仿真电路图：
部分参考代码：
#include<reg52.h>
#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 No.1 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,
0xf8,0xf0,0xe8,0xe0,0xd8,0xd0,0xc8,0xc0,0xb8,0xb0,0xa8,0xa0,0x98,0x90,0x88,0x80,
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,0xe1,0xe3,0xe5,0xe7,0xe9,0xea,0xec,
0xee,0xef,0xf1,0xf2,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfd,0xfe,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 ,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,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 P1
sbit 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; // 性更高,使加数有个上限，不会一直加下去*/
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;
}
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链接：https://pan.baidu.com/s/1jUHhVUiVOdTTCy2MHmFcCg
提取码：1234
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