diff --git a/doc/devices_classes_branch.txt b/doc/devices_classes_branch.txt
index 8c954df..d22347d 100644
--- a/doc/devices_classes_branch.txt
+++ b/doc/devices_classes_branch.txt
@@ -409,23 +409,30 @@
 TODO NEXT
 
 DONE
-* provide a way that a device class instance can have a registered callback
-  that passes the message that has just been handled, but without loosing
-  the reading update. The main purpose of this is for logging and notification
-  that new data has arrived (for event driven handling instead of polling)
-
-
-
-
 * implement neater unknown message handler in the router
   do it as a callback rather than overwriting the default method
 
+
+
+* consider a callback in the router for new_data, for all messages
+  regardless of if known or not (good for generic data logging)
+
 * design a way that a MIHO005 class instance can be auto generated from a product_id field
 
-* provide an option in the router to turn on or off auto device registration
-  on unknown message (poor mans discovery)
+----
 
-* Make auto registration also add an auto route
+* implement auto device registration in the router (poor mans discovery)
+  when a message comes from an unknown sensorid,
+  build a device class instance wrapper for it
+  put it in the registry
+  knit it to the router
+  then call it's receive handler
+
+* make the above auto device registration optional with a config flag in router
+
+* Write discovery properly as a service in Registry
+  When an unknown device is found, add it to the registry
+  if the discovery process is enabled, and route it's address.
 
 ----
 
@@ -435,16 +442,12 @@
 
 ----
 
-* Write discovery properly as a service in Registry
-  When an unknown device is found, add it to the registry
-  if the discovery process is enabled, and route it's address.
+Consider whether there is a need for a general update notify
+mechanism - perhaps could have a message sequence counter that
+you poll, and if it is higher than last time, you know the
+device state has updated (independently of using the
+when_updated callback)
 
-----
-
-* look at if we need some when_x_updated() methods on device
-  classes, even just a generic callback that is called when
-  data has been updated. Consider if there are multiple
-  consumers of this data (multiple callback targets)
 
 ----
 
diff --git a/src/energenie/Registry.py b/src/energenie/Registry.py
index 0179871..503d457 100644
--- a/src/energenie/Registry.py
+++ b/src/energenie/Registry.py
@@ -232,6 +232,7 @@
     def __init__(self, name):
         self.name = name # probably FSK or OOK
         self.routes = {} # key(tuple of ids) -> value(device class instance)
+        self.unknown_cb = None
 
     def add(self, address, instance):
         """Add this device instance to the routing table"""
@@ -248,17 +249,28 @@
         else: # unknown address
             self.handle_unknown(address, payload)
 
+    def when_unknown(self, callback):
+        """Register a callback for unknown messages"""
+        #NOTE: this is the main hook point for auto discovery and registration
+        self.unknown_cb = callback
+
     def handle_unknown(self, address, payload):
-        #TODO: route to something that handles unknown addresses, e.g. discovery agent
-        #discovery agent could be configured by overriding handle_unknown at construction time, below
-        print("unknown address: %s" % address)
-        print("ignored payload: %s" % payload)
+        if self.unknown_cb != None:
+            self.unknown_cb(address, payload)
+        else:
+            # Default action is just a debug message, and drop the payload
+            print("Unknown address: %s" % str(address))
 
 
+# Might rename these, especially when we add in other protocols
+# such as devices that are 868 wirefree doorbells etc.
+
+#TODO: Name is not completely representative of function.
+# This is the Energenie 433.92MHz with OpenThings
 fsk_router = Router("fsk")
+
 #OOK receive not yet written
+#It will be used to be able to learn codes from Energenie legacy hand remotes
 ##ook_router = Router("ook")
 
-
-
 # END
diff --git a/src/monitor_mihome.py b/src/monitor_mihome.py
index 9f811cb..86fc073 100644
--- a/src/monitor_mihome.py
+++ b/src/monitor_mihome.py
@@ -23,22 +23,20 @@
     energenie.registry.add(purple, "purple")
     energenie.fsk_router.add((energenie.Devices.MFRID_ENERGENIE, energenie.Devices.PRODUCTID_MIHO005, MY_SENSOR_ID), purple)
 
+    # Register for update callbacks when a new message comes in for the purple device
+    # This is a useful way to add data logging on a per-device basis
     def new_data(self, message):
-        print("new data for %s" % self)
+        print("\nnew data for %s" % self)
         message.dump()
         Logger.logMessage(message)
     purple.when_updated(new_data)
 
     # Override the default unknown handler, so we can show data from unregistered devices
-    def unk(address, message):
-        print("Unknown device:%s" % str(hex(address[2])))
+    # This is a useful hook point for later adding device discovery
+    def unknown(address, message):
+        print("\nUnknown device:%s" % str(hex(address[2])))
         message.dump()
-        #TODO: add device to registry and to fsk_router table
-        #note: requires auto class create from product_id to be working first
-        Logger.logMessage(message)
-    energenie.fsk_router.handle_unknown = unk
-    #TODO: Provide a better callback registration scheme
-    ##energenie.fsk_router.when_unknown(unk)
+    energenie.fsk_router.when_unknown(unknown)
 
     try:
         while True: