Lowered minimal battery voltage and added ir sensor example

docs/source/lib/IRSensor.rst

@@ -4,4 +4,19 @@ Infrared Sensor
 ****************
 
 .. autoclass:: compLib.IRSensor.IRSensor
-   :members:
+   :members:
+
+Examples
+=========
+
+Testing analog sensors
+-------------------------
+
+.. code-block:: python
+
+   from compLib import IRSensor
+
+   ir = IRSensor.IRSensor()
+
+   while True:
+      print ("left: {}  middle: {}  right: {}".format(ir.bottom_left_analog(), ir.bottom_middle_analog(), ir.bottom_right_analog()))