"""Support for BME680 Sensor over SMBus."""
import logging
import threading
from time import sleep, time
from smbus import SMBus # pylint: disable=import-error
import bme680 # pylint: disable=import-error
import voluptuous as vol
from homeassistant.components.sensor import PLATFORM_SCHEMA
from homeassistant.const import CONF_MONITORED_CONDITIONS, CONF_NAME, TEMP_FAHRENHEIT
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity
from homeassistant.util.temperature import celsius_to_fahrenheit
_LOGGER = logging.getLogger(__name__)
CONF_I2C_ADDRESS = "i2c_address"
CONF_I2C_BUS = "i2c_bus"
CONF_OVERSAMPLING_TEMP = "oversampling_temperature"
CONF_OVERSAMPLING_PRES = "oversampling_pressure"
CONF_OVERSAMPLING_HUM = "oversampling_humidity"
CONF_FILTER_SIZE = "filter_size"
CONF_GAS_HEATER_TEMP = "gas_heater_temperature"
CONF_GAS_HEATER_DURATION = "gas_heater_duration"
CONF_AQ_BURN_IN_TIME = "aq_burn_in_time"
CONF_AQ_HUM_BASELINE = "aq_humidity_baseline"
CONF_AQ_HUM_WEIGHTING = "aq_humidity_bias"
CONF_TEMP_OFFSET = "temp_offset"
DEFAULT_NAME = "BME680 Sensor"
DEFAULT_I2C_ADDRESS = 0x77
DEFAULT_I2C_BUS = 1
DEFAULT_OVERSAMPLING_TEMP = 8 # Temperature oversampling x 8
DEFAULT_OVERSAMPLING_PRES = 4 # Pressure oversampling x 4
DEFAULT_OVERSAMPLING_HUM = 2 # Humidity oversampling x 2
DEFAULT_FILTER_SIZE = 3 # IIR Filter Size
DEFAULT_GAS_HEATER_TEMP = 320 # Temperature in celsius 200 - 400
DEFAULT_GAS_HEATER_DURATION = 150 # Heater duration in ms 1 - 4032
DEFAULT_AQ_BURN_IN_TIME = 300 # 300 second burn in time for AQ gas measurement
DEFAULT_AQ_HUM_BASELINE = 40 # 40%, an optimal indoor humidity.
DEFAULT_AQ_HUM_WEIGHTING = 25 # 25% Weighting of humidity to gas in AQ score
DEFAULT_TEMP_OFFSET = 0 # No calibration out of the box.
SENSOR_TEMP = "temperature"
SENSOR_HUMID = "humidity"
SENSOR_PRESS = "pressure"
SENSOR_GAS = "gas"
SENSOR_AQ = "airquality"
SENSOR_TYPES = {
SENSOR_TEMP: ["Temperature", None],
SENSOR_HUMID: ["Humidity", "%"],
SENSOR_PRESS: ["Pressure", "mb"],
SENSOR_GAS: ["Gas Resistance", "Ohms"],
SENSOR_AQ: ["Air Quality", "%"],
}
DEFAULT_MONITORED = [SENSOR_TEMP, SENSOR_HUMID, SENSOR_PRESS, SENSOR_AQ]
OVERSAMPLING_VALUES = set([0, 1, 2, 4, 8, 16])
FILTER_VALUES = set([0, 1, 3, 7, 15, 31, 63, 127])
PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
{
vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
vol.Optional(CONF_I2C_ADDRESS, default=DEFAULT_I2C_ADDRESS): cv.positive_int,
vol.Optional(CONF_MONITORED_CONDITIONS, default=DEFAULT_MONITORED): vol.All(
cv.ensure_list, [vol.In(SENSOR_TYPES)]
),
vol.Optional(CONF_I2C_BUS, default=DEFAULT_I2C_BUS): cv.positive_int,
vol.Optional(
CONF_OVERSAMPLING_TEMP, default=DEFAULT_OVERSAMPLING_TEMP
): vol.All(vol.Coerce(int), vol.In(OVERSAMPLING_VALUES)),
vol.Optional(
CONF_OVERSAMPLING_PRES, default=DEFAULT_OVERSAMPLING_PRES
): vol.All(vol.Coerce(int), vol.In(OVERSAMPLING_VALUES)),
vol.Optional(CONF_OVERSAMPLING_HUM, default=DEFAULT_OVERSAMPLING_HUM): vol.All(
vol.Coerce(int), vol.In(OVERSAMPLING_VALUES)
),
vol.Optional(CONF_FILTER_SIZE, default=DEFAULT_FILTER_SIZE): vol.All(
vol.Coerce(int), vol.In(FILTER_VALUES)
),
vol.Optional(CONF_GAS_HEATER_TEMP, default=DEFAULT_GAS_HEATER_TEMP): vol.All(
vol.Coerce(int), vol.Range(200, 400)
),
vol.Optional(
CONF_GAS_HEATER_DURATION, default=DEFAULT_GAS_HEATER_DURATION
): vol.All(vol.Coerce(int), vol.Range(1, 4032)),
vol.Optional(
CONF_AQ_BURN_IN_TIME, default=DEFAULT_AQ_BURN_IN_TIME
): cv.positive_int,
vol.Optional(CONF_AQ_HUM_BASELINE, default=DEFAULT_AQ_HUM_BASELINE): vol.All(
vol.Coerce(int), vol.Range(1, 100)
),
vol.Optional(CONF_AQ_HUM_WEIGHTING, default=DEFAULT_AQ_HUM_WEIGHTING): vol.All(
vol.Coerce(int), vol.Range(1, 100)
),
vol.Optional(CONF_TEMP_OFFSET, default=DEFAULT_TEMP_OFFSET): vol.All(
vol.Coerce(float), vol.Range(-100.0, 100.0)
),
}
)
async def async_setup_platform(hass, config, async_add_entities, discovery_info=None):
"""Set up the BME680 sensor."""
