Download the Processing configuration tool for ArtBus. It's name is ArtBus_term.pde.  Unzip the folder and put it in your Processing sketches folder. Don't open the sketch yet. Just get it in there ready to go.

1. Plug the ArtBus FTDI USB-to-serial adapter and at least one ArtBus board into your computer. The blue LED should come on indicating that power is on, and the green LED should blink three times showing that the ArtBus board has just been reset.
2. Open the  ArtBus_trem.pde sketch and start it.
3. Push the reset button on an ArtBus board. The green LED should blink three times, and you should see a greeting in the window. If you see a greeting in the ArtBus_term window, basic setup is done. This also means that your ArtBus devices are at serial port number 0 (zero).

Don't close ArtBus_term.pde yet -- you need to get the address of your boards.

Quirks of the FTDI serial port

If you get a blinking red LED that means you pushed the setup button by mistake. Just push the reset button and it will be ok. If the red led stays on there was an error. Press reset.

If the sketch doesn't seem to do anything and Processing prints a bunch of errors in in the editor's text window, there is an FTDI serial port problem. For extra info on the serial port and help with FTDI problems, look here.