So now I need to decide:

Hardware addresses

Do I need to buy a MAC address block? Do I need to buy an IEEE address block? Is there any way I can do without either one? The experimenter community should buy a block of each and sell them off in small amounts. Also, they seem redundant. When I have a device with ethernet and zigbee both, I have two nearly identical 64bit addresses. Both expensive, too!

Core component makeup

I also need to decide between a highly-integrated solution (like ConnectOne for Internet and and TI for Zigbee) and something I roll myself using cheap Microsoft parts. My choices now are:

1. Microchip Ethernet controller for the Ethernet solution. Lowest cost I think.
2. Wiznet for the Ethernet solution. Probably most robust, lower code overhead.
3. ConnectOne would be even more robust and simpler (includes DHCP, keepalive, etc), but it would be more expensive.
4. TI would likely be the most robust, lowest code overhead Zigbee solution, but it would be the most expensive.
5. Microchip would probably be the cheapest Zigbee solution, but it would require a micro to hold the stack and do all the work. If I’m lucky, the Zigbee stack could fit in the same micro with the Ethernet stack.

Module first draft

Should I do a very quick first draft using modules? If so, are there any that offer a path to a custom component-level solution?  I doubt it.  I probably need to break down and admit the same thing that everyone else has: that the Digi-style smart ethernet connector, and the Xbee, are the best way to go for prototyping and even small volume production.  About $50 parts cost, or about $80 my sale price for one-off production.

If I go this route, I clearly will NOT make a single design for gateway and devices.

What is the perfect first draft of a base system for an aio? Well, much of the design is dependent on the type of inputs and outputs. But all devices will have the same architectural requirements. So first I can nail those down. Then, I might be able to come up with a simple set of inputs and outputs that would cover a range of prototype devices.

One thing I should do is list ten or twenty device ideas and see if I can find a common hardware definition to support them all.

What about a USB MINI-B connector, and a Zigbee radio? This is pretty complicated. But it would allow one to use the system with a PC, or without. With a local control system, or with a network control system.

On the other hand, if I set a requirement that every system requires an Ethernet gateway device, then the Ethernet solution could also be used in either way.

And this would lower the cost and complexity of the individual devices. But it would limit the system from the user’s point of view. Some users want peripherals, some want ambient objects.

One argument is that a radio device could sit on your desk as easily as a USB peripheral. But it has the added advantage that it could just as easily sit anywhere else in your home.

The disadvantage of the radio/ethernet solution only is that a minimum solution is always two devices.

• I think radio is key. This should be all about radio.
• Radio opens up the possibility of battery-powered devices. Complex relationships between devices.
• Possibly even a headless meta-device, though that might take a fundamental rethinking of the whole system?
• So, can I possibly support a USB solution, a radio solution and an ethernet solution, all at the same time? Probably not.
• I imagine that three interfaces on each device would be way too complicated. After all, these are supposed to be cheap, simple.
• Maybe I can create two different types of gateways, a USB and an Ethernet flavor.
• Maybe all devices are not capable of being gateways.
• Maybe it isn’t as simple as I would like, from a user’s point of view, that all they have to do is plug things in.
• I think that a USB solution could provide its own driver? I have heard about systems which intialize as a simple universal device, HID or flash drive perhaps, then install a driver. Don’t know if this approach still works under Vista.
• If an Ethernet solution, how does a local or remote control system find the gateway? With a USB-serial system, software can pretty easily poll all possible ports until it gets an expected response.

One use of the eStarling frame would be to prototype the Twitter Sampler aio.

The basic idea is a widget that sends your friend’s Twitters to an ambient display.  In keeping with the principles of the aiosphere, this object should not look like a computer display.

I imagine a graphics system with 1. a background image of coarse-weave fabric, and 2. a text overlay system which uses an embroidery-like font.

The display would be framed in an ornate wood picture frame.The result would be a dynamic ‘needlework’ sampler. If you’re not familiar with this historical practice, this Wikipedia article is a good start.

In final form this device would follow aiosphere principles and send very small amounts of data, offloading processing complexity to the devices at either end.

For a proof of concept one could write PC-side code that adds text to an image and emails it to the eStarling.

I began making USB desktop extension devices in early 2004.  My first design was a n LCD text display.  My second design was a USB RGB lamp.  This first proto uses the USB high power mode and a high-brightness RGB module by Lamina.  I designed the PCB as a retrofit to a cheap Ikea lamp.  I wrote a simple VB app to test basic functionality.  It works beautifully.