AVR-Chat

Read the data sheet for your part 
But this is my understanding.

Working with port B

Set port B to output and output a logical high to pin 0
DDRB = 0xFF;
PORTB |= 1;

Set port B pin 0 to input with pullup register on
PORTB |= 1;
DDRB = 0xFE;

Set port B pin 0 to input with pullup register off
PORTB |= 1;
DDRB = 0xFF;


Read port B pin 0

Myvar = (PINB & 1); 


Summary
Set DDRB to 1 for output 0 for input
For input write a 1 to that pin to enable pullup 0 to disable pullup
The PINB can be used to read the port at anytime. 

Hope this helps

-----Original Message-----
From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On
Behalf Of aswinefy2003
Sent: Tuesday, August 09, 2005 12:40 AM
To: AVR-Chat@yahoogroups.com
Subject: [AVR-Chat] help/reading I/0 pins


Hello

         Can any one give a sample code for 
 reading the value of  a i/o PIN. Also tell 
me role of pull up resistor in doiing so.       








 
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