Merge pull request #284 from MakeMeASandwich/dev

Add support for Adafruit temperature/humidity sensors

.coveragerc

@@ -57,6 +57,7 @@ omit =
     homeassistant/components/notify/syslog.py
     homeassistant/components/notify/xmpp.py
     homeassistant/components/sensor/bitcoin.py
+    homeassistant/components/sensor/dht.py
     homeassistant/components/sensor/efergy.py
     homeassistant/components/sensor/forecast.py
     homeassistant/components/sensor/mysensors.py

homeassistant/components/sensor/dht.py

@@ -0,0 +1,163 @@
+"""
+homeassistant.components.sensor.dht
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Adafruit DHT temperature and humidity sensor.
+You need a Python3 compatible version of the Adafruit_Python_DHT library
+(e.g. https://github.com/mala-zaba/Adafruit_Python_DHT,
+also see requirements.txt).
+As this requires access to the GPIO, you will need to run home-assistant
+as root.
+
+Configuration:
+
+To use the Adafruit DHT sensor you will need to
+add something like the following to your config/configuration.yaml:
+
+sensor:
+  platform: dht
+  sensor: DHT22
+  pin: 23
+  monitored_conditions:
+    - temperature
+    - humidity
+
+Variables:
+
+sensor
+*Required
+The sensor type, DHT11, DHT22 or AM2302
+
+pin
+*Required
+The pin the sensor is connected to, something like
+'P8_11' for Beaglebone, '23' for Raspberry Pi
+
+monitored_conditions
+*Optional
+Conditions to monitor. Available conditions are temperature and humidity.
+"""
+import logging
+from datetime import timedelta
+
+from homeassistant.util import Throttle
+from homeassistant.const import TEMP_FAHRENHEIT
+from homeassistant.helpers.entity import Entity
+
+# update this requirement to upstream as soon as it supports python3
+REQUIREMENTS = ['git+git://github.com/mala-zaba/Adafruit_Python_DHT']
+_LOGGER = logging.getLogger(__name__)
+SENSOR_TYPES = {
+    'temperature': ['Temperature', ''],
+    'humidity': ['Humidity', '%']
+}
+# 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):
+    """ Get the DHT sensor. """
+
+    try:
+        import Adafruit_DHT
+
+    except ImportError:
+        _LOGGER.exception(
+            "Unable to import Adafruit_DHT. "
+            "Did you maybe not install the 'Adafruit_DHT' package?")
+
+        return False
+
+    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 = []
+    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))
+    except KeyError:
+        pass
+
+    add_devices(dev)
+
+
+# pylint: disable=too-few-public-methods
+class DHTSensor(Entity):
+
+    """ Implements an DHT sensor. """
+
+    def __init__(self, dht_client, sensor_type, temp_unit):
+        self.client_name = 'DHT sensor'
+        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 '{} {}'.format(self.client_name, self._name)
+
+    @property
+    def state(self):
+        """ Returns the state of the device. """
+        return self._state
+
+    @property
+    def unit_of_measurement(self):
+        """ Unit of measurement of this entity, if any. """
+        return self._unit_of_measurement
+
+    def update(self):
+        """ Gets 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):
+
+    """ Gets the latest data from the DHT sensor. """
+
+    def __init__(self, adafruit_dht, sensor, pin):
+        self.adafruit_dht = adafruit_dht
+        self.sensor = sensor
+        self.pin = pin
+        self.data = dict()
+
+    @Throttle(MIN_TIME_BETWEEN_UPDATES)
+    def update(self):
+        """ Gets 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

requirements.txt

@@ -105,6 +105,10 @@ https://github.com/rkabadi/pyedimax/archive/master.zip
 # RPI-GPIO platform (*.rpi_gpio)
 RPi.GPIO >=0.5.11
 
+# Adafruit temperature/humidity sensor
+# uncomment on a Raspberry Pi / Beaglebone
+#git+git://github.com/mala-zaba/Adafruit_Python_DHT
+
 # PAHO MQTT Binding (mqtt)
 paho-mqtt>=1.1