CardReader Rhomobile example

I have an application that will reader credit cards and am trying to implement that functionality in Ruby using the CardReader module. According to the documentation (http://edgedocs.rhomobile.com/rhoelements/cardreader), "By default the Ruby Object 'CardReader' will exist on the current page and can be used to interact directly with the CardReader". However when I run the application, and get to the point of enabling the reader, I get this error:

"e.message""uninitialized constant Controller::CardReader"

In my erb file I am using an ajax call to enable the CardReader:

  function enableScanner() {

    $.get('/app/Order/enable_cardReader', {});

  }

In my controller I am attempting to enable the CardReader:

  def enable_cardReader

    begin

      CardReader.enable

      CardReader.pinTimeout = '30000';

      CardReader.pinEntry = 'OFF';

      CardReader.readEvent = url_for(:action => :cardReader_callback)

    rescue Exception => e

      puts e.message

    end

  end

Does anyone have a working example of how to use the CardReader funtionality?

Thank you.