Add precision parameter to dsmr sensor

homeassistant/components/sensor/dsmr.py

@@ -24,9 +24,12 @@
 
 CONF_DSMR_VERSION = 'dsmr_version'
 CONF_RECONNECT_INTERVAL = 'reconnect_interval'
+CONF_PRECISION = 'precision'
 
 DEFAULT_DSMR_VERSION = '2.2'
 DEFAULT_PORT = '/dev/ttyUSB0'
+DEFAULT_PRECISION = 3
+
 DOMAIN = 'dsmr'
 
 ICON_GAS = 'mdi:fire'
@@ -45,6 +48,7 @@
     vol.Optional(CONF_DSMR_VERSION, default=DEFAULT_DSMR_VERSION): vol.All(
         cv.string, vol.In(['5', '4', '2.2'])),
     vol.Optional(CONF_RECONNECT_INTERVAL, default=30): int,
+    vol.Optional(CONF_PRECISION, default=DEFAULT_PRECISION): vol.Coerce(int),
 })
 
 
@@ -146,7 +150,7 @@ async def async_setup_platform(hass, config, async_add_entities,
     ]
 
     # Generate device entities
-    devices = [DSMREntity(name, obis) for name, obis in obis_mapping]
+    devices = [DSMREntity(name, obis, config) for name, obis in obis_mapping]
 
     # Protocol version specific obis
     if dsmr_version in ('4', '5'):
@@ -156,8 +160,8 @@ async def async_setup_platform(hass, config, async_add_entities,
 
     # Add gas meter reading and derivative for usage
     devices += [
-        DSMREntity('Gas Consumption', gas_obis),
-        DerivativeDSMREntity('Hourly Gas Consumption', gas_obis),
+        DSMREntity('Gas Consumption', gas_obis, config),
+        DerivativeDSMREntity('Hourly Gas Consumption', gas_obis, config),
     ]
 
     async_add_entities(devices)
@@ -224,10 +228,11 @@ async def connect_and_reconnect():
 class DSMREntity(Entity):
     """Entity reading values from DSMR telegram."""
 
-    def __init__(self, name, obis):
+    def __init__(self, name, obis, config):
         """Initialize entity."""
         self._name = name
         self._obis = obis
+        self._config = config
         self.telegram = {}
 
     def get_dsmr_object_attr(self, attribute):
@@ -267,6 +272,11 @@ def state(self):
         if self._obis == obis.ELECTRICITY_ACTIVE_TARIFF:
             return self.translate_tariff(value)
 
+        try:
+            value = round(float(value),self._config[CONF_PRECISION])
+        except:
+            value = value
+
         if value is not None:
             return value