1.实现功能（设计概述）：

1.2个通道同时输出正弦波、三角波、方波或锯齿波。
2.使用点阵屏显示波形，通过按钮切换各通道波形。
3.输出波形频率固定为7.5HZ。

2.仿真全图

3.元器件清单

型号	型号*数量
单片机	AT89C51*1
电容	10uf*1
电容	30pf*2
晶振	12MHZ*1
电阻	10K
按钮	*4
数模芯片	DAC0832*2
集成运放	LM358
串转并芯片	74LS595*2
点阵	884
非门芯片	74LS595*2
译码器	74C154

4.软件流程图

5.仿真运行图

6.相关代码

#include<reg51.h>
#include"absacc.h"
#include"intrins.h"
#define uchar unsigned char
#define uint unsigned int
#define out1 XBYTE[0xfeff]
#define out2 XBYTE[0xfdff]
#define uchar unsigned char
#define uint unsigned int

sbit SRCLK=P3^3;//595引脚
sbit RCLK=P3^4;
sbit SER=P3^5;
sbit k1=P3^0;//按钮
sbit k2=P3^1;
sbit k3=P3^2;

uchar boxing1=0,boxing2=0;//波形。正弦、三角、方波
uchar time=0;//计时
uchar code zhengx[]={//正弦编码
128,131,134,137,141,144,147,150,153,156,159,162,165,168,171,174,177,180,183,186,188,191,194,
196,199,202,204,207,209,212,214,216,219,221,223,225,227,229,231,233,234,236,238,239,241,242,244,245,246,247,249,
250,250,251,252,253,254,254,255,255,255,255,255,255,255,255,255,255,255,255,255,254,254,253,252,251,250,250,249,247,
246,245,244,242,241,239,238,236,234,233,231,229,227,225,223,221,219,216,214,212,209,207,204,202,199,196,194,191,
188,186,183,180,177,174,171,168,165,162,159,156,153,150,147,144,141,137,134,131,128,125,122,119,115,112,109,106,
103,100,97,94,91,88,85,82,79,76,73,70,68,65,62,60,57,54,52,49,47,44,42,40,37,35,33,31,29,27,25,23,22,20,18,17,15,
14,12,11,10,9,7,6,6,5,4,3,2,2,1,1,1,1,0,0,0,0,0,0,1,1,1,2,2,3,4,5,6,6,7,9,10,11,12,14,15,17,18,20,22,23,25,27,29,
31,33,35,37,40,42,44,47,49,52,54,57,60,62,65,68,70,73,76,79,82,85,88,91,94,97,100,103,106,109,112,115,119,122,
125,128,128,128};

uchar tongdao=0;//通道
uchar str1[8]={//正弦
0x30,0x08,0x0C,0x0C,0x18,0x30,0x30,0x18
};
uchar str2[8]={//三角波
0x20,0x10,0x08,0x04,0x04,0x08,0x10,0x20
};
uchar str3[8]={//方波
0x3C,0x04,0x04,0x3C,0x20,0x20,0x3C,0x00
};
uchar str4[8]={//Hz
0x7E,0x08,0x08,0x7E,0x48,0x68,0x58,0x48
};
uchar str5[8]={//7.5
0x62,0x12,0x0E,0x40,0x0E,0x4A,0x7A,0x00
};
uchar str6[]={0x3C,0x08,0x10,0x3C,0x08,0x10,0x20,0x00};//锯齿波
void delay(uint xms)//延时函数
{
	while(xms--);
}

//595发送函数
void Hc595SendByte(uchar i)
{
	uchar a,dat1;
	dat1=i;
	SRCLK = 1;
	RCLK = 1;

	for(a=0;a<8;a++)		//发送8位数
	{
		if(dat1 & 0x80)
			SER =1;	//从最高位开始发送
		else
			SER=0;
		dat1 <<= 1;

		SRCLK = 0;			//发送时序
		_nop_();
		_nop_();
		SRCLK = 1;	
	}
	/*RCLK = 0;
	_nop_();
	_nop_();
	RCLK = 1;*/
}
void lock()//锁定
{
	RCLK = 0;
	_nop_();
	_nop_();
	RCLK = 1;
}
void display()//显示
{
	uchar i;
	for(i=0;i<8;i++)//通道1
	{		
		Hc595SendByte(0xff);
		Hc595SendByte(0xff);
		lock();
		P1=i;
		Hc595SendByte(~str5[i]);//频率		
		switch(boxing1)
		{
			case 0:	Hc595SendByte(~str1[i]);break;//正弦
			case 1:	Hc595SendByte(~str2[i]);break;//三角波
			case 2:	Hc595SendByte(~str3[i]);break;//方波
			case 3:	Hc595SendByte(~str6[i]);//锯齿波
		}
		lock();
		delay(100);
	}
	
}
void main()
{	
//设置定时器
	TMOD|=0X01;
	TH0=0xfc;//给定时器赋初值
	TL0=0x18;	
	ET0=1;//打开定时器0中断允许
	TR0=1;//打开定时器
	EA=1;//打开总中断
	while(1)
	{
		display();
		if(!k1)//通道1
		 	tongdao=0;
			while(!k3);
		}
	}
}
void Timer0() interrupt 1//定时器中断
{
	//通道1输出
	if(boxing1==0)//正弦波
	{		
		out1=zhengx[time];
		time++;
	}
	if(boxing1==1)//三角波
	{
		if(time<128)
		{
			out1=time;
		}
		else
		{
			out1=255-time;
		}
		time++;
	}
	if(boxing1==2)//方波
	{
		if(time<128)
			out1=0;		
		else
		{
			out1=0xff;
		}
		time++;
	}
	if(boxing1==3)//锯齿波
	{
		out1=time;
		time++;
	}
	//通道2输出
	if(boxing2==0)//正弦波
	{		
		out2=zhengx[time];
		time++;
	}
	if(boxing2==1)//三角波
	{
		if(time<128)
		{
			out2=time;
		}
		else
		{
			out2=255-time;
		}
		time++;
	}
	if(boxing2==2)//方波
	{
		if(time<128)
			out2=0;		
		else
		{
			out2=0xff;
		}
		time++;
	}
	if(boxing2==3)//锯齿波
	{
		out2=time;
		time++;
	}
	TH0=0xfc;//给定时器赋初值
	TL0=0x18;
}