Add linux battery sensor (#3238)

.coveragerc

@@ -225,6 +225,7 @@ omit =
     homeassistant/components/sensor/hp_ilo.py
     homeassistant/components/sensor/imap.py
     homeassistant/components/sensor/lastfm.py
+    homeassistant/components/sensor/linux_battery.py
     homeassistant/components/sensor/loopenergy.py
     homeassistant/components/sensor/mhz19.py
     homeassistant/components/sensor/mqtt_room.py

homeassistant/components/sensor/linux_battery.py

@@ -0,0 +1,125 @@
+"""
+Details about the built-in battery.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/sensor.linux_battery/
+"""
+import logging
+import os
+
+import voluptuous as vol
+
+from homeassistant.components.sensor import PLATFORM_SCHEMA
+from homeassistant.const import CONF_NAME
+from homeassistant.helpers.entity import Entity
+import homeassistant.helpers.config_validation as cv
+
+REQUIREMENTS = ['batinfo==0.3']
+
+_LOGGER = logging.getLogger(__name__)
+
+ATTR_NAME = 'name'
+ATTR_PATH = 'path'
+ATTR_ALARM = 'alarm'
+ATTR_CAPACITY = 'capacity'
+ATTR_CAPACITY_LEVEL = 'capacity_level'
+ATTR_CYCLE_COUNT = 'cycle_count'
+ATTR_ENERGY_FULL = 'energy_full'
+ATTR_ENERGY_FULL_DESIGN = 'energy_full_design'
+ATTR_ENERGY_NOW = 'energy_now'
+ATTR_MANUFACTURER = 'manufacturer'
+ATTR_MODEL_NAME = 'model_name'
+ATTR_POWER_NOW = 'power_now'
+ATTR_SERIAL_NUMBER = 'serial_number'
+ATTR_STATUS = 'status'
+ATTR_VOLTAGE_MIN_DESIGN = 'voltage_min_design'
+ATTR_VOLTAGE_NOW = 'voltage_now'
+
+CONF_BATTERY = 'battery'
+
+DEFAULT_BATTERY = 1
+DEFAULT_NAME = 'Battery'
+DEFAULT_PATH = '/sys/class/power_supply'
+
+ICON = 'mdi:battery'
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Optional(CONF_BATTERY, default=DEFAULT_BATTERY): cv.positive_int,
+    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
+})
+
+
+def setup_platform(hass, config, add_devices, discovery_info=None):
+    """Setup the Linux Battery sensor."""
+    name = config.get(CONF_NAME)
+    battery_id = config.get(CONF_BATTERY)
+
+    try:
+        os.listdir(os.path.join(DEFAULT_PATH, 'BAT{}'.format(battery_id)))
+    except FileNotFoundError:
+        _LOGGER.error("No battery found")
+        return False
+
+    add_devices([LinuxBatterySensor(name, battery_id)])
+
+
+# pylint: disable=too-few-public-methods
+class LinuxBatterySensor(Entity):
+    """Representation of a Linux Battery sensor."""
+
+    def __init__(self, name, battery_id):
+        """Initialize the battery sensor."""
+        import batinfo
+        self._battery = batinfo.Batteries()
+
+        self._name = name
+        self._battery_stat = None
+        self._battery_id = battery_id - 1
+        self._unit_of_measurement = '%'
+        self.update()
+
+    @property
+    def name(self):
+        """Return the name of the sensor."""
+        return self._name
+
+    @property
+    def state(self):
+        """Return the state of the sensor."""
+        return self._battery_stat.capacity
+
+    @property
+    def unit_of_measurement(self):
+        """Return the unit the value is expressed in."""
+        return self._unit_of_measurement
+
+    @property
+    def icon(self):
+        """Return the icon to use in the frontend, if any."""
+        return ICON
+
+    @property
+    def state_attributes(self):
+        """Return the state attributes of the sensor."""
+        return {
+            ATTR_NAME: self._battery_stat.name,
+            ATTR_PATH: self._battery_stat.path,
+            ATTR_ALARM: self._battery_stat.alarm,
+            ATTR_CAPACITY_LEVEL: self._battery_stat.capacity_level,
+            ATTR_CYCLE_COUNT: self._battery_stat.cycle_count,
+            ATTR_ENERGY_FULL: self._battery_stat.energy_full,
+            ATTR_ENERGY_FULL_DESIGN: self._battery_stat.energy_full_design,
+            ATTR_ENERGY_NOW: self._battery_stat.energy_now,
+            ATTR_MANUFACTURER: self._battery_stat.manufacturer,
+            ATTR_MODEL_NAME: self._battery_stat.model_name,
+            ATTR_POWER_NOW: self._battery_stat.power_now,
+            ATTR_SERIAL_NUMBER: self._battery_stat.serial_number,
+            ATTR_STATUS: self._battery_stat.status,
+            ATTR_VOLTAGE_MIN_DESIGN: self._battery_stat.voltage_min_design,
+            ATTR_VOLTAGE_NOW: self._battery_stat.voltage_now,
+        }
+
+    def update(self):
+        """Get the latest data and updates the states."""
+        self._battery.update()
+        self._battery_stat = self._battery.stat[self._battery_id]

requirements_all.txt

@@ -34,6 +34,9 @@ apcaccess==0.0.4
 # homeassistant.components.sun
 astral==1.2
 
+# homeassistant.components.sensor.linux_battery
+batinfo==0.3
+
 # homeassistant.components.light.blinksticklight
 blinkstick==1.1.8