PIC16F877A单片机-AD转换经典C程序

      #include  
      #define   HC595_SER    RB7
      #define   HC595_SCK     RB6
      #define   HC595_RCK     RB5
      #define   key_164_data   RB3
      #define   key_164_clk    RB2
      #define   key_com1       RB1
      #define   key_com0       RB0
      #define   TURE   1

      bit   key_finish;        //定义位变量，这是PICmate仿真软件环境的特有的地方   unsigned int   sample_key;
      unsigned int   sample_keyBuf[2];
      unsigned int   key_value;
      unsigned char key_row_sel;
      unsigned char key_number;//键号
      unsigned int   T100ms;
      unsigned char disbuf[8];
      unsigned int ad_data;
      int a[4];
      const unsigned char seven_seg[16]=
{0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
      //----------------------------------------------
      void disbuf_update(void)
     {
          disbuf[7]=seven_seg[a[3]];
          disbuf[6]=seven_seg[a[2]];
          disbuf[5]=seven_seg[a[1]];
          disbuf[4]=seven_seg[a[0]];
          disbuf[3]=seven_seg[0];
          disbuf[2]=seven_seg[0];
          disbuf[1]=seven_seg[0];
          disbuf[0]=seven_seg[0];
      }
      //----------------------------------------------
     //发送一个字节
      void s_pData(unsigned char key)         //形参key对应着实参disbuf[i]
     {
          unsigned char i;
             for(i=0;i<8;i++)
         {
           if(0x80&(key<                 HC595_SER=1;
           else HC595_SER=0;
             HC595_SCK=0;
             HC595_SCK=1;
        }
      }
      //----------------------------------------------

//----------------------------------------------
     void display (void)
    {
        unsigned char i;
        for(i=0;i<8;i++)
            s_pData(disbuf[i]);
        HC595_RCK=0;
        HC595_RCK=1;
    }
    //----------------------------------------------

void start_ad_change (void) //开始A/D转化
{
     ADCON1=0x80;
     ADCON0=0x48;
     ADON=1;
     ADIF=0;
     asm("nop");
     asm("nop");
     asm("nop");
     asm("nop");
     asm("nop");
     asm("nop");
     asm("nop");
     asm("nop");
     ADGO=1;
     while(ADIF==0);
     ADIF=0;
     ad_data =ADRESL;
     ad_data |=(unsigned int)(ADRESH<<8);     //强制ADRESH的8位放在ad_data的高八位
     ADON=0;
}

void two_change_ten(void)        //二进制转十进制
{
int s=0,i;
for(i=0;i<=15;i++)
     {if(0x0001&(ad_data>>i))
            s=s+pow(2,i);
     }
a[0]=s%10;
a[1]=(s/10)%10;
a[2]=(s/100)%10;
a[3]=s/1000;
}

     //主程序
int main(void)
{
         PORTB=0;
         TRISB=0x03;
         PORTA=0;
         TRISA=0x02;
         while(1)
     {
         start_ad_change();
         two_change_ten();
         disbuf_update();
display();
     }

}
     //----------------------------------------------