Add movement counter to WeDo 2.0 Motion Sensor

buildhat/wedo.py

@@ -36,14 +36,28 @@ class MotionSensor(Device):
     :raises DeviceError: Occurs if there is no motion sensor attached to port
     """
 
+    default_mode = 0
+
     def __init__(self, port):
         """
         Initialise motion sensor
 
         :param port: Port of device
         """
         super().__init__(port)
-        self.mode(0)
+        self.mode(self.default_mode)
+
+    def set_default_data_mode(self, mode):
+        """
+        Set the mode most often queried from this device.
+
+        This significantly improves performance when repeatedly accessing data
+
+        :param mode: 0 for distance (default), 1 for movement count
+        """
+        if mode == 1 or mode == 0:
+            self.default_mode = mode
+            self.mode(mode)
 
     def get_distance(self):
         """
@@ -52,4 +66,26 @@ def get_distance(self):
         :return: Distance from motion sensor
         :rtype: int
         """
-        return self.get()[0]
+        return self._get_data_from_mode(0)
+
+    def get_movement_count(self):
+        """
+        Return the movement counter
+
+        This is the count of how many times the sensor has detected an object
+        that moved within 4 blocks of the sensor since the sensor has been
+        plugged in or the BuildHAT reset
+
+        :return: Count of objects detected
+        :rtype: int
+        """
+        return self._get_data_from_mode(1)
+
+    def _get_data_from_mode(self, mode):
+        if self.default_mode == mode:
+            return self.get()[0]
+        else:
+            self.mode(mode)
+            retval = self.get()[0]
+            self.mode(self.default_mode)
+            return retval