Now we will control the LED depending on external input. In this tutorial we will interface a switch to one of the port pin and display its status on LED connected to other port.

Basics

For this tutorial we will a connect a switch to PORT A0 and LED to PORT C0 of Atmega32. W will configure PORT A0 as input to read the switch status and PORT C0 as outputto display the switch status on LED.
Refer the AVR I/O Register Configuration tutorial for basics of GPIO register configuration.