Encoders: allow value to be set.

encoders/encoder.py

@@ -32,5 +32,7 @@ class Encoder:
     def reset(self):
         self._pos = 0
 
-    def value(self):
+    def value(self, value=None):
+        if value is not None:
+            self._pos = value
         return self._pos

encoders/encoder_portable.py

@@ -35,5 +35,7 @@ class Encoder:
             self._pos = round(value / self.scale)  # # Improvement provided by @IhorNehrutsa
         return self._pos * self.scale
 
-    def value(self):
+    def value(self, value=None):
+        if value is not None:
+            self._pos = value
         return self._pos

encoders/encoder_timed.py

@@ -59,5 +59,7 @@ class EncoderTimed:
     def reset(self):
         self._pos = 0
 
-    def value(self):
+    def value(self, value=None):
+        if value is not None:
+            self._pos = value
         return self._pos