SENSOR_TYPES[SENSOR_TEMP][1] = hass.config.units.temperature_unit
name = config.get(CONF_NAME)
sensor_handler = await hass.async_add_job(_setup_bme680, config)
if sensor_handler is None:
return
dev = []
for variable in config[CONF_MONITORED_CONDITIONS]:
dev.append(
BME680Sensor(sensor_handler, variable, SENSOR_TYPES[variable][1], name)
)
async_add_entities(dev)
return
def _setup_bme680(config):
"""Set up and configure the BME680 sensor."""
sensor_handler = None
sensor = None
try:
# pylint: disable=no-member
i2c_address = config.get(CONF_I2C_ADDRESS)
bus = SMBus(config.get(CONF_I2C_BUS))
sensor = bme680.BME680(i2c_address, bus)
# Configure Oversampling
os_lookup = {
0: bme680.OS_NONE,
1: bme680.OS_1X,
2: bme680.OS_2X,
4: bme680.OS_4X,
8: bme680.OS_8X,
16: bme680.OS_16X,
}
sensor.set_temperature_oversample(os_lookup[config.get(CONF_OVERSAMPLING_TEMP)])
sensor.set_temp_offset(config.get(CONF_TEMP_OFFSET))
sensor.set_humidity_oversample(os_lookup[config.get(CONF_OVERSAMPLING_HUM)])
sensor.set_pressure_oversample(os_lookup[config.get(CONF_OVERSAMPLING_PRES)])
# Configure IIR Filter
filter_lookup = {
0: bme680.FILTER_SIZE_0,
1: bme680.FILTER_SIZE_1,
3: bme680.FILTER_SIZE_3,
7: bme680.FILTER_SIZE_7,
15: bme680.FILTER_SIZE_15,
31: bme680.FILTER_SIZE_31,
63: bme680.FILTER_SIZE_63,
127: bme680.FILTER_SIZE_127,
}
sensor.set_filter(filter_lookup[config.get(CONF_FILTER_SIZE)])
# Configure the Gas Heater
if (
SENSOR_GAS in config[CONF_MONITORED_CONDITIONS]
or SENSOR_AQ in config[CONF_MONITORED_CONDITIONS]
):
sensor.set_gas_status(bme680.ENABLE_GAS_MEAS)
sensor.set_gas_heater_duration(config[CONF_GAS_HEATER_DURATION])
sensor.set_gas_heater_temperature(config[CONF_GAS_HEATER_TEMP])
sensor.select_gas_heater_profile(0)
else:
sensor.set_gas_status(bme680.DISABLE_GAS_MEAS)
except (RuntimeError, OSError):
_LOGGER.error("BME680 sensor not detected at 0x%02x", i2c_address)
return None
sensor_handler = BME680Handler(
sensor,
(
SENSOR_GAS in config[CONF_MONITORED_CONDITIONS]
or SENSOR_AQ in config[CONF_MONITORED_CONDITIONS]
),
config[CONF_AQ_BURN_IN_TIME],
config[CONF_AQ_HUM_BASELINE],
config[CONF_AQ_HUM_WEIGHTING],
)
sleep(0.5) # Wait for device to stabilize
if not sensor_handler.sensor_data.temperature:
_LOGGER.error("BME680 sensor failed to Initialize")
return None
return sensor_handler
class BME680Handler:
"""BME680 sensor working in i2C bus."""
class SensorData:
"""Sensor data representation."""
def __init__(self):
"""Initialize the sensor data object."""
self.temperature = None
self.humidity = None
self.pressure = None
self.gas_resistance = None
self.air_quality = None
def __init__(
self,
sensor,
gas_measurement=False,
burn_in_time=300,
hum_baseline=40,
hum_weighting=25,
):
"""Initialize the sensor handler."""
self.sensor_data = BME680Handler.SensorData()
self._sensor = sensor
self._gas_sensor_running = False
self._hum_baseline = hum_baseline
self._hum_weighting = hum_weighting
self._gas_baseline = None
if gas_measurement:
threading.Thread(
target=self._run_gas_sensor,
kwargs={"burn_in_time": burn_in_time},
name="BME680Handler_run_gas_sensor",
).start()
self.update(first_read=True)
def _run_gas_sensor(self, burn_in_time):
"""Calibrate the Air Quality Gas Baseline."""
if self._gas_sensor_running:
return
self._gas_sensor_running = True
# Pause to allow initial data read for device validation.
sleep(1)
start_time = time()
curr_time = time()
burn_in_data = []
_LOGGER.info(
"Beginning %d second gas sensor burn in for Air Quality", burn_in_time
)
while curr_time - start_time < burn_in_time:
curr_time = time()
if self._sensor.get_sensor_data() and self._sensor.data.heat_stable:
gas_resistance = self._sensor.data.gas_resistance
burn_in_data.append(gas_resistance)
self.sensor_data.gas_resistance = gas_resistance
_LOGGER.debug(
"AQ Gas Resistance Baseline reading %2f Ohms", gas_resistance
)
sleep(1)
_LOGGER.debug(
"AQ Gas Resistance Burn In Data (Size: %d): \n\t%s",
len(burn_in_data),
burn_in_data,
)
self._gas_baseline = sum(burn_in_data[-50:]) / 50.0
_LOGGER.info("Completed gas sensor burn in for Air Quality")
_LOGGER.info("AQ Gas Resistance Baseline: %f", self._gas_baseline)
while True:
if self._sensor.get_sensor_data() and self._sensor.data.heat_stable:
self.sensor_data.gas_resistance = self._sensor.data.gas_resistance
self.sensor_data.air_quality = self._calculate_aq_score()
sleep(1)
def update(self, first_read=False):
"""Read sensor data."""
if first_read:
# Attempt first read, it almost always fails first attempt
self._sensor.get_sensor_data()
if self._sensor.get_sensor_data():
self.sensor_data.temperature = self._sensor.data.temperature
self.sensor_data.humidity = self._sensor.data.humidity
self.sensor_data.pressure = self._sensor.data.pressure
def _calculate_aq_score(self):
"""Calculate the Air Quality Score."""
hum_baseline = self._hum_baseline
hum_weighting = self._hum_weighting
gas_baseline = self._gas_baseline
gas_resistance = self.sensor_data.gas_resistance
gas_offset = gas_baseline - gas_resistance
hum = self.sensor_data.humidity
hum_offset = hum - hum_baseline
# Calculate hum_score as the distance from the hum_baseline.
if hum_offset > 0:
hum_score = (
(100 - hum_baseline - hum_offset) / (100 - hum_baseline) * hum_weighting
)
else:
hum_score = (hum_baseline + hum_offset) / hum_baseline * hum_weighting
# Calculate gas_score as the distance from the gas_baseline.
if gas_offset > 0:
gas_score = (gas_resistance / gas_baseline) * (100 - hum_weighting)
else:
gas_score = 100 - hum_weighting
# Calculate air quality score.
return hum_score + gas_score
class BME680Sensor(Entity):
"""Implementation of the BME680 sensor."""
def __init__(self, bme680_client, sensor_type, temp_unit, name):
"""Initialize the sensor."""
self.client_name = name
self._name = SENSOR_TYPES[sensor_type][0]
self.bme680_client = bme680_client
self.temp_unit = temp_unit
self.type = sensor_type
self._state = None
self._unit_of_measurement = SENSOR_TYPES[sensor_type][1]
@property
def name(self):
"""Return the name of the sensor."""
return f"{self.client_name} {self._name}"
@property
def state(self):
"""Return the state of the sensor."""
return self._state
@property
def unit_of_measurement(self):
"""Return the unit of measurement of the sensor."""
return self._unit_of_measurement
async def async_update(self):
"""Get the latest data from the BME680 and update the states."""
await self.hass.async_add_job(self.bme680_client.update)
if self.type == SENSOR_TEMP:
temperature = round(self.bme680_client.sensor_data.temperature, 1)
if self.temp_unit == TEMP_FAHRENHEIT:
temperature = round(celsius_to_fahrenheit(temperature), 1)
self._state = temperature
elif self.type == SENSOR_HUMID:
self._state = round(self.bme680_client.sensor_data.humidity, 1)
elif self.type == SENSOR_PRESS:
self._state = round(self.bme680_client.sensor_data.pressure, 1)
elif self.type == SENSOR_GAS:
self._state = int(round(self.bme680_client.sensor_data.gas_resistance, 0))
elif self.type == SENSOR_AQ:
aq_score = self.bme680_client.sensor_data.air_quality
if aq_score is not None:
self._state = round(aq_score, 1)