基于单片机的简易函数信号发生器

1、创新性实验研究报告实验项目名称简易函数信号发生器一、实验摘要用AT89C51单片机采用程序设计方法构成的波形发生器，可产生方波、三角波、正 弦波，再通过DA转换器DAC0832等数字信号转换成模拟信号，并通过LM3241成运放把 信号放大，通过示波器将波形显示在屏幕上。波形的周期可用程序改变，此设计具有线 路简单、结构紧凑、性能优越等特点。通过仿真测试，其性能指标达到了设计要求。并 进行实际焊接电路板，进行波形测试，均达到了实验目的。、实验目的1、进行硬件电路设计。2、编写程序，并进行程序测试。3、利用单片机采用软件设计方法产生三种波形。4、焊接电路，将程序下载到单片机，并用示波器对输出程序进

2、行测试。三、实验场地及仪器、设备和材料：实验场地：电子技术实验室。仪器、设备和材料：双通道数字示波器、 AT89C52II片机、DAC0832 LM324电脑、 杜邦线、洞洞板、电烙铁等。四、实验内容1、实验原理数字信号可以通过数/模转换器转换成模拟信号，因此可通过产生数字信号再转换成 模拟信号的方法来获得所需要的波形。89C51单片机本身就是一个完整的微型计算机，具有组成微型计算机的各部分部件：中央处理器CPU随机存取存储器RAM只读存储器ROM I/O接口电路、定时器/计数器以及串行通讯接口等，只要将89C51再配置键盘及其接口、 显示器及其接口、数模转换及波形输出、指示灯及其接口等四部分

3、，即可构成所需的波 形发生器，具信号发生器构成原理框图如下图所示。滤波放大电路将波形输出出来2、实验内容1、运用keil软件对程序进行编写，运行程序，并进行程序修改2、运用protues软件进行硬件电路仿真设计。3、将程序下载到仿真单片机中，并观测输出波形。4、对程序进行修改，再次运行仿真软件，直到输出理想的波形。5、仿照仿真软件进行硬件电路的焊接。6、将程序下载到单片机，并用示波器测试输出波形。7、对程序进行修改，直到输出满意的波形为止。3、实验步骤1、首先打开keil软件.2 、运用keil软件对程序进行编写，程序见附件。3、打开protues软件.4、运用protues软件对硬件电路进行

4、设计。9c51单片机是该信号发生器的核心，具有 2个定时器，32个并行I/O 口，1个串行 I/O 口，5个中断源。由于本设计功能简单，数据处理容易，数据存储空间也足够，因为 我们采用了片选法选择芯片，进行芯片的选择和地址的译码。在单片机最小最小系统中， 单片机从P1 口接收来自键盘的信号，并通过P0 口输出控制信号，通过DA转换芯片最终 由示波器显示输出波形。单片机引脚分配如下：？XTAL1 XTAL2外接晶振，产生时钟信号。?RST复位电路；?P2 口： 8位数字信号输出输出，外接 DAC0832?P3.6 口和 P3.7 口： DAC0832勺时钟信号；单片机模块单片机输出的是数字信号，

5、因为要得到模拟信号的波形就必须对其进行数模转换。我们采用了 DAC083纵模转换器，该芯片具由8位输入锁存器、8位DACJ存器、8位D/A 转换器及转换控制电路四部分构成。由于其输出为电流输出，因为外加运算放大器LM324 使之转换为电压输出。最后通过示波器显示输出的波形。数模转换模块运放模块整体硬件电路图五、实验结果与分析1、实验现象、数据记录仿真波形2、对实验现象、数据及观察结果的分析与讨论：经过观察调试，冉观察，再调试，最终输出的波形较为理想。此次试验经过一系列 的调试，最终输出的波形为正弦波、方波、三角波。刚开始在给运放接电源时，接的电源不是稳恒直流电源（用示波器测试了一下电源的输出波

