Tidy up some lidar stuff for testing and clarity.

tracking/lidar_servicer.py

@@ -3,12 +3,13 @@ from tracking.lidar_tracker_pb2_grpc import PersonTrackingServicer
 from tracking.lidar_cache import LidarCache
 from multiprocessing import Process
 import Messaging.message_factory as mf
-
+from rplidar import RPLidar
 
 class LidarServicer(PersonTrackingServicer):
 
     def __init__(self):
-        self.cache = LidarCache(measurements=100)
+        #TODO: Put the rplidar creation in a factory or something, to make it possible to test this servicer.
+        self.cache = LidarCache(RPLidar('/dev/ttyUSB0'), measurements=100)
 
     def set_tracking_group(self, request, context):
         pass
@@ -17,7 +18,5 @@ class LidarServicer(PersonTrackingServicer):
         self.cache.stop_scanning()
 
     def start_tracking(self, request, context):
-        '''
-        Starts the lidar cache. 
-        '''
+        """Starts the lidar cache, streaming on the provided port."""
         self.cache.start_cache(mf.getZmqPubSubStreamer(request.value))