产生波形实验（DA转换）

/*DA转换实验 例如产生锯齿波*/


#include


unsigned char xdata ad_cs0   _at_  0xc000;
unsigned char xdata ad_cs1   _at_  0xc001 ;
unsigned char xdata key_seg   _at_  0xd004;
unsigned char xdata key_bit   _at_  0xd002;


sbit EOC=P3^2;
unsigned char disp_ram[6];
unsigned char seg7[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,
                      0x77,0x7c,0x39,0x5e,0x79,0x71,0,0x80};
unsigned char scan[]={0x01,0x02,0x04,0x08,0x10,0x20};


void delay()
{
  unsigned char i,j;
  for (i=0;i<200;i++)
    for (j=0;j<2;j++);
}


void main()
{
   unsigned char i=0;
   unsigned char ad_value;
   unsigned char tmp,a;






    disp_ram[0]=17;
    disp_ram[1]=16;
    disp_ram[2]=16;
    disp_ram[3]=16;
    disp_ram[4]=16;
    disp_ram[5]=16;


    ad_cs0=0;


    while(1)
    {
       key_bit=scan[i];
       a=seg7[disp_ram[i]];
       if (i==5)
          a=a|0x80;
       key_seg=a;
       delay();
       i++;
       i=i%6  ;


       if (EOC)
       {
          ad_value=ad_cs0;
          disp_ram[5]=ad_value*5/256;
          tmp=(ad_value*5)%256;
          disp_ram[4]=tmp/100;
          disp_ram[3]=(tmp%100)/10;
       }
       ad_cs0=0;
    } ;




}

DA转换 Code

本文转自蓬莱仙羽51CTO博客，原文链接：http://blog.51cto.com/dingxiaowei/1366578，如需转载请自行联系原作者