It's from my another blog for Arduino, http://arduino-er.blogspot.com/.
In this example, Android device can write analog output (DAC0/DAC1) and read analog input (A0) on Arduino Due board by using ADK, WITH GRAPHICAL DISPLAY on Android. The video show how it work, with DAC1 pin and A0 pin connected together, such that the analog out loop back to analog input.
To know how: Read analog input at Arduino Due, display on Android graphically@Arduino-er.