gistfile1.h

#define led_conduction 0xFF
#define dip_state 0
#define init_led_state 1
#define led_state 2
#define rev_led_state 3

char din, dip, state;
while (dip = read_dip()){
  switch (state){
    case dip_state:
      din == led_conduction ? state = dip_init : din = dip;
      break;
    case init_led_state:
      din = 0x01;
      state = led_state;
      break;
    case led_state:
      din == 0x80 ? state = rev_led_state : din << 1;
      dip != led_conduction ? state = dip_state;
      break;
    case rev_led_state:
      din == 0x01 ? state = led_state : din >> 1;
      dip != led_conduction ? state = dip_state;
      break;
  }
  set_din(din);
}