Fix battery level calculation for Nest Protect by adding support for battery voltage conversions

config/configuration.yaml

@@ -1,7 +1,7 @@
 default_config:
 
 logger:
-  default: info
+  default: error
   logs:
     custom_components.nest_protect: debug
 

custom_components/nest_protect/__init__.py

@@ -74,8 +74,10 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry):
     client = NestClient(session=session, environment=NEST_ENVIRONMENTS[account_type])
 
     try:
+        # Using user-retrieved cookies for authentication
         if issue_token and cookies:
             auth = await client.get_access_token_from_cookies(issue_token, cookies)
+        # Using refresh_token from legacy authentication method
         elif refresh_token:
             auth = await client.get_access_token_from_refresh_token(refresh_token)
         else:

custom_components/nest_protect/entity.py

@@ -1,9 +1,6 @@
 """Entity class for Nest Protect."""
 from __future__ import annotations
 
-from enum import unique
-
-from homeassistant.backports.enum import StrEnum
 from homeassistant.core import callback
 from homeassistant.helpers import device_registry as dr
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
@@ -118,11 +115,3 @@ def __init__(
         super().__init__(bucket, description, areas, client)
         self._attr_name = f"{super().name} {self.entity_description.name}"
         self._attr_unique_id = f"{super().unique_id}-{self.entity_description.key}"
-
-
-# Used by state translations for sensor and select entities
-@unique
-class NestProtectDeviceClass(StrEnum):
-    """Device class for Nest Protect specific devices."""
-
-    NIGHT_LIGHT_BRIGHTNESS = "nest_protect__night_light_brightness"

custom_components/nest_protect/pynest/enums.py

@@ -0,0 +1,22 @@
+"""Enums for Nest Protect."""
+from enum import StrEnum, unique
+import logging
+
+_LOGGER = logging.getLogger(__name__)
+
+
+@unique
+class BucketType(StrEnum):
+    """Bucket types."""
+
+    KRYPTONITE = "kryptonite"
+    TOPAZ = "topaz"
+    WHERE = "where"
+
+    UNKNOWN = "unknown"
+
+    @classmethod
+    def _missing_(cls, value):  # type: ignore
+        _LOGGER.warning(f"Unsupported value {value} has been returned for {cls}")
+
+        return cls.UNKNOWN

custom_components/nest_protect/pynest/models.py

@@ -5,6 +5,8 @@
 import datetime
 from typing import Any
 
+from .enums import BucketType
+
 
 @dataclass
 class NestLimits:
@@ -72,6 +74,11 @@ class Bucket:
     object_revision: str
     object_timestamp: str
     value: Any
+    type: str = ""
+
+    def __post_init__(self):
+        """Set the expiry date during post init."""
+        self.type = BucketType(self.object_key.split(".")[0])
 
 
 @dataclass

custom_components/nest_protect/sensor.py

@@ -10,7 +10,6 @@
     SensorDeviceClass,
     SensorEntity,
     SensorEntityDescription,
-    SensorStateClass,
 )
 from homeassistant.const import PERCENTAGE, TEMP_CELSIUS
 from homeassistant.helpers.entity import EntityCategory
@@ -19,23 +18,74 @@
 from . import HomeAssistantNestProtectData
 from .const import DOMAIN
 from .entity import NestDescriptiveEntity
+from .pynest.enums import BucketType
+
+
+def milli_volt_to_percentage(state: int):
+    """
+    Convert battery level in mV to a percentage.
+
+    The battery life percentage in devices is estimated using slopes from the L91 battery's datasheet.
+    This is a rough estimation, and the battery life percentage is not linear.
+
+    Tests on various devices have shown accurate results.
+    """
+    if 3000 < state <= 6000:
+        if 4950 < state <= 6000:
+            slope = 0.001816609
+            yint = -8.548096886
+        elif 4800 < state <= 4950:
+            slope = 0.000291667
+            yint = -0.991176471
+        elif 4500 < state <= 4800:
+            slope = 0.001077342
+            yint = -4.730392157
+        else:
+            slope = 0.000434641
+            yint = -1.825490196
+
+        return max(0, min(100, round(((slope * state) + yint) * 100)))
+
+    return None
 
