#include<reg52.h>
unsigned int n=0;
unsigned int pinlv=0;
unsigned int a1=0;//万位
unsigned int a2=0;//千位
unsigned int a3=0;//百位
unsigned int a4=0;//十位
unsigned int a5=0;//个位
unsigned int b;
unsigned char c;
unsigned
char1[10]={0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9};
unsigned
char2[10]={0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9};
unsigned
char3[10]={0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9};
unsigned
char4[10]={0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9};
unsigned
char5[10]={0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9};
void time() interrupt 1
{
TH0=0xdc;
TL0=0x00;
n++;
if(n==100)
{
n=0;
pinlv=TH1*256+TL1;//计算频率值
TH1=0;
TL1=0;
a5=pinlv%10;
b=pinlv/10;
a4=b%10;
b=b/10;
a3=b%10;
b=b/10;
a2=b%10;
a1=b/10;
}
}
void main()
{
TMOD=0x51;
EA=1;
ET0=1;
TH0=0xdc;
TL0=0x00;
TH1=0;
TL1=0;
TR0=1;
TR1=1;
while(1)
{
c=char[a1];//这儿开始错了
P0=c;
c=char[a2];
P0=c;
c=char[a3];
P0=c;
c=char[a4];
P0=c;
c=char[a5];
P0=c;
}
}

#define a1 0

类型不一致吧