Added light sensor backend

platypush/backend/sensor/light/__init__.py

@@ -0,0 +1,51 @@
+import logging
+import time
+
+import RPi.GPIO as gpio
+
+from platypush.backend import Backend
+from platypush.message.event.sensor.light import LightOnEvent, LightOffEvent
+
+
+class SensorLightBackend(Backend):
+    state = None
+
+    def __init__(self, pin, threshold=0.5, poll_seconds=0.5, **kwargs):
+        super().__init__(**kwargs)
+
+        self.pin = pin
+        self.threshold = threshold
+        self.poll_seconds = poll_seconds
+
+    def send_message(self, msg):
+        pass
+
+    def get_state(self):
+        return self.state
+
+    def run(self):
+        super().run()
+
+        gpio.setmode(gpio.BCM)
+        gpio.setup(self.pin, gpio.IN)
+        logging.info('Initialized light sensor backend on pin {}'.format(self.pin))
+
+        try:
+            while not self.should_stop():
+                value = float(gpio.input(self.pin))
+                new_state = True if value >= self.threshold else False
+
+                if self.state is not None and new_state != self.state:
+                    if new_state is True:
+                        self.bus.post(LightOnEvent())
+                    else:
+                        self.bus.post(LightOffEvent())
+
+                self.state = new_state
+                time.sleep(self.poll_seconds)
+        finally:
+            gpio.cleanup()
+
+
+# vim:sw=4:ts=4:et:
+

platypush/message/event/sensor/light/__init__.py

@@ -0,0 +1,15 @@
+from platypush.message.event import Event
+
+
+class LightOnEvent(Event):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+
+class LightOffEvent(Event):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+
+# vim:sw=4:ts=4:et:
+