core/homeassistant/components/sensor/dht.py

130 lines
4.0 KiB
Python

"""
Support for Adafruit DHT temperature and humidity sensor.
For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/sensor.dht/
"""
import logging
from datetime import timedelta
from homeassistant.const import TEMP_FAHRENHEIT
from homeassistant.helpers.entity import Entity
from homeassistant.util import Throttle
# Update this requirement to upstream as soon as it supports Python 3.
REQUIREMENTS = ['http://github.com/mala-zaba/Adafruit_Python_DHT/archive/'
'4101340de8d2457dd194bca1e8d11cbfc237e919.zip'
'#Adafruit_DHT==1.1.0']
_LOGGER = logging.getLogger(__name__)
SENSOR_TYPES = {
'temperature': ['Temperature', None],
'humidity': ['Humidity', '%']
}
DEFAULT_NAME = "DHT Sensor"
# Return cached results if last scan was less then this time ago
# DHT11 is able to deliver data once per second, DHT22 once every two
MIN_TIME_BETWEEN_UPDATES = timedelta(seconds=30)
def setup_platform(hass, config, add_devices, discovery_info=None):
"""Setup the DHT sensor."""
# pylint: disable=import-error
import Adafruit_DHT
SENSOR_TYPES['temperature'][1] = hass.config.temperature_unit
unit = hass.config.temperature_unit
available_sensors = {
"DHT11": Adafruit_DHT.DHT11,
"DHT22": Adafruit_DHT.DHT22,
"AM2302": Adafruit_DHT.AM2302
}
sensor = available_sensors[config['sensor']]
pin = config['pin']
if not sensor or not pin:
_LOGGER.error(
"Config error "
"Please check your settings for DHT, sensor not supported.")
return None
data = DHTClient(Adafruit_DHT, sensor, pin)
dev = []
name = config.get('name', DEFAULT_NAME)
try:
for variable in config['monitored_conditions']:
if variable not in SENSOR_TYPES:
_LOGGER.error('Sensor type: "%s" does not exist', variable)
else:
dev.append(DHTSensor(data, variable, unit, name))
except KeyError:
pass
add_devices(dev)
# pylint: disable=too-few-public-methods
class DHTSensor(Entity):
"""Implementation of the DHT sensor."""
def __init__(self, dht_client, sensor_type, temp_unit, name):
"""Initialize the sensor."""
self.client_name = name
self._name = SENSOR_TYPES[sensor_type][0]
self.dht_client = dht_client
self.temp_unit = temp_unit
self.type = sensor_type
self._state = None
self._unit_of_measurement = SENSOR_TYPES[sensor_type][1]
self.update()
@property
def name(self):
"""Return the name of the sensor."""
return '{} {}'.format(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 this entity, if any."""
return self._unit_of_measurement
def update(self):
"""Get the latest data from the DHT and updates the states."""
self.dht_client.update()
data = self.dht_client.data
if self.type == 'temperature':
self._state = round(data['temperature'], 1)
if self.temp_unit == TEMP_FAHRENHEIT:
self._state = round(data['temperature'] * 1.8 + 32, 1)
elif self.type == 'humidity':
self._state = round(data['humidity'], 1)
class DHTClient(object):
"""Get the latest data from the DHT sensor."""
def __init__(self, adafruit_dht, sensor, pin):
"""Initialize the sensor."""
self.adafruit_dht = adafruit_dht
self.sensor = sensor
self.pin = pin
self.data = dict()
@Throttle(MIN_TIME_BETWEEN_UPDATES)
def update(self):
"""Get the latest data the DHT sensor."""
humidity, temperature = self.adafruit_dht.read_retry(self.sensor,
self.pin)
if temperature:
self.data['temperature'] = temperature
if humidity:
self.data['humidity'] = humidity