Refactoring sensor backend and added SensorSerialBackend

platypush/backend/sensor/__init__.py

@@ -0,0 +1,60 @@
+from platypush.backend import Backend
+from platypush.message.event.sensor import SensorDataChangeEvent, \
+    SensorDataAboveThresholdEvent, SensorDataBelowThresholdEvent
+
+
+class SensorBackend(Backend):
+    def __init__(self, thresholds=None, *args, **kwargs):
+        """
+        Thresholds is either a scalr value or a dictionary.
+
+        If set, SensorDataAboveThresholdEvent and SensorDataBelowThresholdEvent
+        events will be triggered whenever the measurement goes above or below
+        that value.
+
+        Set it as a scalar if your get_measurement() code returns a scalar,
+        as a dictionary if it returns a dictionary of values.
+
+        For instance, if your sensor code returns both humidity and temperature
+        in a format like {'humidity':60.0, 'temperature': 25.0}, you'll want to
+        set up a threshold on temperature with a syntax like {'temperature':20.0}
+        """
+
+        super().__init__(**kwargs)
+        self.measurement = None
+        self.thresholds = thresholds
+
+    def get_measurement(self):
+        raise NotImplementedError('To be implemented in a derived class')
+
+    def run(self):
+        super().run()
+
+        while not self.should_stop():
+            new_data = self.get_measurement()
+            if self.data is None or self.data != new_data:
+                self.bus.post(SensorDataChangeEvent(data=new_data))
+
+            if self.thresholds:
+                if isinstance(self.thresholds, dict) and isinstance(new_data, dict):
+                    for (measure, threshold) in self.thresholds.items():
+                        if measure not in new_data:
+                            continue
+
+                        if new_data[measure] > threshold and (self.data is None or (
+                                measure in self.data and self.data[measure] <= threshold)):
+                            self.bus.post(SensorDataAboveThresholdEvent(data=new_data))
+                        elif new_data[measure] < threshold and (self.data is None or (
+                                measure in self.data and self.data[measure] >= threshold)):
+                            self.bus.post(SensorDataBelowThresholdEvent(data=new_data))
+                else:
+                    if new_data > threshold and (self.data is None or self.data <= threshold):
+                        self.bus.post(SensorDataAboveThresholdEvent(data=new_data))
+                    elif new_data < threshold and (self.data is None or self.data >= threshold):
+                        self.bus.post(SensorDataBelowThresholdEvent(data=new_data))
+
+            self.data = new_data
+
+
+# vim:sw=4:ts=4:et:
+

platypush/backend/sensor/serial.py

@@ -0,0 +1,21 @@
+import serial
+
+from platypush.backend.sensor import SensorBackend
+from platypush.context import get_plugin
+
+
+class SensorSerialBackend(SensorBackend):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def get_measurement(self):
+        plugin = get_plugin('serial')
+        return plugin.get_data().output
+
+    def run(self):
+        self.logger.info('Initialized serial backend')
+        super().run()
+
+
+# vim:sw=4:ts=4:et:
+

platypush/message/event/sensor/__init__.py

@@ -2,8 +2,21 @@ from platypush.message.event import Event
 
 
 class SensorDataChangeEvent(Event):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+    def __init__(self, data, *args, **kwargs):
+        super().__init__(data=data, *args, **kwargs)
+        self.data = data
+
+
+class SensorDataAboveThresholdEvent(Event):
+    def __init__(self, data, *args, **kwargs):
+        super().__init__(data=data, *args, **kwargs)
+        self.data = data
+
+
+class SensorDataBelowThresholdEvent(Event):
+    def __init__(self, data, *args, **kwargs):
+        super().__init__(data=data, *args, **kwargs)
+        self.data = data
 
 
 # vim:sw=4:ts=4:et: