Interface Task
====================
The interface task allows a user to control the robot. It's main functions are to 
allow the user to print a circle, line, custom image, or letters (typed by the user). 
The finite state diagram is below.

.. image:: ../Images/InterfaceFSM.png

**State 0: INIT** - Prints the available user actions:

   * Draw a circle
   * Draw a triangle
   * Draw a custom image
   * Accept and write a user input

**State 1: WAIT_FOR_INPUT** - Waits for the user to input their selection. This is 
a non-blocking replacement for the 'input' python method.

**State 2: CIRCLE** - Sets the 'image' shared variable to 1. This is read later by 
the Data Task to select which image to draw.

**State 3: TRIANGLE** - Sets the 'image' shared variable to 2. This is read later by 
the Data Task to select which image to draw.

**State 4: CUSTOM** - Sets the 'image' shared variable to 3. This is read later by 
the Data Task to select which image to draw.

**State 5: TYPE** - Allows the user to type words to be written. Once a space is 
entered, the preceding chunk is saved as a word. Once a return is entered, a shared 
variable is changed to True to trigger the writing task.