I finally came up with a different plan to trigger different processing sketches on the raspberry pi. I first installed the PitFT from Adafruit. The steps to install are:

 

cd ~

wget https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/adafruit-pitft.sh

chmod +x adafruit-pitft.sh

sudo ./adafruit-pitft.sh

 

You than have a chance to tell Pi how to display the screen. More information can be found here.

Since I'm using VNC viewer which I installed on my laptop and already comes with Raspberry Pi , I chose to boot the screen to desktop. Now I can control the Raspberry PI with my laptop and run processing sketches on the Pi.

 

 

Testing the smaller screen again.

 

 

So the display appears to be great for sketches, Next will be installing a Arcade Button on the PiFace, I have noticed my cat Jim  likes to watch the mouse on the screen. Now the PiFace has buttons but the buttons are too small for her to press.