Added DHT temperature/humidity sensor integration [closes #113]

docs/source/conf.py

@@ -259,6 +259,7 @@ autodoc_mock_imports = ['googlesamples.assistant.grpc.audio_helpers',
                         'gi.repository',
                         'twilio',
                         'pytz',
+                        'Adafruit_Python_DHT',
                         ]
 
 sys.path.insert(0, os.path.abspath('../..'))

platypush/backend/sensor/dht.py

@@ -0,0 +1,29 @@
+from platypush.backend.sensor import SensorBackend
+
+
+class SensorDhtBackend(SensorBackend):
+    """
+    Backend to poll a DHT11/DHT22/AM2302 temperature/humidity sensor.
+
+    Requires:
+
+        * ``Adafruit_Python_DHT`` (``pip install git+https://github.com/adafruit/Adafruit_Python_DHT.git``)
+        * The ``gpio.sensor.dht`` plugin configured and enabled.
+
+    """
+
+    def __init__(self, temperature: bool = True, humidity: bool = True, **kwargs):
+        """
+        :param temperature: Enable temperature sensor poll.
+        :param humidity: Enable humidity sensor poll.
+        """
+
+        enabled_sensors = {
+            'humidity': humidity,
+            'temperature': temperature,
+        }
+
+        super().__init__(plugin='gpio.sensor.dht', enabled_sensors=enabled_sensors, **kwargs)
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/gpio/sensor/dht.py

@@ -0,0 +1,93 @@
+from typing import Optional, Dict
+
+from platypush.plugins import action
+from platypush.plugins.gpio.sensor import GpioSensorPlugin
+
+
+class GpioSensorDhtPlugin(GpioSensorPlugin):
+    """
+    Plugin to interact with a DHT11/DHT22/AM2302 temperature/humidity sensor through GPIO.
+
+    Requires:
+
+        * ``Adafruit_Python_DHT`` (``pip install git+https://github.com/adafruit/Adafruit_Python_DHT.git``)
+
+    """
+
+    def __init__(self, sensor_type: str, pin: int, retries: int = 5,
+                 retry_seconds: int = 2, **kwargs):
+        """
+        :param sensor_type: Type of sensor to be used (supported types: DHT11, DHT22, AM2302).
+        :param pin: GPIO PIN where the sensor is connected.
+        :param retries: Number of retries in case of failed read (default: 5).
+        :param retry_seconds: Number of seconds to wait between retries (default: 2).
+        """
+        super().__init__(**kwargs)
+        self.sensor_type = self._get_sensor_type(sensor_type)
+        self.pin = pin
+        self.retries = retries
+        self.retry_seconds = retry_seconds
+
+    @staticmethod
+    def _get_sensor_type(sensor_type: str) -> int:
+        import Adafruit_DHT
+        sensor_type = sensor_type.upper()
+        assert hasattr(Adafruit_DHT, sensor_type), \
+            'Unknown sensor type: {}. Supported types: DHT11, DHT22, AM2302'.format(sensor_type)
+
+        return getattr(Adafruit_DHT, sensor_type)
+
+    @action
+    def read(self, sensor_type: Optional[str] = None, pin: Optional[int] = None,
+             retries: Optional[int] = None, retry_seconds: Optional[int] = None,
+             **kwargs) -> Dict[str, float]:
+        """
+        Read data from the sensor.
+
+        :param sensor_type: Default ``sensor_type`` override.
+        :param pin: Default ``pin`` override.
+        :param retries: Default ``retries`` override.
+        :param retry_seconds: Default ``retry_seconds`` override.
+        :return: A mapping with the measured temperature and humidity. Example:
+
+            .. code-block:: json
+
+                {
+                    "humidity": 30.0,
+                    "temperature": 25.5
+                }
+
+        """
+        import Adafruit_DHT
+        sensor_type = self._get_sensor_type(sensor_type) if sensor_type else self.sensor_type
+        pin = pin or self.pin
+        retries = retries or self.retries
+        retry_seconds = retry_seconds or self.retry_seconds
+        humidity, temperature = Adafruit_DHT.read_retry(sensor=sensor_type,
+            pin=pin, retries=retries, delay_seconds=retry_seconds)
+
+        return {
+            'humidity': humidity,
+            'temperature': temperature,
+        }
+
+    @action
+    def get_measurement(self) -> Dict[str, float]:
+        """
+        Get data from the sensor.
+
+        :return: A mapping with the measured temperature and humidity. Example:
+
+            .. code-block:: json
+
+                {
+                    "humidity": 30.0,
+                    "temperature": 25.5
+                }
+
+        """
+        return self.read()
+
+
+
+# vim:sw=4:ts=4:et:

requirements.txt

@@ -285,3 +285,7 @@ croniter
 
 # Support for Github
 # pytz
+
+# Support for DHT11/DHT22/AM2302 temperature/humidity sensors
+# git+https://github.com/adafruit/Adafruit_Python_DHT
+

setup.py

@@ -326,5 +326,7 @@ setup(
         'twilio': ['twilio'],
         # Support for Github integration
         'github': ['pytz'],
+        # Support for DHT11/DHT22/AM2302 temperature/humidity sensors
+        'dht': ['Adafruit_Python_DHT @ git+https://github.com/adafruit/Adafruit_Python_DHT'],
     },
 )