DAC0832什么原因导致失真那么大

ID:296231 · 发表于 2018-4-7 16:11

程序如下：
电路如图；
问题就是为什么会失真那么大，除了方波之外，正弦，三角都有问题，请大家帮忙看看

单片机源程序如下:

#include<reg51.h>
#include <absacc.h>
#define uint unsigned int
#define uchar unsigned char
void daly3();
void daly2();
void daly1();
void delay39us();
void delay10ms();
int k;
uchar code sin[]={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,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,0xFD,0xFD,0xFC,0xFB,0xFA,0xF9,0xF8,0xF7,0xF6,
0xF5,0xF4,0xF2,0xF1,0xEF,0xEE,0xEC,0xEA,0xE9,0xE7,0xE5,0xE3,0xE1,0xDF,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,
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,
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,0x7E};
void delay(uchar t)
{
while(t--);
}
void zheng()
{
uint i;
for(i=0;i<=255;i++)
{
P1=sin[i];
delay39us();
}
}
void fang()
{
P1=0;
delay15ms();
P1=0xff;
delay15ms();
}
void sanjiao()
{ uint i;
for(i=0;i<255;i++)
{
P1=i;
daly2();
}
for(i=255;i>0;i--)
{
P1=i;
daly2();
}
}
void key()
{
P0=0xf0;
if(P0==0xe0)
{delay(100);
if(P0==0xe0)
k=1;
}
else if(P0==0xd0)
{delay(100);
if(P0==0xd0)
k=2;
}
else if(P0==0xb0)
{delay(100);
if(P0==0xb0)
k=3;
}
else k=0;
}
void main()
{
while(1)
{
key();
if(k==1)
while(1)
{
zheng();
key();
if(k!=0)
break;
}
else if(k==2)
while(1)
{
fang();
key();
if(k!=0)
break;
}
else if(k==3)
while(1)
{
sanjiao();
key();
if(k!=0)
break;
}
}
}
void daly1()
{
{
unsigned char a,b,c;
for(a=0;a<5;a++)
for(b=0;b<10;b++)
for(c=0;c<220;c++);
}
}
void daly2()
{
unsigned char a;
for(a=10;a>0;a--);
}
void daly3()
{
unsigned char a;
for(a=200;a>0;a--);
}
void delay39us(void)
{
unsigned char a;
for(a=9;a>0;a--);
}
void delay10ms(void)
{
unsigned char a,b,c;
for(c=5;c>0;c--)
for(b=4;b>0;b--)
for(a=248;a>0;a--);
}