core/homeassistant/components/sensor/modbus.py

107 lines
3.4 KiB
Python

"""
Support for Modbus Register sensors.
For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/sensor.modbus/
"""
import logging
import voluptuous as vol
import homeassistant.components.modbus as modbus
from homeassistant.const import (
CONF_NAME, CONF_OFFSET, CONF_UNIT_OF_MEASUREMENT)
from homeassistant.helpers.entity import Entity
from homeassistant.helpers import config_validation as cv
from homeassistant.components.sensor import PLATFORM_SCHEMA
_LOGGER = logging.getLogger(__name__)
DEPENDENCIES = ['modbus']
CONF_COUNT = "count"
CONF_PRECISION = "precision"
CONF_REGISTER = "register"
CONF_REGISTERS = "registers"
CONF_SCALE = "scale"
CONF_SLAVE = "slave"
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_OFFSET, default=0): vol.Coerce(float),
vol.Optional(CONF_PRECISION, default=0): cv.positive_int,
vol.Optional(CONF_SCALE, default=1): vol.Coerce(float),
vol.Optional(CONF_SLAVE): cv.positive_int,
vol.Optional(CONF_UNIT_OF_MEASUREMENT): cv.string
}]
})
def setup_platform(hass, config, add_devices, discovery_info=None):
"""Setup Modbus sensors."""
sensors = []
for register in config.get(CONF_REGISTERS):
sensors.append(ModbusRegisterSensor(
register.get(CONF_NAME),
register.get(CONF_SLAVE),
register.get(CONF_REGISTER),
register.get(CONF_UNIT_OF_MEASUREMENT),
register.get(CONF_COUNT),
register.get(CONF_SCALE),
register.get(CONF_OFFSET),
register.get(CONF_PRECISION)))
add_devices(sensors)
class ModbusRegisterSensor(Entity):
"""Modbus resgister sensor."""
# pylint: disable=too-many-instance-attributes, too-many-arguments
def __init__(self, name, slave, register, unit_of_measurement, count,
scale, offset, precision):
"""Initialize the modbus register sensor."""
self._name = name
self._slave = int(slave) if slave else None
self._register = int(register)
self._unit_of_measurement = unit_of_measurement
self._count = int(count)
self._scale = scale
self._offset = offset
self._precision = precision
self._value = None
@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
def update(self):
"""Update the state of the sensor."""
result = modbus.HUB.read_holding_registers(
self._slave,
self._register,
self._count)
val = 0
if not result:
_LOGGER.error(
'No response from modbus slave %s register %s',
self._slave,
self._register)
return
for i, res in enumerate(result.registers):
val += res * (2**(i*16))
self._value = format(
self._scale * val + self._offset,
".{}f".format(self._precision))