protocol.c

if(sum < threshold) { 
  if(signal_length) { 
    if(signal_length > 10) { 
      if(bit != 0) printf("(?)"); 
        bit = 0; 
        signal_length = 0; 
      } else { 
        bit_data = 2 * bit_data + (signal_length < 6); 
        if(++bit == 8) { 
          printf("%c", bit_data); 
          fflush(NULL); 
          bit = 0; 
        } 
      } 
      signal_length = 0; 
    } 
  } else { 
  signal_length++; 
}