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WISP: Wireless Identification and Sensing Platform

The WISP Challenge is closed at this time, but WISPs are likely still available. Please visit for up-to-date information.

What is WISP?

image wispgen3hw.JPG
WISP stands for Wireless Identification and Sensing Platform. The term “Identification” comes from “Radio Frequency Identification” (RFID). WISPs have the capabilities of RFID tags, but also support sensing and computing. Like any passive RFID tag, WISP is powered and read by a standard off-the-shelf RFID reader, harvesting the power it uses from the reader's emitted radio signals. WISPs have been used to sense quantities such as light, temperature, acceleration, strain, liquid level, and to investigate embeddeded security. Most of the work on WISP so far has involved single WISPs performing sensing or computing functions. We think the next phase of WISP work will involve the interaction of many WISPs, and thus allow an exciting exploration of a new battery-free form of wireless sensor networking.

Most people are familiar with RFID tags. Most common are passive RFID tags, where a battery-less IC device harvests power from a nearby RFID reader and uses it to respond to the reader with an identification number. Two broadly adopted standards for this technology are the Electronic Product Code (EPC) Class 1 Generation 1 and Class 1 Generation 2 standards, which operate in the Ultra High Frequency (UHF) bands. The standard is led by EPCGlobal.

WISPs are powered by harvested energy from off-the-shelf UHF RFID readers. To a RFID reader, a WISP is just a normal EPC gen1 or gen2 tag; but inside the WISP, the harvested energy is operating a 16-bit general purpose microcontroller. The microcontroller can perform a variety of computing tasks, including sampling sensors, and reporting that sensor data back to the RFID reader. WISPs have been built with light sensors, temperature sensors, and strain gauges. WISPs can write to flash and perform cryptographic computations.

WISP is a project of Intel Research Seattle with significant input from students and faculty of the University of Washington. The lead investigator of the WISP project is Joshua R. Smith, Principal Engineer at Intel Research Seattle. The key WISP design and development personnel are Alanson Sample (Intel Research Seattle & UW EE Grad student), Dan Yeager (UW EE Grad student), and Polly Powledge (Intel Research Seattle engineer). The publications list below documents contributions from others at Intel and UW.
WISPs have these features:

  • Up to 10ft range with harvested RF power
  • Ultra-low power MSP430 microcontroller
  • 32K of program space, 8K of storage
  • Light, temperature and 3D-accelerometers
  • Backscatter communication to reader
  • Reader to WISP communication (ASK)
  • Real-time clock
  • Storage capacitor (to sense without reader)
  • Voltage sensor (measures stored charge)
  • Extensible hardware (to add new sensors)
  • HW UART & GPIO for external connections
  • Works with select EPC Class 1 Gen 2 readers
  • WISP software to sense and upload data
  • Reader application to drive WISP
  • Industry standard development tools
  • Access to hardware design and source code

For more information about WISP hardware and software, see the Getting Started, Documentation and Learning sections of this wiki. You'll find schematics, instructions for getting the source code, demo reader applications, and lots of other WISP resources there.

Research and Publications

WISP Challenge

The combination of RFID and sensing will embed computing deeply in the physical world. To explore new applications, we have developed the Wireless Identification and Sensing Platform (WISP), a programmable, battery-free UHF RFID tag equipped with sensors. We are now calling for research proposals so that we may give WISPs to collaborators in the academic research community.

Possible Uses

  • Object state monitoring, e.g., for cold-chains
  • Instrumented environments
  • Activity inference
  • Lightweight privacy and security
  • RFID protocols for sensor data
  • Intermittent power and RFID OS issues
  • Novel user interfaces, e.g., gestures
  • Physically embedded sensing
  • Novel sensor devices
  • Non-intrusive physiological monitoring
  • Low-power communication
  • Measurement of RFID systems
  • Educational projects

Flexible RFID Reader

We have also developed a programmable RFID reader using the USRP software radio platform. We will make it available as source code. This reader can be used with standard EPC Class 1 Gen 2 RFID tags, or with the WISP to create a system in which both tag and reader can be re-programmed from the physical layer on up.

How to Apply

Update September 2010: The WISP Challenge is closed at this time, but WISPs are likely still available. Please visit for up-to-date information.

wisp_challenge.txt · Last modified: 2018/10/04 21:51 by