6、形，虽然电源上写的是直流稳恒电源，但是发现他的波形掺杂有杂波），所以测出来的波形不是正弦波、方波和三角波。分析原因可能与运放的电源有关，所以在实 验室找到了数控稳恒直流电源，经过给运放供电，发现输出了正弦波、方波、三角波。所以给运放供电的电源必须是经滤波后的平稳电源，否则对运放有很大影响。3、关键点:此次试验关键点是程序的编写，在程序编写的过程中请教了众多的编程高手，最终 在大家的帮助下编写出了能输出正弦波、方波、三角波的程序。此次试验另一个关键点是硬件电路的焊接。 在硬件电路焊接中首先应根据仿真软件 进行焊接，当焊完以后还要对电路进行测试，以防止电路不通。第三个关键点是在给运放供电时的电源一

7、定要是稳恒直流电源，不能掺杂有杂波。六、实验结论基于单片机的信号发生器设计，这个信号发生器的设计中涉及到一个典型的控制过 程。通过单片机控制一个模数转换器 DAC0832产生所需要的电流，然后使用运算放大器 LM324可以将其电流输出线性地转换成电压输出，再将电压经过运算放大器的放大，可以 得到足够幅度的信号。通过程序的控制，可以产生一系列有规律的波形。这样一个信号发 生装置在控制领域有相当广泛的应用范围。最终做出来的信号发生器满足了题目中的所有要求：产生三种波形。正弦波、三角波、矩形波。当然还是存在不足的地方，比如不能实现频率的按一个小的步进调整。并且当频率太 小时矩形波会有些失真。信号发生

8、器可以生成更多的波形，只需要再加些波形表即可。七、指导老师评语及得分：附件：源程序等。正弦波程序：#include #define uchar unsigned char#define uint unsigned intsbit cs=P3A7;sbit wr=P3A6;uchar j;uint ys,a=0;uchar code tosin256=0 x80,0 x83,0 x86,0 x89,0 x8d,0 x90,0 x93,0 x96,0 x99,0 x9c,0 x9f,0 xa2,0 xa5,0 xa8,0 xab,0 xae,0 xb1,0 xb4,0 xb7,0 xba,0 xb

9、c,0 xbf,0 xc2,0 xc5,0 xc7,0 xca,0 xcc,0 xcf,0 xd1,0 xd4,0 xd6,0 xd8,0 xda,0 xdd,0 xdf,0 xe1,0 xe3,0 xe5,0 xe7,0 xe9,0 xea,0 xec,0 xee,0 xef,0 xf1,0 xf2,0 xf4,0 xf5,0 xf6,0 xf7,0 xf8,0 xf9,0 xfa,0 xfb,0 xfc,0 xfd,0 xfd,0 xfe,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xf

10、e,0 xfd,0 xfd,0 xfc,0 xfb,0 xfa,0 xf9,0 xf8,0 xf7,0 xf6,0 xf5,0 xf4,0 xf2,0 xf1,0 xef,0 xee,0 xec,0 xea,0 xe9,0 xe7,0 xe5,0 xe3,0 xe1,0 xde,0 xdd,0 xda,0 xd8,0 xd6,0 xd4,0 xd1,0 xcf,0 xcc,0 xca,0 xc7,0 xc5,0 xc2,0 xbf,0 xbc,0 xba,0 xb7,0 xb4,0 xb1,0 xae,0 xab,0 xa8,0 xa5,0 xa2,0 x9f,0 x9c,0 x99,0 x9

11、6,0 x93,0 x90,0 x8d,0 x89,0 x86,0 x83,0 x80,0 x80,0 x7c,0 x79,0 x76,0 x72,0 x6f,0 x6c,0 x69,0 x66,0 x63,0 x60,0 x5d,0 x5a,0 x57,0 x55,0 x51,0 x4e,0 x4c,0 x48,0 x45,0 x43,0 x40,0 x3d,0 x3a,0 x38,0 x35,0 x33,0 x30,0 x2e,0 x2b,0 x29,0 x27,0 x25,0 x22,0 x20,0 x1e,0 x1c,0 x1a,0 x18,0 x16,0 x15,0 x13,0 x1

