Show battery voltage to 2 decimal places

Add optional 'precision' register field -> suggested_display_precision, and
set battery voltage (0.01 V resolution) to 2 decimals.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Developer089

custom_components/deye_modbus/__init__.py

@@ -28,7 +28,7 @@
 _REGISTER_FIELDS = {
     "name", "unique_id", "register_type", "address", "count", "scale", "offset",
     "unit_of_measurement", "device_class", "state_class", "signed", "word_order",
-    "options", "mask", "icon", "enabled_default",
+    "options", "mask", "icon", "enabled_default", "precision",
 }
 
 

custom_components/deye_modbus/coordinator.py

@@ -45,6 +45,7 @@ class RegisterDef:
     mask: int | None = None                  # bitmask applied to raw before sign/scale
     icon: str | None = None
     enabled_default: bool = True             # entity_registry_enabled_default
+    precision: int | None = None             # suggested_display_precision (decimals)
 
 
 class DeyeModbusCoordinator(DataUpdateCoordinator[dict[str, Any]]):

custom_components/deye_modbus/maps/sun_3ph_hybrid.yaml

@@ -175,6 +175,7 @@ sensors:
     address: 587
     count: 1
     scale: 0.01
+    precision: 2
     unit_of_measurement: V
     device_class: voltage
     state_class: measurement

custom_components/deye_modbus/sensor.py

@@ -40,6 +40,8 @@ def __init__(self, coordinator: DeyeModbusCoordinator, entry: ConfigEntry, reg:
         self._attr_device_info = build_device_info(entry)
         self._attr_native_unit_of_measurement = reg.unit_of_measurement
         self._attr_entity_registry_enabled_default = bool(reg.enabled_default)
+        if reg.precision is not None:
+            self._attr_suggested_display_precision = int(reg.precision)
         if reg.icon:
             self._attr_icon = reg.icon
         if reg.device_class: