"""Support for Modbus Register sensors."""
from __future__ import annotations
import logging
import struct
from typing import Any
from pymodbus.exceptions import ConnectionException, ModbusException
from pymodbus.pdu import ExceptionResponse
import voluptuous as vol
from homeassistant.components.sensor import DEVICE_CLASSES_SCHEMA, PLATFORM_SCHEMA
from homeassistant.const import (
CONF_DEVICE_CLASS,
CONF_NAME,
CONF_OFFSET,
CONF_SLAVE,
CONF_STRUCTURE,
CONF_UNIT_OF_MEASUREMENT,
)
from homeassistant.helpers import config_validation as cv
from homeassistant.helpers.restore_state import RestoreEntity
from .const import (
CALL_TYPE_REGISTER_HOLDING,
CALL_TYPE_REGISTER_INPUT,
CONF_COUNT,
CONF_DATA_TYPE,
CONF_HUB,
CONF_PRECISION,
CONF_REGISTER,
CONF_REGISTER_TYPE,
CONF_REGISTERS,
CONF_REVERSE_ORDER,
CONF_SCALE,
DATA_TYPE_CUSTOM,
DATA_TYPE_FLOAT,
DATA_TYPE_INT,
DATA_TYPE_STRING,
DATA_TYPE_UINT,
DEFAULT_HUB,
DEFAULT_STRUCT_FORMAT,
MODBUS_DOMAIN,
)
_LOGGER = logging.getLogger(__name__)
def number(value: Any) -> int | float:
"""Coerce a value to number without losing precision."""
if isinstance(value, int):
return value
if isinstance(value, str):
try:
value = int(value)
return value
except (TypeError, ValueError):
pass
try:
value = float(value)
return value
except (TypeError, ValueError) as err:
raise vol.Invalid(f"invalid number {value}") from err
PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
{
vol.Required(CONF_REGISTERS): [
{
vol.Required(CONF_NAME): cv.string,
vol.Required(CONF_REGISTER): cv.positive_int,
vol.Optional(CONF_COUNT, default=1): cv.positive_int,
vol.Optional(CONF_DATA_TYPE, default=DATA_TYPE_INT): vol.In(
[
DATA_TYPE_INT,
DATA_TYPE_UINT,
DATA_TYPE_FLOAT,
DATA_TYPE_STRING,
DATA_TYPE_CUSTOM,
]
),
vol.Optional(CONF_DEVICE_CLASS): DEVICE_CLASSES_SCHEMA,
vol.Optional(CONF_HUB, default=DEFAULT_HUB): cv.string,
vol.Optional(CONF_OFFSET, default=0): number,
vol.Optional(CONF_PRECISION, default=0): cv.positive_int,
vol.Optional(
CONF_REGISTER_TYPE, default=CALL_TYPE_REGISTER_HOLDING
): vol.In([CALL_TYPE_REGISTER_HOLDING, CALL_TYPE_REGISTER_INPUT]),
vol.Optional(CONF_REVERSE_ORDER, default=False): cv.boolean,
vol.Optional(CONF_SCALE, default=1): number,
vol.Optional(CONF_SLAVE): cv.positive_int,
vol.Optional(CONF_STRUCTURE): cv.string,
vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string,
}
]
}
)
def setup_platform(hass, config, add_entities, discovery_info=None):
"""Set up the Modbus sensors."""
sensors = []
for register in config[CONF_REGISTERS]:
if register[CONF_DATA_TYPE] == DATA_TYPE_STRING:
structure = str(register[CONF_COUNT] * 2) + "s"
elif register[CONF_DATA_TYPE] != DATA_TYPE_CUSTOM:
try:
structure = f">{DEFAULT_STRUCT_FORMAT[register[CONF_DATA_TYPE]][register[CONF_COUNT]]}"
except KeyError:
_LOGGER.error(
"Unable to detect data type for %s sensor, try a custom type",
register[CONF_NAME],
)
continue
else:
structure = register.get(CONF_STRUCTURE)
try:
size = struct.calcsize(structure)
except struct.error as err:
_LOGGER.error("Error in sensor %s structure: %s", register[CONF_NAME], err)
continue
if register[CONF_COUNT] * 2 != size:
_LOGGER.error(
"Structure size (%d bytes) mismatch registers count (%d words)",
size,
register[CONF_COUNT],
)
continue
hub_name = register[CONF_HUB]
hub = hass.data[MODBUS_DOMAIN][hub_name]
sensors.append(
ModbusRegisterSensor(
hub,
register[CONF_NAME],
register.get(CONF_SLAVE),
register[CONF_REGISTER],
register[CONF_REGISTER_TYPE],
register.get(CONF_UNIT_OF_MEASUREMENT),
register[CONF_COUNT],
register[CONF_REVERSE_ORDER],
register[CONF_SCALE],
register[CONF_OFFSET],
structure,
register[CONF_PRECISION],
register[CONF_DATA_TYPE],
register.get(CONF_DEVICE_CLASS),
)
)
if not sensors:
return False
add_entities(sensors)
class ModbusRegisterSensor(RestoreEntity):
"""Modbus register sensor."""
def __init__(
self,
hub,
name,
slave,
register,
register_type,
unit_of_measurement,
count,
reverse_order,
scale,
offset,
structure,
precision,
data_type,
device_class,
):
"""Initialize the modbus register sensor."""
self._hub = hub
self._name = name
self._slave = int(slave) if slave else None
self._register = int(register)
self._register_type = register_type
self._unit_of_measurement = unit_of_measurement
self._count = int(count)
self._reverse_order = reverse_order
self._scale = scale
self._offset = offset
self._precision = precision
self._structure = structure
self._data_type = data_type
self._device_class = device_class
self._value = None
self._available = True
async def async_added_to_hass(self):
"""Handle entity which will be added."""
state = await self.async_get_last_state()
if not state:
return
self._value = state.state
@property
def state(self):
"""Return the state of the sensor."""
return self._value
@property
def name(self):
"""Return the name of the sensor."""
return self._name
@property
def unit_of_measurement(self):
"""Return the unit of measurement."""
return self._unit_of_measurement
@property
def device_class(self) -> str | None:
"""Return the device class of the sensor."""
return self._device_class
@property
def available(self) -> bool:
"""Return True if entity is available."""
return self._available
def update(self):
"""Update the state of the sensor."""
try:
if self._register_type == CALL_TYPE_REGISTER_INPUT:
result = self._hub.read_input_registers(
self._slave, self._register, self._count
)
else:
result = self._hub.read_holding_registers(
self._slave, self._register, self._count
)
except ConnectionException:
self._available = False
return
if isinstance(result, (ModbusException, ExceptionResponse)):
self._available = False
return
registers = result.registers
if self._reverse_order:
registers.reverse()
byte_string = b"".join([x.to_bytes(2, byteorder="big") for x in registers])
if self._data_type == DATA_TYPE_STRING:
self._value = byte_string.decode()
else:
val = struct.unpack(self._structure, byte_string)
# Issue: https://github.com/home-assistant/core/issues/41944
# If unpack() returns a tuple greater than 1, don't try to process the value.
# Instead, return the values of unpack(...) separated by commas.
if len(val) > 1:
self._value = ",".join(map(str, val))
else:
val = val[0]
# Apply scale and precision to floats and ints
if isinstance(val, (float, int)):
val = self._scale * val + self._offset
# We could convert int to float, and the code would still work; however
# we lose some precision, and unit tests will fail. Therefore, we do
# the conversion only when it's absolutely necessary.
if isinstance(val, int) and self._precision == 0:
self._value = str(val)
else:
self._value = f"{float(val):.{self._precision}f}"
else:
# Don't process remaining datatypes (bytes and booleans)
self._value = str(val)
self._available = True