用 單片機 產生方波、鋸齒波、三角波、梯形波，頻率可調

 

#include

#define uchar unsigned char

#define uint unsigned int

unsigned char x=0,m=0,y=128;

sbit WR_DA=P2^1;

sbit CS_DA=P2^0;//DA與 單片機 的接口

sbit S0=P3^0; //波形選擇，每次按下將產生不同的波形

sbit S1=P3^1; //頻率減

sbit S2=P3^2; //頻率加

sbit S3=P3^3; //調節(jié)方波的占空比

uchar code SinTab[256]={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,0xe9,0xe7,0xe5,0xe3,0xe1,0xde,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,0x89,0x86,0x83,0x80,0x80,0x7c,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,0x80 };

void delayms(uint t)

{

uint i;

while(t--)

{

for (i=0;i<125;i++);//對于11.0592M時鐘，約延時1ms

}

}

void delay(uint t)

{

uint i;

for (i=t;i>0;i--);

}

void time0_init()

{

TMOD|=0x01; //定時器設置 16位

TH0=-50000/256;

TL0=-50000%256;//初始化值

ET0=1;

TR0=1;

EA=1;

}

void time0_int(void) interrupt 1

{

TR0=0;//關閉定時器

TH0=-50000/256;

TL0=-50000%256;//重裝初值

if(S0==0)

{

delayms(10);//按鍵消抖

if(S0==0) m++;

while(!S0);//松手檢測

}

if(S1==0)

{

delayms(10);

if(S1==0) x=x+1;

while(!S1);//松手檢測

}

if(S2==0)

{

delayms(10);

if(S2==0) x=x-1;

while(!S2);//松手檢測

}

if(S3==0)

{

delayms(10);

if(S3==0) y=y+5;

while(!S3);//松手檢測

}

if(y>254) y=0;

if(m>5) m=0;

if(x>50) x=0;

TR0=1;//啟動定時器

}

void fangbo() //方波

{

uchar i,j;

j=255-y;

CS_DA=0;

WR_DA=0;

for(i=y;i>0;i--)

{

P0=0;

delay(x);

}

while(j--)

{

P0=255;

delay(x);

}

}

void juchi() //鋸齒波

{

uchar i;

CS_DA=0;

WR_DA=0;

for(i=255;i>0;i--)

{

P0=i;

delay(x);

}

}

void sanjiao() //三角波

{

uchar i;

CS_DA=0;

WR_DA=0;

for(i=0;i<255;i++)

{

P0=i;

delay(x);

}

while(i--)

{

P0=i;

delay(x);

}

}

void tixing() //梯形波

{

uchar i=255,j,k;

CS_DA=0;

WR_DA=0;

while(i--)

{

P0=i;

delay(x);

}

for(j=0;j<100;j++)

{

P0=0;

delay(x);

}

for(k=0;k<255;k++)

{

P0=k;

delay(x);

}

}

void sin() //正弦波

{

uchar a;

CS_DA=0;

WR_DA=0;

for(a=0;a<255;a++)

{

P0=SinTab[a];

delay(x);

}

}

main()

{

time0_init();

while(1)

{

switch(m)

{

case 0:

fangbo(); //方波

break;

case 1:

juchi(); //鋸齒波

break;

case 2:

sanjiao(); //三角波

break;

case 3:

sin(); //正弦波

break;

case 4:

tixing(); //梯形波

break;

default: fangbo();

}

}

}