diff --git a/doc/devices_classes_branch.txt b/doc/devices_classes_branch.txt
index 8ee52d7..3c2f38b 100644
--- a/doc/devices_classes_branch.txt
+++ b/doc/devices_classes_branch.txt
@@ -409,7 +409,10 @@
 --------------------------------------------------------------------------------
 TODO NEXT
 
-Code up join auto and join ask, and get tests passing.
+joinauto with join_ack is working
+
+Code up and test join_autoask
+
 
 
 
diff --git a/src/energenie/Devices.py b/src/energenie/Devices.py
index 5c3f07a..f7a2762 100644
--- a/src/energenie/Devices.py
+++ b/src/energenie/Devices.py
@@ -383,7 +383,9 @@
 
     def join_ack(self):
         """Send a join-ack to the real device"""
-        self.send_message("join ack") # TODO
+        msg = OpenThings.Message(header_mfrid=MFRID_ENERGENIE, header_productid=self.product_id, header_sensorid=self.device_id)
+        msg[OpenThings.PARAM_JOIN] = {"wr":False, "typeid":OpenThings.Value.UINT, "length":0}
+        self.send_message(msg)
 
     #def handle_message(self, payload):
     #override for any specific handling
diff --git a/src/energenie/OpenThings.py b/src/energenie/OpenThings.py
index 4f3f319..5b27efe 100644
--- a/src/energenie/OpenThings.py
+++ b/src/energenie/OpenThings.py
@@ -655,7 +655,7 @@
 				paramid = rec["paramid"]
 				if paramid == key:
 					return rec
-		raise RuntimeError("no paramid found for %s" % str(hex(key)))
+		raise KeyError("no paramid found for %s" % str(hex(key)))
 
 
 	def __setitem__(self, key, value):
diff --git a/src/energenie/Registry.py b/src/energenie/Registry.py
index 29a1b83..c6ff641 100644
--- a/src/energenie/Registry.py
+++ b/src/energenie/Registry.py
@@ -8,11 +8,14 @@
 
 import time
 try:
-    import Devices # python 2
+    # Python 2
+    import Devices
+    import OpenThings
 except ImportError:
-    from . import Devices # python 3
+    # Python 3
+    from . import Devices
+    from . import OpenThings
 
-import Devices
 
 directory = {}
 
@@ -294,7 +297,7 @@
         # default action is to drop message
         # override this method if you want special processing
 
-    def accept_device(self, address, message):
+    def accept_device(self, address, message, forward=True):
         print("accept_device:%s" % str(address))
         # At moment, intentionally assume everything is mfrid=Energenie
         product_id = address[1]
@@ -305,11 +308,13 @@
         self.router.add(address, ci)
 
         # Finally, forward the first message to the new device class instance
-        print("**** routing first message to class instance")
-        ci.incoming_message(message)
+        if forward:
+            print("**** routing first message to class instance")
+            ci.incoming_message(message)
 
         ##self.registry.list()
         ##self.router.list()
+        return ci # The new device class instance that we created
 
 
 class AutoDiscovery(Discovery):
@@ -341,13 +346,22 @@
         Discovery.__init__(self, registry, router)
 
     def unknown_device(self, address, message):
-        print("TODO: unknown device auto join %s" % str(address))
-        # if it is not a join req
-        #   route to unhandled message handler
-        # if it is a join req
-        #   accept the device
-        #   send join ack back to device (using new device class instance?)
-        pass #TODO
+        print("unknown device auto join %s" % str(address))
+
+        #TODO: need to make this work with correct meta methods
+        ##if not OpenThings.PARAM_JOIN in message:
+        try:
+            j = message[OpenThings.PARAM_JOIN]
+        except KeyError:
+            j = None
+
+        if j == None: # not a join
+            self.unknown_device(address, message)
+        else: # it is a join
+            # but don't forward the join request as it will be malformed with no value
+            ci = self.accept_device(address, message, forward=False)
+            ci.join_ack() # Ask new class instance to send a join_ack back to physical device
+            #TODO: MiHomeDevice needs this join_ack() added to it
 
 
 class JoinConfirmedDiscovery(Discovery):
diff --git a/src/energenie/Registry_test.py b/src/energenie/Registry_test.py
index 3a38177..2cdf0a1 100644
--- a/src/energenie/Registry_test.py
+++ b/src/energenie/Registry_test.py
@@ -145,9 +145,10 @@
 
         # Poke synthetic unknown JOIN into the router and let it route to unknown handler
         self.msg = OpenThings.Message(header_mfrid=Devices.MFRID_ENERGENIE,
-                                      header_productid=Devices.MIHO005,
+                                      header_productid=Devices.PRODUCTID_MIHO005,
                                       header_sensorid=UNKNOWN_SENSOR_ID)
         self.msg[OpenThings.PARAM_JOIN] = {}
+        ##print(self.msg)
 
         fsk_router.incoming_message(
             (Devices.MFRID_ENERGENIE, Devices.PRODUCTID_MIHO005, UNKNOWN_SENSOR_ID), self.msg)