Since  ArtBus_term  is happy now, it's time to ask each of your boards what its name is, so that you can talk to it from Processing. If the ArtBus_term.pde sketch isn't still open, open it.

One at a time, press the reset button on each board and read the greeting message in the ArtBus_term window. The address of a board is given in the first few words of the message: "Hi from A..." The address of this board is A. It also tells you what kind of board it is, (analog or digital). The address is always an upper-case letter. Make note of the addresses. You'll use these in your program.

Finish up the computer setup

Close the ArtBus_term.pde sketch. Processing allows multiple sketch windows to be open at the same time, but only one program can own the serial port at any given time.