#include <intrins.h>

#define ch0 0   //AD通道號
#define ch1 1
#define ch2 2
#define ch3 3
#define ch4 4
#define ch5 5
#define ch6 6
#define ch7 7

unsigned int Res;

//TLC1543 A/D用轉換用
sbit CLOCK  =P2^4;
sbit D_IN   =P2^7;
sbit D_OUT  =P2^5;
sbit _CS    =P2^6;

void DelayMS(unsigned int i)
{
  unsigned int j,k;
    for(k=0;k<i;k++)
        for(j=0;j<60;j++);
}

unsigned int read1543(unsigned char port) //從TLC1543讀取采樣值,形參port是采樣的通道號
{
unsigned int data ad;
unsigned char data  i,al=0,ah=0;
    CLOCK=0;
    _CS=0;
    port<<=4;
for (i=0;i<4;i++) //把通道號打入1543
{
    D_IN=(bit)(port&0x80);CLOCK=1;CLOCK=0;
    port<<=1;
}

for (i=0;i<6;i++) //填充6個CLOCK
{
    CLOCK=1;CLOCK=0;
}

_CS=1;

_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();
_nop_();_nop_();_nop_();

_CS=0; //等待AD轉換

for (i=0;i<2;i++) //取D9,D8
{
    D_OUT=1;
    CLOCK=1;
    ah<<=1;
    if (D_OUT) ah|=0x01;
    CLOCK=0;
} 

for (i=0;i<8;i++) //取D7--D0
{
    D_OUT=1;
    CLOCK=1;
    al<<=1;
if (D_OUT) al|=0x01;
    CLOCK=0;
} 

_CS=1;


ad=(unsigned int)ah;ad<<=8;ad|=al; //得到AD值

return (ad);
}

unsigned int ReadADC(unsigned char channel)
{

unsigned int ADValue[5],temp;

 char n,i,j,min;


     for (n=0;n<5;n++)              //15次采樣
        {
            ADValue[n]=read1543(channel)&0x03FF;
        }

     n=5;                           //排序
     for (i=0;i<n-1;i++)            
        {   min=i;
            for (j=i+1;j<n;j++)

                if(ADValue[min]>ADValue[j])min=j;

            temp=ADValue[i];

            ADValue[i]=ADValue[min];

            ADValue[min]=temp;      				
        }
                                   //對中間5個值求和

return ADValue[2];

}