diff --git a/.coveragerc b/.coveragerc
index 7cfcacaaa2d..4b317feb12c 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -20,6 +20,7 @@ omit =
     homeassistant/components/light/hue.py
     homeassistant/components/sensor/systemmonitor.py
     homeassistant/components/sensor/sabnzbd.py
+    homeassistant/components/sensor/mysensors.py
     homeassistant/components/notify/pushbullet.py
     homeassistant/components/notify/pushover.py
     homeassistant/components/media_player/cast.py
diff --git a/.gitmodules b/.gitmodules
index ae38be7c61b..ca0b1f024b8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -19,3 +19,6 @@
 [submodule "homeassistant/external/nzbclients"]
         path = homeassistant/external/nzbclients
         url = https://github.com/jamespcole/home-assistant-nzb-clients.git
+[submodule "homeassistant/external/pymysensors"]
+	path = homeassistant/external/pymysensors
+	url = https://github.com/theolind/pymysensors
diff --git a/homeassistant/components/sensor/mysensors.py b/homeassistant/components/sensor/mysensors.py
new file mode 100644
index 00000000000..807ddb6b485
--- /dev/null
+++ b/homeassistant/components/sensor/mysensors.py
@@ -0,0 +1,138 @@
+"""
+homeassistant.components.sensor.mysensors
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+MySensors sensors.
+
+Config:
+  sensor:
+    - platform: mysensors
+      port: '/dev/ttyACM0'
+"""
+import logging
+
+# pylint: disable=no-name-in-module, import-error
+import homeassistant.external.pymysensors.mysensors.mysensors as mysensors
+import homeassistant.external.pymysensors.mysensors.const as const
+from homeassistant.helpers.entity import Entity
+
+from homeassistant.const import (
+    ATTR_BATTERY_LEVEL, EVENT_HOMEASSISTANT_STOP,
+    TEMP_CELCIUS, TEMP_FAHRENHEIT,
+    STATE_ON, STATE_OFF)
+
+CONF_PORT = "port"
+
+ATTR_NODE_ID = "node_id"
+ATTR_CHILD_ID = "child_id"
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """ Setup the mysensors platform. """
+
+    devices = {}    # keep track of devices added to HA
+    # Just assume celcius means that the user wants metric for now.
+    # It may make more sense to make this a global config option in the future.
+    is_metric = (hass.config.temperature_unit == TEMP_CELCIUS)
+
+    def sensor_update(update_type, nid):
+        """ Callback for sensor updates from the MySensors gateway. """
+        _LOGGER.info("sensor_update %s: node %s", update_type, nid)
+        sensor = gateway.sensors[nid]
+        if sensor.sketch_name is None:
+            return
+        if nid not in devices:
+            devices[nid] = {}
+
+        node = devices[nid]
+        new_devices = []
+        for child_id, child in sensor.children.items():
+            if child_id not in node:
+                node[child_id] = {}
+            for value_type, value in child.values.items():
+                if value_type not in node[child_id]:
+                    name = '{} {}.{}'.format(sensor.sketch_name, nid, child.id)
+                    node[child_id][value_type] = \
+                        MySensorsNodeValue(
+                            nid, child_id, name, value_type, is_metric)
+                    new_devices.append(node[child_id][value_type])
+                else:
+                    node[child_id][value_type].update_sensor(
+                        value, sensor.battery_level)
+
+        if new_devices:
+            _LOGGER.info("adding new devices: %s", new_devices)
+            add_devices(new_devices)
+
+    port = config.get(CONF_PORT)
+    if port is None:
+        _LOGGER.error("Missing required key 'port'")
+        return False
+
+    gateway = mysensors.SerialGateway(port, sensor_update)
+    gateway.start()
+    gateway.metric = is_metric
+
+    hass.bus.listen_once(EVENT_HOMEASSISTANT_STOP,
+                         lambda event: gateway.stop())
+
+
+class MySensorsNodeValue(Entity):
+    """ Represents the value of a MySensors child node. """
+    # pylint: disable=too-many-arguments
+    def __init__(self, node_id, child_id, name, value_type, metric):
+        self._name = name
+        self.node_id = node_id
+        self.child_id = child_id
+        self.battery_level = 0
+        self.value_type = value_type
+        self.metric = metric
+        self._value = ''
+
+    @property
+    def should_poll(self):
+        """ MySensor gateway pushes its state to HA.  """
+        return False
+
+    @property
+    def name(self):
+        """ The name of this sensor. """
+        return self._name
+
+    @property
+    def state(self):
+        """ Returns the state of the device. """
+        return self._value
+
+    @property
+    def unit_of_measurement(self):
+        """ Unit of measurement of this entity. """
+        if self.value_type == const.SetReq.V_TEMP:
+            return TEMP_CELCIUS if self.metric else TEMP_FAHRENHEIT
+        elif self.value_type == const.SetReq.V_HUM or \
+                self.value_type == const.SetReq.V_DIMMER or \
+                self.value_type == const.SetReq.V_LIGHT_LEVEL:
+            return '%'
+        return None
+
+    @property
+    def state_attributes(self):
+        """ Returns the state attributes. """
+        return {
+            ATTR_NODE_ID: self.node_id,
+            ATTR_CHILD_ID: self.child_id,
+            ATTR_BATTERY_LEVEL: self.battery_level,
+        }
+
+    def update_sensor(self, value, battery_level):
+        """ Update a sensor with the latest value from the controller. """
+        _LOGGER.info("%s value = %s", self._name, value)
+        if self.value_type == const.SetReq.V_TRIPPED or \
+           self.value_type == const.SetReq.V_ARMED:
+            self._value = STATE_ON if int(value) == 1 else STATE_OFF
+        else:
+            self._value = value
+        self.battery_level = battery_level
+        self.update_ha_state()
diff --git a/homeassistant/external/pymysensors b/homeassistant/external/pymysensors
new file mode 160000
index 00000000000..75e0f505715
--- /dev/null
+++ b/homeassistant/external/pymysensors
@@ -0,0 +1 @@
+Subproject commit 75e0f505715b0cbf5a38e63749ea1d6ccf90773a