12、1,0 x10,0 x0e,0 x0d,0 x0b,0 xOa,0 x09,0 x08,0 x07,0 x06,0 x05,0 x04,0 x03,0 x02,0 x02,0 x01,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x01,0 x02,0 x02,0 x03,0 x04,0 x05,0 x06,0 x07,0 x08,0 x09,0 x0a,0 x0b,0 x0d,0 x0e,0 x10,0 x11,0 x13,0 x15,0 x16,0 x18,0 x1a,0 x1c,0 x1

13、e,0 x20,0 x22,0 x25,0 x27,0 x29,0 x2b,0 x2e,0 x30,0 x33,0 x35,0 x38,0 x3a,0 x3d,0 x40,0 x43,0 x45,0 x48,0 x4c,0 x4e,0 x51,0 x55,0 x57,0 x5a,0 x5d,0 x60,0 x63,0 x66 ,0 x69,0 x6c,0 x6f,0 x72, 0 x76,0 x79,0 x7c,0 x80 ;/* 正弦波码 */void delay(uint z) / 延时子程序uchar i,j;for(i=z;i0;i-)for(j=110;j0;j-);void del

14、ay1(uint y)uint i;for(i=y;i0;i-);void main()cs=1;wr=1;cs=0;wr=0;while(1) / 正弦波P2=tosinj;j+;delay(1);wr=1;cs=1;方波程序：#include #define uchar unsigned char#define uint unsigned intsbit cs=P3A7;sbit wr=P3A6;uchar j;uint ys,a=0;uchar code tosin256=0 x80,0 x83,0 x86,0 x89,0 x8d,0 x90,0 x93,0 x96,0 x99,0 x9

15、c,0 x9f,0 xa2,0 xa5,0 xa8,0 xab,0 xae,0 xb1,0 xb4,0 xb7,0 xba,0 xbc,0 xbf,0 xc2,0 xc5,0 xc7,0 xca,0 xcc,0 xcf,0 xd1,0 xd4,0 xd6,0 xd8,0 xda,0 xdd,0 xdf,0 xe1, 0 xe3,0 xe5,0 xe7,0 xe9,0 xea,0 xec,0 xee,0 xef,0 xf1,0 xf2,0 xf4,0 xf5, 0 xf6,0 xf7,0 xf8,0 xf9,0 xfa,0 xfb,0 xfc,0 xfd,0 xfd,0 xfe,0 xff,0

16、xff, 0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xfe,0 xfd,0 xfd,0 xfc,0 xfb,0 xfa,0 xf9,0 xf8,0 xf7,0 xf6,0 xf5,0 xf4,0 xf2,0 xf1,0 xef,0 xee,0 xec,0 xea,0 xe9,0 xe7,0 xe5,0 xe3,0 xe1,0 xde,0 xdd,0 xda, 0 xd8,0 xd6,0 xd4,0 xd1,0 xcf,0 xcc,0 xca,0 xc7,0 xc5,0 xc2,0 xbf,0 xbc, 0 xba

17、,0 xb7,0 xb4,0 xb1,0 xae,0 xab,0 xa8,0 xa5,0 xa2,0 x9f,0 x9c,0 x99, 0 x96,0 x93,0 x90,0 x8d,0 x89,0 x86,0 x83,0 x80,0 x80,0 x7c,0 x79,0 x76, 0 x72,0 x6f,0 x6c,0 x69,0 x66,0 x63,0 x60,0 x5d,0 x5a,0 x57,0 x55,0 x51, 0 x4e,0 x4c,0 x48,0 x45,0 x43,0 x40,0 x3d,0 x3a,0 x38,0 x35,0 x33,0 x30, 0 x2e,0 x2b,0

