DSMR sensor (#4309)

* Initial implemenation of DSMR component.

* Fix linting

* Remove protocol V2.2 support until merged upstream.

* Generate requirements using script.

* Use updated dsmr-parser with protocol 2.2 support.

* Add tests.

* Isort and input validation.

* Add entities for gas and actual meter reading. Error handling. Use Throttle.

* Implement non-blocking serial reader.

* Improve logging.

* Merge entities into one, add icons, fix tests for asyncio.

* Add error logging for serial reader.

* Refactoring and documentation.

- refactor asyncio reader task to make sure it stops with HA
- document general principle of this component
- refactor entity reading to be more clear
- remove cruft from split entity implementation

* Use `port` configuration key.

* DSMR V2.2 seems to conflict in explaining which tariff is high and low.

http://www.netbeheernederland.nl/themas/hotspot/hotspot-documenten/?dossierid=11010056&title=Slimme%20meter&onderdeel=Documenten
> DSMR v2.2 Final P1
>> 6.1: table vs table note

    Meter Reading electricity delivered to client normal tariff) in 0,01 kWh - 1-0:1.8.1.255
    Meter Reading electricity delivered to client (low tariff) in 0,01 kWh - 1-0:1.8.2.255

    Note: Tariff code 1 is used for low tariff and tariff code 2 is used for normal tariff.

* Refactor to use asyncio.Protocol instead of loop+queue.

* Fix requirements

* Close transport when HA stops.

* Cleanup.

* Include as dependency for testing (until merged upstream.)

* Fix style.

