Scale values of type 'float' when returned from special sensor classes (#330)

* Scale values of type 'float' when returned from special sensor classes

Fixes #329

Author: ddemidov

ev3dev/core.py

@@ -1613,6 +1613,7 @@ def __init__(self, address=None, name_pattern=SYSTEM_DEVICE_NAME_CONVENTION, nam
         self._bin_data_format = None
         self._bin_data_size = None
         self._bin_data = None
+        self._mode_scale = {}
 
     __slots__ = [
 # ~autogen generic-class-slots classes.sensor>currentClass
@@ -1632,8 +1633,21 @@ def __init__(self, address=None, name_pattern=SYSTEM_DEVICE_NAME_CONVENTION, nam
     '_bin_data_format',
     '_bin_data_size',
     '_bin_data',
+    '_mode_scale'
     ]
 
+    def _scale(self, mode):
+        """
+        Returns value scaling coefficient for the given mode.
+        """
+        if mode in self._mode_scale:
+            scale = self._mode_scale[mode]
+        else:
+            scale = 10**(-self.decimals)
+            self._mode_scale[mode] = scale
+
+        return scale
+
 # ~autogen generic-get-set classes.sensor>currentClass
 
     @property
@@ -2116,7 +2130,7 @@ def distance_centimeters(self):
         if self.auto_mode:
             self.mode = self.MODE_US_DIST_CM
 
-        return self.value(0)
+        return self.value(0) * self._scale('US_DIST_CM')
 
     @property
     def distance_inches(self):
@@ -2128,7 +2142,7 @@ def distance_inches(self):
         if self.auto_mode:
             self.mode = self.MODE_US_DIST_IN
 
-        return self.value(0)
+        return self.value(0) * self._scale('US_DIST_IN')
 
     @property
     def other_sensor_present(self):
@@ -2309,7 +2323,7 @@ def sound_pressure(self):
         if self.auto_mode:
             self.mode = self.MODE_DB
 
-        return self.value(0)
+        return self.value(0) * self._scale('DB')
 
     @property
     def sound_pressure_low(self):
@@ -2321,7 +2335,7 @@ def sound_pressure_low(self):
         if self.auto_mode:
             self.mode = self.MODE_DBA
 
-        return self.value(0)
+        return self.value(0) * self._scale('DBA')
 
 class LightSensor(Sensor):
 
@@ -2361,7 +2375,7 @@ def reflected_light_intensity(self):
         if self.auto_mode:
             self.mode = self.MODE_REFLECT
 
-        return self.value(0)
+        return self.value(0) * self._scale('REFLECT')
 
     @property
     def ambient_light_intensity(self):
@@ -2372,7 +2386,7 @@ def ambient_light_intensity(self):
         if self.auto_mode:
             self.mode = self.MODE_AMBIENT
 
-        return self.value(0)
+        return self.value(0) * self._scale('AMBIENT')
 
 
 # ~autogen

templates/special-sensors.liquid

@@ -87,7 +87,7 @@ assign propName = prop.propertyName | upcase | underscore_spaces%}
 
         return {%
   for value_index in mapping.sourceValue
-  %}self.value({{ value_index }}){% unless forloop.last %}, {% endunless %}{%
+  %}self.value({{ value_index }}){% if mapping.type contains 'float' %} * self._scale('{{ mode }}'){% endif %}{% unless forloop.last %}, {% endunless %}{%
   endfor %}
 {% endfor %}{%
 endfor %}