Index: dialin/ui/hd_simulator.py
===================================================================
diff -u -re0ee1c47b7d49ff63855c1c5c2f35a0ab52b822d -ra0f6037ac5b71cc79554622e1a3406bfba12e795
--- dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision e0ee1c47b7d49ff63855c1c5c2f35a0ab52b822d)
+++ dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision a0f6037ac5b71cc79554622e1a3406bfba12e795)
@@ -42,7 +42,7 @@
     def __init__(self, can_interface: str = "can0",
                  log_level: bool = None,
                  console_out: bool = False,
-                 passive_mode: bool = False,
+                 passive_mode: bool = True,
                  auto_response: bool = False):
         """
         The HDSimulator constructor
@@ -310,16 +310,15 @@
 
         self.cmd_send_uf_treatment_response(1, 0, uf_volume)
 
-    def _handler_ui_first_check_in(self, message)->None:
+    def _handler_ui_first_check_in(self, message) -> None:
         """
         Handler function to first check in to start the post
         @param message: the check-in message
         @return: None
         """
         now = time.time()
-        # if the application is not checking-in (the simulatoe ) within 2 sec it means it has been stopped,
+        # if the application is not checking-in (the simulator ) within 2 sec it means it has been stopped,
         # so do the check-in again.
-        print("check-in: ", now, now - self.checked_in_last)
         if now - self.checked_in_last > 5:
             self.checked_in = False
 
@@ -328,7 +327,6 @@
         if self.checked_in:
             return
 
-        print("_handler_ui_first_check_in")
         self.cmd_send_power_on_self_test_version_request()
         for i in range(20):
             self.cmd_send_hd_post(i, True, False)
@@ -1938,21 +1936,19 @@
         @param message: The ui version response message
         @return: None
         """
-        major = struct.unpack('B', bytearray(
-            message['message'][self.START_POS_MAJOR:self.END_POS_MAJOR]))
-        minor = struct.unpack('B', bytearray(
-            message['message'][self.START_POS_MINOR:self.END_POS_MINOR]))
-        micro = struct.unpack('B', bytearray(
-            message['message'][self.START_POS_MICRO:self.END_POS_MICRO]))
-        build = struct.unpack('H', bytearray(
-            message['message'][self.START_POS_BUILD:self.END_POS_BUILD]))
-        compatibility = struct.unpack('H', bytearray(
-            message['message'][self.START_POS_COMPAT:self.END_POS_COMPAT]))
+        payload = message['message']
+        index = DenaliMessage.PAYLOAD_START_INDEX
+        major, index = bytearray_to_byte(payload, index, False)
+        minor, index = bytearray_to_byte(payload, index, False)
+        micro, index = bytearray_to_byte(payload, index, False)
+        build, index = bytearray_to_short(payload, index, False)
+        compt, index = bytearray_to_integer(payload, index, False)
 
-        if all([len(each) > 0 for each in [major, minor, micro, build]]):
-            self.ui_version = f"v{major[0]}.{minor[0]}.{micro[0]}-{build[0]}-{compatibility[0]}"
-            self.logger.debug(f"UI VERSION: {self.ui_version}")
+        self.ui_version = f"v{major}.{minor}.{micro}-{build},{compt}"
+        self.logger.debug(f"UI VERSION: {self.ui_version}")
 
+        print("version: ", self.ui_version)
+
     def cmd_send_hd_request_ui_version(self) -> None:
         """
         send HD request for UI version