 
 @dataclass
 class NestProtectSensorDescription(SensorEntityDescription):
     """Class to describe an Nest Protect sensor."""
 
     value_fn: Callable[[Any], StateType] | None = None
+    bucket_type: BucketType | None = (
+        None  # used to filter out sensors that are not supported by the device
+    )
 
 
-SENSOR_DESCRIPTIONS: list[SensorEntityDescription] = [
+SENSOR_DESCRIPTIONS: list[NestProtectSensorDescription] = [
+    NestProtectSensorDescription(
+        key="battery_level",
+        name="Battery Level",
+        device_class=SensorDeviceClass.BATTERY,
+        native_unit_of_measurement=PERCENTAGE,
+        entity_category=EntityCategory.DIAGNOSTIC,
+        bucket_type=BucketType.KRYPTONITE,
+    ),
+    # TODO Due to duplicate keys, this sensor is not available yet
+    # NestProtectSensorDescription(
+    #     key="battery_level",
+    #     name="Battery Voltage",
+    #     value_fn=lambda state: round(state / 1000, 3),
+    #     device_class=SensorDeviceClass.BATTERY,
+    #     native_unit_of_measurement=UnitOfElectricPotential.VOLT,
+    #     entity_category=EntityCategory.DIAGNOSTIC,
+    #     bucket_type=BucketType.TOPAZ,
+    # ),
     NestProtectSensorDescription(
         key="battery_level",
         name="Battery Level",
-        value_fn=lambda state: state if state <= 100 else None,
+        value_fn=lambda state: milli_volt_to_percentage(state),
         device_class=SensorDeviceClass.BATTERY,
         native_unit_of_measurement=PERCENTAGE,
         entity_category=EntityCategory.DIAGNOSTIC,
+        bucket_type=BucketType.TOPAZ,
     ),
     NestProtectSensorDescription(
         name="Replace By",
@@ -50,7 +100,6 @@ class NestProtectSensorDescription(SensorEntityDescription):
         value_fn=lambda state: round(state, 2),
         device_class=SensorDeviceClass.TEMPERATURE,
         native_unit_of_measurement=TEMP_CELSIUS,
-        state_class=SensorStateClass.MEASUREMENT,
     ),
     # TODO Add Color Status (gray, green, yellow, red)
     # TODO Smoke Status (OK, Warning, Emergency)
@@ -64,13 +113,16 @@ async def async_setup_entry(hass, entry, async_add_devices):
     data: HomeAssistantNestProtectData = hass.data[DOMAIN][entry.entry_id]
     entities: list[NestProtectSensor] = []
 
-    SUPPORTED_KEYS = {
+    SUPPORTED_KEYS: dict[str, NestProtectSensorDescription] = {
         description.key: description for description in SENSOR_DESCRIPTIONS
     }
 
     for device in data.devices.values():
         for key in device.value:
             if description := SUPPORTED_KEYS.get(key):
+                if description.bucket_type and device.type != description.bucket_type:
+                    continue
+
                 entities.append(
                     NestProtectSensor(device, description, data.areas, data.client)
                 )

requirements_dev.txt

@@ -1,2 +1,2 @@
-homeassistant==2023.12.0
+homeassistant==2023.12.3
 pre-commit

requirements_test.txt

@@ -2,5 +2,5 @@
 
 pytest==7.4.3
 pytest-socket==0.6.0
-pytest-homeassistant-custom-component==0.13.82 # 2023.12.0
+pytest-homeassistant-custom-component==0.13.85 # 2023.12.3
 pytest-timeout==2.1.0