#include <avr/io.h>
#include <util/delay.h>

int main (void)
{

 DDRA = 0b10000000; // MAKE PA7 an output
DDRB = 0; //make all of port B inputs

//enable the internal pull-up resistor on PB2

 while(1) {
  PORTA = 255;
_delay_ms(1000); // LED ON
  PORTA = 0;  
_delay_ms(1000); // LED OFF
 }

 return 0;
}