i want ti interface an IR

[D.V.G. Krishna]

i want ti interface an IR sensor to atmega16

the sensor is active high

if i write

DDRD=0x00;

PORTD=0xff;

 

the pins will be by default high

when sensor detects object it gives high

the mc cannot detact a change in input

 

can i write PORTD=0x00;

what will happen?????????