Here are a couple of rough sketches of architectures for the Atmosphericon system:Test one:
I could prototype a flow of information between a web application (Firefox) and a device (an Atmosphericon object) usingfile system access, which is built into every browser.

I could use the FT232R serial-USB chip as my cross-platform PC interface, and connect the serial chip to the Zigbee chip.

I could create a couple of files which emulate TX and RX buffers. I could use RealBasic to create a set of drivers which fould support all three platforms (Linux, OSX, Vista). These drivers would write all data from the virtual serial port RX buffer to an RX file, and poll the TX file for new data, writing it to the virtual TX buffer.

This might be a bit awkward, but it would work without a custom XPCOM module for Firefox.
Test two:
I have not researched this, but it occurred to me this weekend that the removable drive profile for USB might be cross-platform? If so, I might be able to fool any OS into thinking my device was a flash drive.

I would possibly have two pre-created files in the drive, and not allow the creation of any new files. I would, however, allow the TX file to be written to, and the RX file to be read.

My device would poll the TX file, and send any new data. It would delete data as it is sent. It would append the RX file with any new data that comes through the Zigbee channel.

This approach could potentially eliminate theUSB-serial driver, a serial port handler, and a serial-HTTP handler.

Some research needed!

So how do I connect a Zigbee network to a PC and the internet? MaxStream sells Zigbee USB radio modems ($250), but they are way too expensive. New Micros makes a carrier board for MaxStream’s Xbee modules ($75), which more or less fits the bill if you don’t mind the bulk, or plan to stick with the MaxStream system.

A couple of key-style USB dongles out there from different vendors. Integration Associates makes a Zigbee compliant dongle ($75) that probably could be interfaced to a module network from many of the vendors I have looked at so far. They apparently wil provide drivers for Windows, Mac and Linux.

I am not sure how easy it is to seamlessly transition from the simple proprietary networking methods provided by the module vendors to a Zigbee standard network. To be safe, I will probably selecting one of the module vendors which offer simple networking APIs then building my own gateway using a USB-serial solution like FTDI’s FT232R, then roll a serial-TCP driver for each platform.

CCS has just announced Zigbee development packages bundling boards using the Ember EM260 and the PIC16F676, the PCWH compiler, and their ICD tool ($600). As far as I can tell, no network analysis tools are included, and Ember’s hardware-based tool is undoubtedly very expensive, as they don’t list a price.

Though I have been focussing on Zigbee lately, all that Atmosphericon needs is an easy to use, robust network architecture. There are others out there. SunSPOT from Sun is an interesting project. If it gains traction, it could be a very interesting platform for ambient feedback devices. It’s pretty hardware-heavy, as all Java solutions seem to be, but it could attract a lot of developers, aspecially if the hardware becomes gets more flexible/customizable as time goes on.