8051 Input

[anilmudulakar]

i think the program should be some thing like this....
#include<stdio.h>
#include<reg51.h>
void delay(int);
sbit inp_pin=P1^0;
void main()
{
P0=P1=P2=P3=0x00;
for(;
{
if(inp_pin==0)
{
P2=0x01; // assuming that u have connected the LED to pin no.21 of 8051;
delay(500);
}
if(inp_pin==1)
{
P2=0x00;
delay(500);
}
}
}

 

[mcs51mc]

if(inp_pin==0)
{
P2=0x01; // assuming that u have connected the LED to pin no.21 of 8051;
delay(500);
}
if(inp_pin==1)
{
P2=0x00;
delay(500);
}

Please allow me to repeat myself:

Why testing for 1 AND 0 on an input pin??
If it's not a 1 it has to be 0 or what else do you expect?? 0.5

Ever heard of the ELSE statement guys??