用單片機產生方波、鋸齒波、三角波、梯形波，頻率可調

#include
#defineucharunsignedchar
#defineuintunsignedint
unsignedcharx=0,m=0,y=128;
sbitWR_DA=P2^1;
sbitCS_DA=P2^0;//DA與 單片機 的接口
sbitS0=P3^0;//波形選擇，每次按下將產生不同的波形
sbitS1=P3^1;//頻率減
sbitS2=P3^2;//頻率加
sbitS3=P3^3;//調節(jié)方波的占空比
ucharcodeSinTab[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};
voiddelayms(uintt)
{
uinti;
while(t--)
{
for(i=0;i<125;i++);//對于11.0592M時鐘，約延時1ms
}
}
voiddelay(uintt)
{
uinti;
for(i=t;i>0;i--);
}

voidtime0_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;
}
voidtime0_int(void)interrupt1
{
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
}
voidfangbo()//方波
{
uchari,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);
}
}
voidjuchi()//鋸齒波
{
uchari;
CS_DA=0;
WR_DA=0;
for(i=255;i>0;i--)
{
P0=i;
delay(x);
}
}
voidsanjiao()//三角波
{
uchari;
CS_DA=0;
WR_DA=0;
for(i=0;i<255;i++)
{
P0=i;
delay(x);
}
while(i--)
{
P0=i;
delay(x);
}
}
voidtixing()//梯形波
{
uchari=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);
}
}
voidsin()//正弦波
{
uchara;
CS_DA=0;
WR_DA=0;
for(a=0;a<255;a++)
{
P0=SinTab[a];
delay(x);
}
}
main()
{
time0_init();
while(1)
{
switch(m)
{
case0:
fangbo();//方波
break;
case1:
juchi();//鋸齒波
break;
case2:
sanjiao();//三角波
break;
case3:
sin();//正弦波
break;
case4:
tixing();//梯形波
break;
default:fangbo();
}
}
}