My Arduino arrived yesterday and I jumped straight into getting it talking to Lily. Flash is able to interface with the Arduino using XMLSocket to communicate via a socket/serial proxy, but native Javascript doesn't offer anything like XMLSocket. Fortunately, Mozilla exposes a scriptable socket interface that's close enough for what we want to do.
It took a couple of hours to get it up and running, using the socket-transport-service to send messages to a java serial proxy and from there to the Arduino. On the Arduino I used SimpleMessageSystem to handle receving and sending messages. SMS is specifically intended to work with message passing programs like Max/MSP & PD, so it's a good fit for Lily. The Lily SimpleMessageSystem object is available here
Next up- removing the need for serial proxying and talking (via javaxpcom) directly to the serial port from Lily.
