Index: dialin/ui/hd_simulator.py
===================================================================
diff -u -r6b32185c35ac0a95013189cc3bf77c08ed4b6a96 -r0f182516739bda0dde1e69f62d31a107d154a3fc
--- dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 6b32185c35ac0a95013189cc3bf77c08ed4b6a96)
+++ dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 0f182516739bda0dde1e69f62d31a107d154a3fc)
@@ -15,6 +15,7 @@
 ############################################################################
 import enum
 from time import sleep
+from typing import Callable
 
 from . import messageBuilder
 from ..common import *
@@ -54,6 +55,7 @@
         super().__init__()
         HDSimulator.instance_count = HDSimulator.instance_count + 1
 
+        self.auto_response = auto_response
         self._log_manager = LogManager(log_level=log_level, log_filepath=self.__class__.__name__ + ".log")
         self.logger = self._log_manager.logger
         self.console_out = console_out
@@ -103,6 +105,24 @@
         # initialize variables that will be populated by UI version response
         self.ui_version = None
 
+    def add_publication(self, channel_id: DenaliChannels, message_id: MsgIds, function_ptr: Callable) -> None:
+        """
+        Allows later addition of publication to the HDSimulator
+        @param channel_id: (DenaliChannels) the channel id of the message
+        @param message_id: (MsgIds) the message id
+        @param function_ptr: (Callable) the pointer to the message handler function
+        @return: None
+        """
+        if self.auto_response:
+            if channel_id > 0 and message_id != MsgIds.MSG_ID_UNUSED and function_ptr is not None:
+                self.can_interface.register_receiving_publication_function(channel_id,
+                                                                           message_id,
+                                                                           function_ptr)
+            else:
+                self.logger.debug("rejected publication registration {0}, {1}, {2}".format(channel_id,
+                                                                                           message_id,
+                                                                                           function_ptr))
+
     def get_ui_version(self):
         """
         Gets the ui version
@@ -304,31 +324,6 @@
 
         self.cmd_send_uf_treatment_response(1, 0, uf_volume)
 
-    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 simulator ) within 2 sec it means it has been stopped,
-        # so do the check-in again.
-        if now - self.checked_in_last > 5:
-            self.checked_in = False
-
-        self.checked_in_last = now
-
-        if self.checked_in:
-            return
-
-        self.cmd_send_power_on_self_test_version_request()
-        for i in range(20):
-            self.cmd_send_hd_post(i, True, False)
-            sleep(0.1)
-        self.cmd_send_hd_post(0, True, True)
-        self.cmd_send_hd_operation_mode(4, 0)
-        self.checked_in = True
-
     def _handler_ui_initiate_treatment(self, message):
         """
         Handler function to start a treatment
Index: dialin/ui/unittests.py
===================================================================
diff -u -radae506afce35a0063c6c2baf7e8580986f3bee7 -r0f182516739bda0dde1e69f62d31a107d154a3fc
--- dialin/ui/unittests.py	(.../unittests.py)	(revision adae506afce35a0063c6c2baf7e8580986f3bee7)
+++ dialin/ui/unittests.py	(.../unittests.py)	(revision 0f182516739bda0dde1e69f62d31a107d154a3fc)
@@ -14,9 +14,9 @@
 #
 ############################################################################
 
-import test
 import sys
 
+from squish import *
 from dialin.ui import crc
 from dialin.ui.utils import check_can0