Já várias familias me pediram para dar umas dicas de Processing, mas ando muito escasso de tempo, e há dias deparei-me com este site, além de ter exemplos de circuitos muito básicos com Arduino, mostra também como integrar o Processing

happy sketching

"The Arduino meets Processing project intends to make it as easy as possible for anyone to explore the world of physical computing. All you need is an Arduino board as well as the Arduino and Processing software, which you can download on their project websites.
On this website we explain how to:
1. set up electronic circuits with various kinds of sensors,
2. control and measure the sensors with the Arduino board,
3. send the data to the computer,
4. and use the received values to generate computer graphics with Processing."
Arduino meets ProcessingProcessing.org