电容、电阻参数单片机测试系统的设计

单片机原理及应用课程设计报告设计课题：电容、电阻参数单片机测试系统的设计专业班级：电气工程及其自动化6班学生姓名：崔亮指导教师：徐建2015年6月单片机原理及应用课程设计报告-1-目录目录·······························································································11设计任务书·····················································································21.1基本设计要求·········································································21.2选作项目···············································································22设计阐明························································································32.1设计内容················································································32.2设计要求················································································32.3设备及工作环境·······································································33系统方案整体设计············································································43.1设计思路···············································································43.2系统整体框图·········································································44硬件设计························································································54.1系统硬件设计·········································································54.1.1按键电路设计·········································错误!未定义书签。4.1.2LCD显示器·····································································54.1.3ADC0804转换…………………………………………………………64.2系统工作原理论述···································································75软件设计························································································75.1分析论证···············································································75.1.1显示模块·······································································85.1.2产生脉冲模块·································································85.1.3转换模块·······································································85.1.4启动/暂停，复位模块······················································95.1.5整体功效·······································································95.2程序流程图············································································95.3程序清单················································································96调试过程及分析·······················································错误!未定义书签。7设计总结······················································································20参考文献····················································································21单片机原理及应用课程设计报告-2-1设计任务书1.1基本设计要求（1）在综合单片机实验箱的硬件结构上编写软件完成设计。（2）程序的首地址应使目标机可以直接运行，即从0000H开端。在主程序的开端部分必须设置一个合适的栈底。程序放置的地址须持续且靠前，不要在中间留下大批的空间地址，以使目标机可以应用较少的硬件资源。（3）在液晶显示屏上显示测量的电阻电容，第一行显示measures第二行显示测的的值，如R=00.0KΩ或者C=00.00uF（4）在电路中设定三个按键一个是换电阻的按键，其余分别为测电容和测电阻时的按键，当按下测电阻键时，显示相应的电阻值，当按下电容值时显示测得的电容值（5）软件设计必须应用8052片内定时器，采用定时中断结构，可以采用软件中断的延时法。1.2选作项目1、另设三个键，分别作液晶显示器的调校。2、可以通过硬件电路，编写相应的软件程序，实现显示字幕的左移，右移等功能，本程序没有3、同时也可以设置相应的量程来设计，本程序有相应的硬件电路，但软件读者可以自己编写单片机原理及应用课程设计报告-3-2设计阐明2.1设计内容用ZY15MCU12BD型综合单片机实验箱及串口电路设计实现显示时间并能够调校时间的时钟，还能够实现秒表的启动/暂停，复位功能。说明设计中包含的内容2.2设计要求（1）在ZY15MCU12BD型综合单片机实验箱的硬件结构上编写软件完成设计。（2）程序的首地址应使目标机可以直接运行，即从0000H开端。在主程序的开端部分必须设置一个合适的栈底。程序放置的地址须持续且靠前，不要在中间留下大批的空间地址，以使目标机可以应用较少的硬件资源。（3）在液晶显示屏上显示测量的电阻电容，第一行显示measures第二行显示测的的值，如R=00.0K或者C=00.00uF（4）在电路中设定三个按键一个是换电阻的按键，其余分别为测电容和测电阻时的按键，当按下测电阻键时，显示相应的电阻值，当按下电容值时显示测得的电容值（5）软件设计必须应用8052片内定时器，采用定时中断结构，可以采用软件中断的延时法。（6）上机调试程序。（7）写出设计报告。2.3设备及工作环境(1)硬件：盘算机一台、ZY15MCU12BD型综合单片机实验箱一台、通信电缆一根。(2)软件：Windows操纵系统、KeilC51软件。单片机原理及应用课程设计报告-4-3系统方案整体设计3.1设计思路或设计方案论证对电阻的测量，可将待测电阻与一标准电阻串联后接在+5V的电源上，根据串联分压原理，利用ADC测定电阻两端电压后，即可得到其阻值。对电容的测量，可将其与已知阻值的电阻RA和RB组成基于NE555的多谐振荡器如下页图。其产生的方波信号频率为：)R2C(R1.44fBA故通过测定方波信号的频率可以比较精确的测定C的值。测定方波信号频率的方法，。测量频率有测频法和测周法两种。(1)测频法，利用外部电平变化引发的外部中断，测算1s内的波数，从而实现对频率的测定；(2)测周法，通过测算某两次电平变化引发的中断之间的时间，实现对频率的测定。简而言之，测频法是直接根据定义测定频率，测周法是通过测定周期间接测定频率。理论上，测频法适用于较高频率的测量，测周法适用于较低频率的测量。经过调校，在测量低频信号时，本项目中测频法精度已高于测周法，故舍弃测周法，全量程采用测频法。3.2系统整体框图单片机原理及应用课程设计报告-5-图1系统整体框图4硬件设计4.1系统硬件设计4.1.1按键电路设计按键是实现人机对话的比较直观的接口，可以通过按键实现人们想让单片机做的不同的工作。键盘是一组按键的集合，键是一种常开型开关，平时按键的两个触点处于断开状态，按下键是它们闭合。键盘分编码键盘和非编码键盘，案件的识别由专用的硬件译码实现，并能产生键编号或键值的称为编码键盘，而缺少这种键盘编码电路要靠自编软件识别的称为非编码键盘。在单片机组成的电路系统及智能化仪器中，用的更多的是非编码键盘。就是一种比较典型的按键电路，在按键没有按下的时候，输出的是高电平，当按键按下去的时候，输出的低电平4.1.2LCD显示器1602液晶也叫1602字符型液晶它是一种专门用来显示字母、数字、符号等的点阵型液晶模块它有若干个5X7或者5X11等点阵字符位组成，每个点阵字符位都可以显示一个字符。每位之间有一个点距的间隔每行之间也有间隔起到了字符间距和行间距的作用，正因为如此所以他不能显示图形（用自定义CGRAM，显示效果也不好）n1602LCD是指显示的内容为16X2,即可以显示两行，每行16个字符液晶模块（显示字符和数字）。n目前市面上字符液晶绝大多数是基于HD44780液晶芯片的，控制原理是完全相同的，因此基于ADC0804AT89S52输入电阻R复位电路开关控制NE555输入电容单片机原理及应用课程设计报告-6-HD44780写的控制程序可以很方便地应用于市面上大部分的字符型液晶。+5V电压，对比度可调内含复位电路提供各种控制命令,如：清屏、字符闪烁、光标闪烁、显示移位等多种功能有80字节显示数据存储器DDRAM内建有192个5X7点阵的字型的字符发生器CGROM8个可由用户自定义的5X7的字符发生器CGRAM电压，对比度可调内含复位电路提供各种控制命令,如：清屏、字符闪烁、光标闪烁、显示移位等多种功能有80字节显示数据存储器DDRAM内建有192个5X7点阵的字型的字符发生器CGROM8个可由用户自定义的5X7的字符发生器CGRAM4.1.3ADC0804转换ADC0804是一个8位CMOS型逐次比较式A/D转换器，具有三态锁存输出功能，最短转换时间为100us，CS:片选信号，低电平有效；RD：外部读取转换结果的控制信号，当RD为高电平时，DB0-DB7为高阻态；当RD为低电平时，数据才会通过DB0-DB7输出；WR:A/D转换器启动控制信号，当WR由高电平变为低电平时，转换器被清零，当WR由低电平变为高电平时，A/D转换正式开始；CLKIN和CLKR:时钟输入端，在ADC0804片内有