describes the use of ATmega128 AVR microcontroller series of DBS electric pumping stations and QF100/200 separate twoway hydraulic jack to automate the process of manipulating the work of the technical content. Articles on force and displacement data acquisition and processing， and stepper motor control electric pump with the handle of the key technical details were described. Through the MCU’s A / D converter module is collected on the AMP amplification quantify the signal bridge， jack handle position control valve opening according to the direction of electric pumps for a number of positioning and size of the microcontroller based on force or displacement sensor signals， real-time control stepper motor drive control handle rotate to the appropriate location.
上传时间： 2014-01-16
上传用户：hasan2015
