Added GPS backend

docs/source/conf.py

@@ -221,6 +221,7 @@ autodoc_mock_imports = ['googlesamples.assistant.grpc.audio_helpers',
                         'pyHS100',
                         'grpc',
                         'envirophat',
+                        'gps',
                         ]
 
 sys.path.insert(0, os.path.abspath('../..'))

platypush/backend/gps.py

@@ -0,0 +1,103 @@
+import gps
+import threading
+import time
+
+from platypush.backend import Backend
+from platypush.message.event.gps import GPSVersionEvent, GPSDeviceEvent, GPSUpdateEvent
+
+
+class GpsBackend(Backend):
+    """
+    This backend can interact with a GPS device and listen for events.
+
+    Triggers:
+
+        * :class:`platypush.message.event.gps.GPSVersionEvent` when a GPS device advertises its version data
+        * :class:`platypush.message.event.gps.GPSDeviceEvent` when a GPS device is connected or updated
+        * :class:`platypush.message.event.gps.GPSUpdateEvent` when a GPS device has new data
+
+    Requires:
+
+        * **gps** (``pip install gps``)
+        * **gpsd** daemon running (``apt-get install gpsd`` or ``pacman -S gpsd`` depending on your distro)
+
+    Once installed gpsd you need to run it and associate it to your device. Example if your GPS device communicates
+    over USB and is available on /dev/ttyUSB0::
+
+        [sudo] gpsd /dev/ttyUSB0 -F /var/run/gpsd.sock
+
+    The best option is probably to run gpsd at startup as a systemd service.
+    """
+
+    _fail_sleep_time = 5.0
+
+    def __init__(self, gpsd_server='localhost', gpsd_port=2947, **kwargs):
+        """
+        :param gpsd_server: gpsd daemon server name/address (default: localhost)
+        :type gpsd_server: str
+        :param gpsd_port: Port of the gpsd daemon (default: 2947)
+        :type gpsd_port: int or str
+        """
+        super().__init__(**kwargs)
+
+        self.gpsd_server = gpsd_server
+        self.gpsd_port = gpsd_port
+        self._session = None
+        self._session_lock = threading.RLock()
+        self._devices = {}
+
+    def _get_session(self):
+        with self._session_lock:
+            if not self._session:
+                self._session = gps.gps(host=self.gpsd_server, port=self.gpsd_port, reconnect=True)
+                self._session.stream(gps.WATCH_ENABLE | gps.WATCH_NEWSTYLE)
+
+        return self._session
+
+    def _gps_report_to_event(self, report):
+        if report.get('class').lower() == 'version':
+            return GPSVersionEvent(release=report.get('release'),
+                                   rev=report.get('rev'),
+                                   proto_major=report.get('proto_major'),
+                                   proto_minor=report.get('proto_minor'))
+        if report.get('class').lower() == 'devices':
+            for device in report.get('devices', []):
+                if device.get('path') not in self._devices or device != self._devices.get('path'):
+                    self._devices[device.get('path')] = device
+                    return GPSDeviceEvent(path=device.get('path'), activated=device.get('activated'),
+                                          native=device.get('native'), bps=device.get('bps'),
+                                          parity=device.get('parity'), stopbits=device.get('stopbits'),
+                                          cycle=device.get('cycle'), driver=device.get('driver'))
+        if report.get('class').lower() == 'device':
+            self._devices[report.get('path')] = report
+            return GPSDeviceEvent(path=report.get('path'), activated=report.get('activated'),
+                                  native=report.get('native'), bps=report.get('bps'),
+                                  parity=report.get('parity'), stopbits=report.get('stopbits'),
+                                  cycle=report.get('cycle'), driver=report.get('driver'))
+        if report.get('class').lower() == 'tpv':
+            return GPSUpdateEvent(device=report.get('device'), latitude=report.get('lat'), longitude=report.get('lon'),
+                                  altitude=report.get('alt'), mode=report.get('mode'), epv=report.get('epv'),
+                                  eph=report.get('eph'), sep=report.get('sep'))
+
+    def run(self):
+        super().run()
+        self.logger.info('Initialized GPS backend on {}:{}'.format(self.gpsd_server, self.gpsd_port))
+
+        while not self.should_stop():
+            try:
+                session = self._get_session()
+                report = session.next()
+                event = self._gps_report_to_event(report)
+                if event:
+                    self.bus.post(event)
+            except Exception as e:
+                if isinstance(e, StopIteration):
+                    self.logger.warning('GPS service connection lost, check that gpsd is running')
+                else:
+                    self.logger.exception(e)
+
+                self._session = None
+                time.sleep(self._fail_sleep_time)
+
+
+# vim:sw=4:ts=4:et:

platypush/backend/midi.py

@@ -1,4 +1,3 @@
-import json
 import time
 
 from threading import Timer

platypush/message/event/gps.py

@@ -0,0 +1,44 @@
+from platypush.message.event import Event
+
+
+class GPSEvent(Event):
+    """
+    Generic class for GPS events
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+
+class GPSVersionEvent(GPSEvent):
+    """
+    Event usually triggered on startup or reconnection, when the GPS device advertises its version parameters
+    """
+
+    def __init__(self, release=None, rev=None, proto_major=None, proto_minor=None, *args, **kwargs):
+        super().__init__(release=release, rev=rev, proto_major=proto_major, proto_minor=proto_minor, *args, **kwargs)
+
+
+class GPSDeviceEvent(GPSEvent):
+    """
+    Event triggered when a new GPS device is connected or reconfigured
+    """
+
+    def __init__(self, path, activated=None, native=False, bps=None, parity=None, stopbits=None,
+                 cycle=None, driver=None, *args, **kwargs):
+        super().__init__(*args, path=path, activated=activated, native=native, bps=bps, parity=parity,
+                         stopbits=stopbits, cycle=cycle, driver=driver, **kwargs)
+
+
+class GPSUpdateEvent(GPSEvent):
+    """
+    Event triggered upon GPS status update
+    """
+
+    def __init__(self, device=None, latitude=None, longitude=None, altitude=None, mode=None, epv=None, eph=None,
+                 sep=None, *args, **kwargs):
+        super().__init__(*args, device=device, latitude=latitude, longitude=longitude, altitude=altitude,
+                         mode=mode, epv=epv, eph=eph, sep=sep, **kwargs)
+
+
+# vim:sw=4:ts=4:et:

requirements.txt

@@ -150,3 +150,5 @@ pyScss
 # Support for enviropHAT
 # envirophat
 
+# Support for GPS integration
+# gps

setup.py

@@ -172,6 +172,7 @@ setup(
         'Support for compiling SASS/SCSS styles to CSS': ['pyScss'],
         'Support for NFC tags': ['nfcpy>=1.0', 'ndef'],
         'Support for enviropHAT': ['envirophat'],
+        'Support for GPS': ['gps'],
         # 'Support for Leap Motion backend': ['git+ssh://git@github.com:BlackLight/leap-sdk-python3.git'],
         # 'Support for Flic buttons': ['git+https://@github.com/50ButtonsEach/fliclib-linux-hci.git']
         # 'Support for media subtitles': ['git+https://github.com/agonzalezro/python-opensubtitles#egg=python-opensubtitles']