Simplified MCP3008 sensor backend by letting it extend SensorBackend

platypush/backend/sensor/__init__.py

@@ -1,28 +1,37 @@
+import time
+
 from platypush.backend import Backend
 from platypush.message.event.sensor import SensorDataChangeEvent, \
     SensorDataAboveThresholdEvent, SensorDataBelowThresholdEvent
 
 
 class SensorBackend(Backend):
-    def __init__(self, thresholds=None, *args, **kwargs):
+    def __init__(self, thresholds=None, poll_seconds=None, *args, **kwargs):
         """
-        Thresholds is either a scalr value or a dictionary.
+        Params:
+            -- thresholds: Thresholds can be 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.
+            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}
+            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}
+
+            -- poll_seconds: If set, the thread will wait for the specificed
+                number of seconds between a read and the next one.
         """
 
         super().__init__(**kwargs)
+
         self.data = None
         self.thresholds = thresholds
+        self.poll_seconds = poll_seconds
 
     def get_measurement(self):
         raise NotImplementedError('To be implemented in a derived class')
@@ -56,6 +65,9 @@ class SensorBackend(Backend):
 
             self.data = new_data
 
+            if self.poll_seconds:
+                time.sleep(self.poll_seconds)
+
 
 # vim:sw=4:ts=4:et:
 

platypush/backend/sensor/mcp3008.py

@@ -1,45 +1,11 @@
-import time
-
-from platypush.backend import Backend
+from platypush.backend.sensor import SensorBackend
 from platypush.context import get_plugin
-from platypush.message.event.sensor import SensorDataChangeEvent
-from platypush.plugins.gpio.sensor.mcp3008 import GpioSensorMcp3008Plugin
 
 
-class SensorMcp3008Backend(Backend):
-    last_measurement = {}
-
-    def __init__(self, poll_seconds, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.poll_seconds = poll_seconds
-        self.logger.info('Initialized MCP3008 analog sensors backend')
-
-
-    def send_message(self, msg):
-        pass
-
-
-    def run(self):
-        super().run()
+class SensorMcp3008Backend(SensorBackend):
+    def get_measurement(self):
         plugin = get_plugin('gpio.sensor.mcp3008')
-
-        while not self.should_stop():
-            try:
-                measurement = plugin.get_measurement().output
-            except:
-                plugin = get_plugin('gpio.sensor.mcp3008', reload=True)
-
-            new_measurement = {}
-            for key in measurement.keys():
-                if key not in self.last_measurement \
-                        or measurement[key] != self.last_measurement[key]:
-                    new_measurement[key] = measurement[key]
-
-            if new_measurement:
-                self.bus.post(SensorDataChangeEvent(data=new_measurement))
-
-            self.last_measurement = measurement
-            time.sleep(self.poll_seconds)
+        return plugin.get_data().output
 
 
 # vim:sw=4:ts=4:et: