I'll See Your WISP and Raise You a WARP
After first reading, then writing about WASP, a programming language designed specifically for wireless sensor networks, I stumbled across WISP, a "Wireless Identification and Sensing Platform". Now I'm moving on to WARP, short for "Wireless Ambient Radio Power", and brought to you by the same researchers who came up with WISP.
To recap: A WISP is a standard passive RFID tag with a 16-bit general-purpose microcontroller that supports sensing and computing. The WISP is powered and read by a standard off-the-shelf RFID reader, using the power from the reader's emitted radio signals to operate the microcontroller. To date, WISPs have been used to sense light, temperature, acceleration, strain, and liquid level, and to develop security applications.
Among other features, WISPs include a range of up to 10-feet with harvested RF power, an ultra-low power TI MSP430 microcontroller, 32K of program space, 8K of storage, a real-time clock, software to sense and upload data, and development tools. For information about WISP hardware and software (including schematics and source code), go to the WISP Wiki.
Which brings us back to WARP. A WARP device lets you harvest ambient energy from TV transmission towers that is normally lost into the atmosphere. From a distance of 4.1 km, researchers in Intel's Seattle lab powered a thermometer and its LCD using 'free' energy -- pulling power out of thin air, if you will. The previously wasted, but now harvested energy, 60uW, is minimal but could potentially be used to power small devices or WISPs.
WASP, WISP, WARP. Whatever. I can hardly wait to see WHAT's next.