显示频率，幅度可调，可产生四种波形，正弦波，方波，锯齿波，三角波，希望你能喜欢，给你发了一张效果图，喜欢的话别忘了采纳我的回答啊#include<>#define uchar unsigned char#define uint unsigned int#define DAdata P0 //DA数据端口sbit DA_S1= P2^0; // 控制DAC0832的8位输入寄存器，仅当都为0时，可以输出数据(处于直通状态)，否则，输出将被锁存sbit DA_S2= P2^1; // 控制DAC0832的8位DAC寄存器，仅当都为0时，可以输出数据(处于直通状态)，否则，输出将被锁存sbit key= P3^2;uchar wavecount; //'抽点'计数uchar THtemp,TLtemp;//传递频率的中间变量uchar judge=1; //在方波输出函数中用于简单判别作用uchar waveform; //当其为0、1、2时，分别代表三种波uchar code freq_unit[3]={10,50,200}; //三种波的频率单位uchar idata wavefreq[3]={1,1,1}; //给每种波定义一个数组单元，用于存放单位频率的个数uchar code lcd_hang1[]={"Sine Wave " "Triangle Wave " "Square Wave " "Select Wave: " "press key! "};uchar idata lcd_hang2[16]={"f= Hz "};uchar code waveTH[]={0xfd,0xfe,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xfd,0xfe,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xec,0xf6,0xf9,0xfb,0xfc,0xfc,0xfd,0xfd,0xfd,0xfe};uchar code waveTL[]={0x06,0x8a,0x10,0x4e,0x78,0x93,0xa8,0xb3,0xbe,0xc6, //正弦波频率调整中间值0xac,0xde,0x48,0x7a,0x99,0xaf,0xbb,0xc8,0xd0,0xde, //三角波频率调整中间值0x88,0x50,0x90,0x32,0x34,0xbe,0x4a,0xa3,0xe5,0x2c};/******************************************************************** *****************************/uchar code triangle_tab[]={ //每隔数字8，采取一次0x00,0x08,0x10,0x18,0x20,0x28,0x30,0x38,0x40,0x48,0x50,0x58,0x60,0x68 ,0x70,0x78,0x80,0x88,0x90,0x98,0xa0,0xa8,0xb0,0xb8,0xc0,0xc8,0xd0,0xd8,0xe0,0xe8, 0xf0,0xf8,0xff,0xf8,0xf0,0xe8,0xe0,0xd8,0xd0,0xc8,0xc0,0xb8,0xb0,0xa8,0xa0,0x98,0x90,0 x88,0x80,0x78,0x70,0x68,0x60,0x58,0x50,0x48,0x40,0x38,0x30,0x28,0x20,0x18,0x10 ,0x08,0x00};uchar code sine_tab[256]={//输出电压从0到最大值（正弦波1/4部分）0x80,0x83,0x86,0x89,0x8d,0x90,0x93,0x96,0x99,0x9c,0x9f,0xa2,0xa5,0xa8, 0xab,0xae,0xb1,0xb4,0xb7,0xba,0xbc,0xbf,0xc2,0xc5,0xc7,0xca,0xcc,0xcf,0xd1,0xd4,0xd6,0xd8,0xda,0xdd,0xdf,0x e1,0xe3,0xe5,0xe7,0xe9,0xea,0xec,0xee,0xef,0xf1,0xf2,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfd,0 xfe,0xff,0xff,0xff,0xff,0xff,0xff,//输出电压从最大值到0（正弦波1/4部分）0xff,0xff,0xff,0xff,0xff,0xff,0xfe,0xfd,0xfd,0xfc,0xfb,0xfa,0xf9,0xf8,0xf7,0xf6, 0xf5,0xf4,0xf2,0xf1,0xef,0xee,0xec,0xea,0xe9,0xe7,0xe5,0xe3,0xe1,0xde,0xdd,0xda,0xd8,0xd6,0xd4, 0xd1,0xcf,0xcc,0xca,0xc7,0xc5,0xc2,0xbf,0xbc,0xba,0xb7,0xb4,0xb1,0xae,0xab,0xa8,0xa5,0xa2,0x9f,0x9c,0x99 , 0x96,0x93,0x90,0x8d,0x89,0x86,0x83,0x80,//输出电压从0到最小值（正弦波1/4部分）0x80,0x7c,0x79,0x76,0x72,0x6f,0x6c,0x69,0x66,0x63,0x60,0x5d,0x5a,0x57, 0x55,0x51,0x4e,0x4c,0x48,0x45,0x43,0x40,0x3d,0x3a,0x38,0x35,0x33,0x30,0x2e,0x2b,0x29,0x27,0x25,0x22,0x20 ,0x1e,0x1c,0x1a,0x18,0x16 ,0x15,0x13,0x11,0x10,0x0e,0x0d,0x0b,0x0a,0x09,0x08,0x07,0x06,0x05,0x04,0x03,0x02 ,0x02,0x01,0x00,0x00,0x00,0x00,0x00,0x00,//输出电压从最小值到0（正弦波1/4部分）0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x02 ,0x02,0x03,0x04,0x05,0x06,0x0 7,0x08,0x09,0x0a,0x0b,0x0d,0x0e,0x10,0x11,0x13,0x15 ,0x16,0x18,0x1a,0x1c,0x1e,0x20,0x22,0x25,0x27,0x29,0x2b ,0x2e,0x30,0x33,0x35,0x38,0x3a,0x3d,0x40,0x43,0x45,0x48,0x4c,0x4e,0x51,0x55,0x57,0x5a,0x5d,0x60,0x63,0x66 ,0x69,0x6c,0x6f,0x72,0x76,0x79,0x7c,0x80};void delay(uchar z){uint x,y;for(x=z;x>0;x--)for(y=110;y>0;y--);}void triangle_out() //三角波输出{DAdata=triangle_tab[wavecount++];if(wavecount>64) wavecount=0;DA_S1=0; //打开8位输入寄存器DA_S1=1; //关闭8位输入寄存器void sine_out() //正弦波输出{DAdata=sine_tab[wavecount++];DA_S1=0; //打开8位输入寄存器DA_S1=1; //关闭8位输入寄存器}void square_out() //方波输出{judge=~judge;if(judge==1) DAdata=0xff;else DAdata=0x00;DA_S1=0; //打开8位输入寄存器DA_S1=1; //关闭8位输入寄存器}/************1602液晶的相关函数*************/#define lcd_ports P1sbit rs=P2^2;sbit rw=P2^3;sbit lcden=P2^4;void write_com(uchar com){rs=0; //置零，表示写指令lcden=0;lcd_ports=com;delay(5);lcden=1;delay(5);lcden=0;}void write_date(uchar date){rs=1; //置1，表示写数据（在指令所指的地方写数据）lcden=0;lcd_ports=date;delay(5);lcden=1;delay(5);lcden=0;void disp_lcd(uchar addr,uchar *temp1){uchar num;write_com(addr);delay(1); //延时一会儿for(num=0;num<16;num++){write_date(temp1[num]);//或者这样写write_date(*(temp1+num));delay(1);}}void init_lcd(){//uchar num;lcden=0; //可有可无rw=0; //初始化一定要设置为零，表示写数据write_com(0x38); //使液晶显示点阵，为下面做准备write_com(0x0c); //初始设置write_com(0x06); //初始设置write_com(0x01); //清零write_com(0x80); //使指针指向第一行第一格disp_lcd(0x80,&lcd_hang1[3*16]); //在第一行显示disp_lcd(0xc0,&lcd_hang1[4*16]); //在第二行显示}/********************1602液晶函数声明结束*********************/ void main(){uchar i=0;DA_S2=0; //使DAC寄存器处于直通状态DAdata=0;DA_S1=1; //关闭8位输入寄存器init_lcd();waveform=0;TMOD=0x01; //设置定时器0为16位工作方式IT0=1; //设置外部中断0为下降沿触发ET0=1; //开定时器中断EX0=1;EA=1;while(1){//DAout(0xff); //可输出TTL波形//DAout(0x80);//T_temp=32;}}void timer0() interrupt 1{TH0=THtemp;TL0=TLtemp;if(waveform==0) sine_out();else if(waveform==1) triangle_out();else if(waveform==2) square_out();}void key_int0() interrupt 0{uchar keytemp;uint total_freq; //总频率EA=0; TR0=0; //关总中断与定时器delay(5); //延时够吗if(key==0) //确实有按键按下而引发中断{keytemp=P3&0xf0; //获取P3口高四位的值switch(keytemp){case 0xe0: //选择波形waveform++;if(waveform>2) waveform=0;break;case 0xd0: //频率按规定单位依次增加wavefreq[waveform]++;if(wavefreq[waveform]>10) wavefreq[waveform]=1; // /*这边要用“>10”，因为它比“=11”可靠break;case 0xb0: //频率按规定单位依次衰减wavefreq[waveform]--;if(wavefreq[waveform]<1) wavefreq[waveform]=10; //这边要用“<1”，因为它比“=0”可靠性更高break;case 0x70: //TTL输出DA_S2=1; //使DAC寄存器关闭break;}THtemp=waveTH[waveform*10+(wavefreq[waveform]-1)]; //方括号中选取第几个数后，并把该值赋给T_tempTLtemp=waveTL[waveform*10+(wavefreq[waveform]-1)];total_freq= wavefreq[waveform] * freq_unit[waveform]; //求输出频率（个数*单位）lcd_hang2[5]=total_freq%10+0x30; //在液晶中显示个位，(0x30 在液晶显示中表示数字0)total_freq/=10; lcd_hang2[4]=total_freq%10+0x30; //在液晶中显示时十位total_freq/=10; lcd_hang2[3]=total_freq%10+0x30; //在液晶中显示时百位total_freq/=10; lcd_hang2[2]=total_freq%10+0x30; //在液晶中显示时千位disp_lcd(0x80,&lcd_hang1[waveform*16]); //在第一行显示disp_lcd(0xc0,lcd_hang2); //在第二行显示}wavecount=0; //'抽点'计数清零while(!key);EA=1; TR0=1; //开启总中断与定时器}。