18、 x29,0 x27,0 x25,0 x22,0 x20,0 x1e,0 x1c,0 x1a,0 x18,0 x16, 0 x15,0 x13,0 x11,0 x10,0 x0e,0 x0d,0 x0b,0 x0a,0 x09,0 x08,0 x07,0 xO6, 0 x05,0 x04,0 x03,0 x02,0 x02,0 x01,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00, 0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x01,0 x02,0 x02,0 x03,0 x04,0 x05, 0 x06,0 x07,0 x08,0 x

19、09,0 x0a,0 x0b,0 x0d,0 x0e,0 x10,0 x11,0 x13,0 x15, 0 x16,0 x18,0 x1a,0 x1c,0 x1e,0 x20,0 x22,0 x25,0 x27,0 x29,0 x2b,0 x2e, 0 x30,0 x33,0 x35,0 x38,0 x3a,0 x3d,0 x40,0 x43,0 x45,0 x48,0 x4c,0 x4e, 0 x51,0 x55,0 x57,0 x5a,0 x5d,0 x60,0 x63,0 x66 ,0 x69,0 x6c,0 x6f,0 x72, 0 x76,0 x79,0 x7c,0 x80 ;/*正

20、弦波码 */void delay(uint z) /延时子程序uchar i,j;for(i=z;i0;i-) for(j=110;j0;j-);void delay1(uint y)uint i;for(i=y;i0;i-);void main()cs=1;wr=1;cs=0;wr=0;while(1) / 方波P2=0 xff;delay(1);P2=0;delay(1);wr=1;cs=1;三角波程序：#include #define uchar unsigned char#define uint unsigned intsbit cs=P3A7;sbit wr=P3A6;uchar j

21、;uint ys,a=0;uchar code tosin256=0 x80,0 x83,0 x86,0 x89,0 x8d,0 x90,0 x93,0 x96,0 x99,0 x9c,0 x9f,0 xa2,0 xa5,0 xa8,0 xab,0 xae,0 xb1,0 xb4,0 xb7,0 xba,0 xbc,0 xbf,0 xc2,0 xc5,0 xc7,0 xca,0 xcc,0 xcf,0 xd1,0 xd4,0 xd6,0 xd8,0 xda,0 xdd,0 xdf,0 xe1,0 xe3,0 xe5,0 xe7,0 xe9,0 xea,0 xec,0 xee,0 xef,0 x

22、f1,0 xf2,0 xf4,0 xf5,0 xf6,0 xf7,0 xf8,0 xf9,0 xfa,0 xfb,0 xfc,0 xfd,0 xfd,0 xfe,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xff,0 xfe,0 xfd,0 xfd,0 xfc,0 xfb,0 xfa,0 xf9,0 xf8,0 xf7,0 xf6,0 xf5,0 xf4,0 xf2,0 xf1,0 xef,0 xee,0 xec,0 xea,0 xe9,0 xe7,0 xe5,0 xe3,0 xe1,0 xde,0 x

23、dd,0 xda,0 xd8,0 xd6,0 xd4,0 xd1,0 xcf,0 xcc,0 xca,0 xc7,0 xc5,0 xc2,0 xbf,0 xbc,0 xba,0 xb7,0 xb4,0 xb1,0 xae,0 xab,0 xa8,0 xa5,0 xa2,0 x9f,0 x9c,0 x99,0 x96,0 x93,0 x90,0 x8d,0 x89,0 x86,0 x83,0 x80,0 x80,0 x7c,0 x79,0 x76,0 x72,0 x6f,0 x6c,0 x69,0 x66,0 x63,0 x60,0 x5d,0 x5a,0 x57,0 x55,0 x51,0 x4e,0 x4c,0 x48,0 x45,0 x43,0 x40,0 x3d,0 x3a,0 x38,0 x35,0 x33,0 x30,0 x2e,0 x2b,0 x29,0 x27,0 x25,0 x22,0 x20,0 x1e,0 x1c,0 x1a,