/*
 Toggle a on-board led if push button is pressed

*/

#include <avr/io.h>

void init_io()
{

 DDRB |= 1<<PB4; //Setting the pin as output
 DDRB &= ~(1<<PB3); //Setting the pin as input

}

int is_button_pressed()
{
 return (PINB
 &(1<<PB3)) ;
}

void toggle_led()
{
 PORTB ^= 1<<PB4;
}

int main()
{

 init_io();

 while(1){
  if(is_button_pressed())
   toggle_led();
 }


 return 0;

}