void initPortB()
{
  DDRB = 0x20; // set PortB to output
  PORTB = 0x00;
}

void initTimer0()
{
  TCCR0A = 0x00;
  TCCR0B = 0x05; // timer 0 start; prescaler 1024;
  TIMSK0 = 0x01;
}