diff --git a/homeassistant/components/sensor/mqtt.py b/homeassistant/components/sensor/mqtt.py
index c3d4910b527..f12df688385 100644
--- a/homeassistant/components/sensor/mqtt.py
+++ b/homeassistant/components/sensor/mqtt.py
@@ -8,20 +8,19 @@ import logging
 
 import voluptuous as vol
 
-import homeassistant.components.mqtt as mqtt
+from homeassistant.components.mqtt import CONF_STATE_TOPIC, CONF_QOS
 from homeassistant.const import (
     CONF_NAME, CONF_VALUE_TEMPLATE, STATE_UNKNOWN, CONF_UNIT_OF_MEASUREMENT)
-from homeassistant.components.mqtt import CONF_STATE_TOPIC, CONF_QOS
-import homeassistant.helpers.config_validation as cv
-from homeassistant.helpers.entity import Entity
 from homeassistant.helpers import template
+from homeassistant.helpers.entity import Entity
+import homeassistant.components.mqtt as mqtt
+import homeassistant.helpers.config_validation as cv
 
 _LOGGER = logging.getLogger(__name__)
 
+DEFAULT_NAME = 'MQTT Sensor'
 DEPENDENCIES = ['mqtt']
 
-DEFAULT_NAME = "MQTT Sensor"
-
 PLATFORM_SCHEMA = mqtt.MQTT_RO_PLATFORM_SCHEMA.extend({
     vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
     vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string,
@@ -33,9 +32,9 @@ def setup_platform(hass, config, add_devices, discovery_info=None):
     """Setup MQTT Sensor."""
     add_devices([MqttSensor(
         hass,
-        config[CONF_NAME],
-        config[CONF_STATE_TOPIC],
-        config[CONF_QOS],
+        config.get(CONF_NAME),
+        config.get(CONF_STATE_TOPIC),
+        config.get(CONF_QOS),
         config.get(CONF_UNIT_OF_MEASUREMENT),
         config.get(CONF_VALUE_TEMPLATE),
     )])
diff --git a/homeassistant/components/sensor/mqtt_room.py b/homeassistant/components/sensor/mqtt_room.py
index 6980b7e6f7b..a640d1e5268 100644
--- a/homeassistant/components/sensor/mqtt_room.py
+++ b/homeassistant/components/sensor/mqtt_room.py
@@ -11,7 +11,8 @@ import voluptuous as vol
 
 import homeassistant.components.mqtt as mqtt
 from homeassistant.components.sensor import PLATFORM_SCHEMA
-from homeassistant.const import CONF_NAME, STATE_UNKNOWN
+from homeassistant.const import (
+    CONF_NAME, STATE_UNKNOWN, CONF_TIMEOUT)
 from homeassistant.components.mqtt import CONF_STATE_TOPIC
 import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity import Entity
@@ -21,12 +22,18 @@ _LOGGER = logging.getLogger(__name__)
 
 DEPENDENCIES = ['mqtt']
 
-CONF_DEVICE_ID = 'device_id'
-CONF_TIMEOUT = 'timeout'
+ATTR_DEVICE_ID = 'device_id'
+ATTR_DISTANCE = 'distance'
+ATTR_ID = 'id'
+ATTR_ROOM = 'room'
+
+CONF_DEVICE_ID = 'device_id'
+CONF_ROOM = 'room'
 
-DEFAULT_TOPIC = 'room_presence'
-DEFAULT_TIMEOUT = 5
 DEFAULT_NAME = 'Room Sensor'
+DEFAULT_TIMEOUT = 5
+DEFAULT_TOPIC = 'room_presence'
+DEPENDENCIES = ['mqtt']
 
 PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
     vol.Required(CONF_DEVICE_ID): cv.string,
@@ -36,15 +43,15 @@ PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
 })
 
 MQTT_PAYLOAD = vol.Schema(vol.All(json.loads, vol.Schema({
-    vol.Required('id'): cv.string,
-    vol.Required('distance'): vol.Coerce(float)
+    vol.Required(ATTR_ID): cv.string,
+    vol.Required(ATTR_DISTANCE): vol.Coerce(float),
 }, extra=vol.ALLOW_EXTRA)))
 
 
 # pylint: disable=unused-argument
-def setup_platform(hass, config, add_devices_callback, discovery_info=None):
+def setup_platform(hass, config, add_devices, discovery_info=None):
     """Setup MQTT Sensor."""
-    add_devices_callback([MQTTRoomSensor(
+    add_devices([MQTTRoomSensor(
         hass,
         config.get(CONF_NAME),
         config.get(CONF_STATE_TOPIC),
@@ -62,7 +69,7 @@ class MQTTRoomSensor(Entity):
         self._state = STATE_UNKNOWN
         self._hass = hass
         self._name = name
-        self._state_topic = state_topic + '/+'
+        self._state_topic = '{}{}'.format(state_topic, '/+')
         self._device_id = slugify(device_id).upper()
         self._timeout = timeout
         self._distance = None
@@ -86,7 +93,7 @@ class MQTTRoomSensor(Entity):
                 return
 
             device = _parse_update_data(topic, data)
-            if device.get('device_id') == self._device_id:
+            if device.get(CONF_DEVICE_ID) == self._device_id:
                 if self._distance is None or self._updated is None:
                     update_state(**device)
                 else:
@@ -95,8 +102,8 @@ class MQTTRoomSensor(Entity):
                     # device is closer to another room OR
                     # last update from other room was too long ago
                     timediff = dt.utcnow() - self._updated
-                    if device.get('room') == self._state \
-                            or device.get('distance') < self._distance \
+                    if device.get(ATTR_ROOM) == self._state \
+                            or device.get(ATTR_DISTANCE) < self._distance \
                             or timediff.seconds >= self._timeout:
                         update_state(**device)
 
@@ -116,7 +123,7 @@ class MQTTRoomSensor(Entity):
     def device_state_attributes(self):
         """Return the state attributes."""
         return {
-            'distance': self._distance
+            ATTR_DISTANCE: self._distance
         }
 
     @property
@@ -129,11 +136,11 @@ def _parse_update_data(topic, data):
     """Parse the room presence update."""
     parts = topic.split('/')
     room = parts[-1]
-    device_id = slugify(data.get('id')).upper()
+    device_id = slugify(data.get(ATTR_ID)).upper()
     distance = data.get('distance')
     parsed_data = {
-        'device_id': device_id,
-        'room': room,
-        'distance': distance
+        ATTR_DEVICE_ID: device_id,
+        ATTR_ROOM: room,
+        ATTR_DISTANCE: distance
     }
     return parsed_data
diff --git a/homeassistant/const.py b/homeassistant/const.py
index 7b61daa1c8e..4812f2f87e1 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -61,6 +61,7 @@ CONF_AUTHENTICATION = 'authentication'
 CONF_BEFORE = 'before'
 CONF_BELOW = 'below'
 CONF_BLACKLIST = 'blacklist'
+CONF_BRIGHTNESS = 'brightness'
 CONF_CODE = 'code'
 CONF_COMMAND = 'command'
 CONF_COMMAND_CLOSE = 'command_close'
@@ -110,6 +111,7 @@ CONF_PREFIX = 'prefix'
 CONF_RECIPIENT = 'recipient'
 CONF_RESOURCE = 'resource'
 CONF_RESOURCES = 'resources'
+CONF_RGB = 'rgb'
 CONF_SCAN_INTERVAL = 'scan_interval'
 CONF_SENDER = 'sender'
 CONF_SENSOR_CLASS = 'sensor_class'
@@ -120,6 +122,7 @@ CONF_STRUCTURE = 'structure'
 CONF_SWITCHES = 'switches'
 CONF_TEMPERATURE_UNIT = 'temperature_unit'
 CONF_TIME_ZONE = 'time_zone'
+CONF_TIMEOUT = 'timeout'
 CONF_TOKEN = 'token'
 CONF_TRIGGER_TIME = 'trigger_time'
 CONF_UNIT_OF_MEASUREMENT = 'unit_of_measurement'