AT89C51+DA實(shí)現(xiàn)的波形發(fā)生器

ID:128229 · 發(fā)表于 2016-6-29 20:50

本程序?qū)崿F(xiàn)的是通過4*4鍵盤的三個(gè)鍵值（0x7d,0xbd,0xdd;分別對應(yīng)鍵盤的數(shù)字1，2，3）來選擇輸出波形（正弦，鋸齒，方波）。幾百年沒寫c程序了，出的波形都不是特別好看，如果各位看官覺得那里有錯(cuò)的請指點(diǎn)，謝謝！
[color=#00CC33,strength=3);text-shadow:1px]電路連接：P0口接DA，P1控制鍵盤，中斷用外部中斷1（INT1），J14為輸出端用示波器觀察波形。
程序：
# include < absacc.h >
# include < reg51.h >
#include<math.h>
# define DAC0832  XBYTE [0xc000 ]
# define uchar unsigned char
# define uint unsigned int
void sinusoidal();
void triangle();
void square();
void dlms() ;
unsigned char read_key(unsigned char);

code unsigned char Sin[128]={64,67,70,73,76,79,82,85,88,91,94,96,99,102,104,106,
                                       109,111,113,115,117,118,120,121,123,124,125,126,126,
                                       127,127,127,127,127,127,127,126,126,125,124,123,121,
                                       120,118,117,115,113,111,109,106,104,102,99,96,94,91,
                                       88,85,82,79,76,73,70,67,64,60,57,54,51,48,45,42,39,
                                       36,33,31,28,25,23,21,18,16,14,12,10,9,7,6,4,3,2,1,
                                       1,0,0,0,0,0,0,0,1,1,2,3,4,6,7,9,10,12,14,16,18,21,23,
                                       25,28,31,33,36,39,42,45,48,51,54,57,60};

code unsigned char scan[4]={0xef,0xdf,0xbf,0x7f};

unsigned char  key, old_key ; //鍵碼,掃描碼
uchar counter;

void dlms() //延時(shí)
{
uchar k;
for(k=200;k>0;k--){}
}

void main(){
  IT1=0;
  EX1=1;
  PX1=1;
  EA=1;
  P1=0x0f;

while(1){

      switch(key)
         {
            case 0x1: sinusoidal();  //zhenxian
                     break;
            case 0x2:  triangle();    //jvchi
                     break;
            case 0x3: square(); //fanbo
                     break;
            default:break;
      }

}
}

void get_keypad_code() interrupt 2
{
unsigned char i;
uchar scan;
  for (i=1;i<=4;i++)
   {
      P1=scan;
      old_key=P1|0xf0;
   if(old_key!=0xff)          //有鍵？
{
            key=read_key(scan);    //讀鍵碼
         dlms();                //延時(shí)5-10ms,去抖動(dòng)
         }
      }
}

uchar read_key(uchar scan)
{
P1=scan;    //掃描
switch(P1)    //返回掃描碼->鍵碼
{
   case 0x77:return(0x7);
   case 0xb7:return(0x8);
   case 0xd7:return(0x9);
   case 0xe7:return(0xd);
   case 0x7b:return(0x4);
   case 0xbb:return(0x5);
   case 0xdb:return(0x6);
   case 0xeb:return(0xc);
   case 0x7d:return(0x1);
   case 0xbd:return(0x2);
   case 0xdd:return(0x3);
   case 0xed:return(0xb);
   case 0x7e:return(0xf);
   case 0xbe:return(0x0);
   case 0xde:return(0xe);
   case 0xee:return(0xa);
   default:  return(0xff);

   }
}

void sinusoidal()
{
                  for(counter=0;counter<128;counter++){
                  DAC0832=Sin[counter];
         }
}

void triangle ()
{
for(counter=0;counter<128;counter++ ){
      DAC0832=counter;
         dlms();
}
}

void square()
{
   for(counter=1;counter<128;counter++)
   {
   if(counter<=64) DAC0832=0x00;
   else DAC0832=0xf0;
   }
}

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