Tidy up lidar tracker and its protos

persontracking/lidar_cache.py

@@ -4,6 +4,7 @@ from threading import Thread
 from persontracking import algorithms
 import zmq
 
+
 class LidarCache():
     '''
     A class that retrieves scans from the lidar,
@@ -14,15 +15,18 @@ class LidarCache():
     tracking_group_number = -1
     currentGroups = None
     groupsChanged = []
-    
-    def __init__(self, port, measurements=100):
-        self.port = port
+    port = None
+
+    def __init__(self, measurements=100):
         self.lidar = RPLidar('/dev/ttyUSB0')
         self.measurements = measurements
         print('Info: ' + self.lidar.get_info())
         print('Health: ' + self.lidar.get_health())
 
     def start_cache(self):
+        if self.port is None:
+            print('ERROR: Port has not been set!')
+            return
         self.thread = Thread(target=self.do_scanning)
         self.thread.start()
 
@@ -30,7 +34,6 @@ class LidarCache():
         '''
         Performs a scan for the given number of iterations.
         '''
-
         # Create the 0MQ socket first. This should not be passed between threads.
         self._socket = self._create_socket()
         self._socket.bind("tcp://*:" + str(self.port))
@@ -40,9 +43,10 @@ class LidarCache():
             if(not self.run):
                 break
 
-            # Now process the groups. 
+            # Now process the groups.
             if self.currentGroups is not None:
-                self.currentGroups = algorithms.assign_groups(self.currentGroups, algorithms.calc_groups(scan))
+                self.currentGroups = algorithms.assign_groups(
+                    self.currentGroups, algorithms.calc_groups(scan))
             else:
                 self.currentGroups = algorithms.calc_groups(scan)
 
@@ -56,4 +60,3 @@ class LidarCache():
 
     def _create_socket(self):
         return zmq.Context.instance().socket(zmq.PUB)
-