basuke · May 7, 2013 07:28 · May 7, 2013
diff --git a/daidokoro-monitor.py b/daidokoro-monitor.py
@@ -0,0 +1,110 @@
+# -*- coding: utf-8
+
+import RPi.GPIO as GPIO
+import mosquitto
+import sys
+from datetime import datetime
+
+
+PINS = (18, 23, 24, 25)
+SERVER = "sample.example.com"
+
+
+def main():
+    # setup MQTT
+    conn = MQTTServer(SERVER)
+    conn.connect()
+
+    # setup GPIO
+    GPIO.setmode(GPIO.BCM)
+    [GPIO.setup(pin, GPIO.IN) for pin in PINS]
+
+    labels = range(1, len(PINS) + 1)
+    sensors = [Sensor(label, pin) for label, pin in zip(labels, PINS)]
+
+    # send initial state
+    for sensor in sensors:
+        conn.publish(*sensor.event())
+
+    while True:
+        conn.loop()
+
+        for sensor in sensors:
+            if sensor.check():
+                conn.publish(*sensor.event())
+
+
+class Sensor(object):
+    def __init__(self, label, pin):
+        self.pin = pin
+        self.state = GPIO.input(self.pin)
+        self.topic = "home/kitchen/gas/%s" % label
+
+    def check(self):
+        state = self.state
+        self.state = GPIO.input(self.pin)
+        return (state != self.state)
+
+    def event(self):
+        state = "ON" if self.state else "OFF"
+        msg = ' '.join([state, utctimestamp()])
+
+        return (self.topic, msg)
+
+
+class MQTTServer(object):
+    def __init__(self, server):
+        self.server = server
+        self.client = mosquitto.Mosquitto("Daidokoro-monitor", obj=self)
+        self.connected = False
+
+        def on_connect(self, rc):
+            if rc != 0:
+                log("Cannot connect to server. Exit.")
+                sys.exit(255)
+
+            log("Connected successfully.")
+            self.connected = True
+
+        def on_disconnect(self, rc):
+            log("Disconnected. Try to connect again.")
+            self.connected = False
+
+            self.reconnect()
+
+        self.client.on_connect = on_connect
+        self.client.on_disconnect = on_disconnect
+
+    def connect(self):
+        log("Connecting to MQTT server.")
+        self.client.connect(self.server)
+        self.wait_connection()
+
+    def reconnect(self):
+        log("Reconnecting to MQTT server.")
+        self.client.reconnect()
+        self.wait_connection()
+
+    def publish(self, topic, payload):
+        log("Publish %s => %s" % (topic, payload))
+        self.client.publish(topic, payload, retain=True)
+
+    def loop(self, timeout=-1):
+        self.client.loop(timeout=timeout)
+
+    def wait_connection(self):
+        while not self.connected:
+            self.loop()
+
+
+def utctimestamp():
+    now = datetime.utcnow().replace(microsecond=0)
+    return now.isoformat() + 'Z'
+
+
+def log(msg):
+    print msg
+
+
+if __name__ == '__main__':
+    main()