* Update setup.cfg

homeassistant/components/sensor/dsmr.py

@@ -0,0 +1,179 @@
+"""
+Support for Dutch Smart Meter Requirements.
+
+Also known as: Smartmeter or P1 port.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/sensor.dsmr/
+
+Technical overview:
+
+DSMR is a standard to which Dutch smartmeters must comply. It specifies that
+the smartmeter must send out a 'telegram' every 10 seconds over a serial port.
+
+The contents of this telegram differ between version but they generally consist
+of lines with 'obis' (Object Identification System, a numerical ID for a value)
+followed with the value and unit.
+
+This module sets up a asynchronous reading loop using the `dsmr_parser` module
+which waits for a complete telegram, parser it and puts it on an async queue as
+a dictionary of `obis`/object mapping. The numeric value and unit of each value
+can be read from the objects attributes. Because the `obis` are know for each
+DSMR version the Entities for this component are create during bootstrap.
+
+Another loop (DSMR class) is setup which reads the telegram queue,
+stores/caches the latest telegram and notifies the Entities that the telegram
+has been updated.
+"""
+
+import asyncio
+import logging
+from datetime import timedelta
+
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.components.sensor import PLATFORM_SCHEMA
+from homeassistant.const import CONF_PORT, EVENT_HOMEASSISTANT_STOP
+from homeassistant.helpers.entity import Entity
+
+DOMAIN = 'dsmr'
+
+REQUIREMENTS = [
+    'https://github.com/aequitas/dsmr_parser/archive/async_protocol.zip'
+    '#dsmr_parser==0.4'
+]
+
+# Smart meter sends telegram every 10 seconds
+MIN_TIME_BETWEEN_UPDATES = timedelta(seconds=10)
+
+CONF_DSMR_VERSION = 'dsmr_version'
+DEFAULT_PORT = '/dev/ttyUSB0'
+DEFAULT_DSMR_VERSION = '2.2'
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Optional(CONF_PORT, default=DEFAULT_PORT): cv.string,
+    vol.Optional(CONF_DSMR_VERSION, default=DEFAULT_DSMR_VERSION): vol.All(
+        cv.string, vol.In(['4', '2.2'])),
+})
+
+_LOGGER = logging.getLogger(__name__)
+
+ICON_POWER = 'mdi:flash'
+ICON_GAS = 'mdi:fire'
+
+
+@asyncio.coroutine
+def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
+    """Setup DSMR sensors."""
+    # suppres logging
+    logging.getLogger('dsmr_parser').setLevel(logging.ERROR)
+
+    from dsmr_parser import obis_references as obis
+    from dsmr_parser.protocol import create_dsmr_reader
+
+    dsmr_version = config[CONF_DSMR_VERSION]
+
+    # define list of name,obis mappings to generate entities
+    obis_mapping = [
+        ['Power Consumption', obis.CURRENT_ELECTRICITY_USAGE],
+        ['Power Production', obis.CURRENT_ELECTRICITY_DELIVERY],
+        ['Power Tariff', obis.ELECTRICITY_ACTIVE_TARIFF],
+        ['Power Consumption (low)', obis.ELECTRICITY_USED_TARIFF_1],
+        ['Power Consumption (normal)', obis.ELECTRICITY_USED_TARIFF_2],
+        ['Power Production (low)', obis.ELECTRICITY_DELIVERED_TARIFF_1],
+        ['Power Production (normal)', obis.ELECTRICITY_DELIVERED_TARIFF_2],
+    ]
+    # protocol version specific obis
+    if dsmr_version == '4':
+        obis_mapping.append(['Gas Consumption', obis.HOURLY_GAS_METER_READING])
+    else:
+        obis_mapping.append(['Gas Consumption', obis.GAS_METER_READING])
+
+    # generate device entities
+    devices = [DSMREntity(name, obis) for name, obis in obis_mapping]
+
+    # setup devices
+    yield from async_add_devices(devices)
+
+    def update_entities_telegram(telegram):
+        """Update entities with latests telegram & trigger state update."""
+        # make all device entities aware of new telegram
+        for device in devices:
+            device.telegram = telegram
+            hass.async_add_job(device.async_update_ha_state)
+
+    # creates a asyncio.Protocol for reading DSMR telegrams from serial
+    # and calls update_entities_telegram to update entities on arrival
+    dsmr = create_dsmr_reader(config[CONF_PORT], config[CONF_DSMR_VERSION],
+                              update_entities_telegram, loop=hass.loop)
+
+    # start DSMR asycnio.Protocol reader
+    transport, _ = yield from hass.loop.create_task(dsmr)
+
+    hass.bus.async_listen_once(EVENT_HOMEASSISTANT_STOP, transport.close)
+
+
+class DSMREntity(Entity):
+    """Entity reading values from DSMR telegram."""
+
+    def __init__(self, name, obis):
+        """"Initialize entity."""
+        # human readable name
+        self._name = name
+        # DSMR spec. value identifier
+        self._obis = obis
+        self.telegram = {}
+
+    def get_dsmr_object_attr(self, attribute):
+        """Read attribute from last received telegram for this DSMR object."""
+        # make sure telegram contains an object for this entities obis
+        if self._obis not in self.telegram:
+            return None
+
+        # get the attibute value if the object has it
+        dsmr_object = self.telegram[self._obis]
+        return getattr(dsmr_object, attribute, None)
+
+    @property
+    def name(self):
+        """Return the name of the sensor."""
+        return self._name
+
+    @property
+    def icon(self):
+        """Icon to use in the frontend, if any."""
+        if 'Power' in self._name:
+            return ICON_POWER
+        elif 'Gas' in self._name:
+            return ICON_GAS
+
+    @property
+    def state(self):
+        """Return the state of sensor, if available, translate if needed."""
+        from dsmr_parser import obis_references as obis
+
+        value = self.get_dsmr_object_attr('value')
+
+        if self._obis == obis.ELECTRICITY_ACTIVE_TARIFF:
+            return self.translate_tariff(value)
+        else:
+            return value
+
+    @property
+    def unit_of_measurement(self):
+        """Return the unit of measurement of this entity, if any."""
+        return self.get_dsmr_object_attr('unit')
+
+    @staticmethod
+    def translate_tariff(value):
+        """Convert 2/1 to normal/low."""
+        # DSMR V2.2: Note: Tariff code 1 is used for low tariff
+        # and tariff code 2 is used for normal tariff.
+
+        if value == '0002':
+            return 'normal'
+        elif value == '0001':
+            return 'low'
+        else:
+            return None