求大神帮助ADC0809输出一直为0

#include<reg52.h>
sbit ST=P2^0;
sbit OE=P2^2;
sbit EOC=P2^1;
sbit CLK=P2^3;
sbit led=P1^1;
unsigned char getdata;
void TimeInitial()
{
TMOD=0x10;
TH1=(65536-200)/256;
TL1=(65536-200)%256;
EA=1;
ET1=1;
TR1=1;
}
void main()
{
TimeInitial();
led = 1;
while(1)
{
ST=0;
OE=0;
ST=1;
ST=0;
while(EOC==0);
OE=1;
getdata=P0;
light=getdata*0.196;
OE=0;
if(light>35)
led = 0;
}
}
void t1(void) interrupt 3
{
TH1=(65536-200)/256;
TL1=(65536-200)%256;
CLK=~CLK;
}