WISAN

I've been keeping busy lately creating a wireless sensor network called WISAN, Wireless Intelligent Sensor and Actuator Network. It's part of a NYSERDA project for structual health monitoring. The idea is to put a network of sensors all over a bridge, capture the vibrations, create a signature, and use changes in the signature over time to pinpoint structual changes.

As part of the project, we needed a wireless sensor network. We didn't like any of the sensors currently on the market when we started in October of 2003. By Christmas-time, we had selected the Texas Instruments msp430 line of low-power highly integrated microprocessors, and the Chipcon CC2420 IEEE 802.15.4 radio. As it turns out, the Berkeley Telos project made the same decision, as have a couple of other projects.

We have, I think, a sublime design that puts the processor and radio on a 4-layer board with integral PCB antenna, and two 20-pin connectors on opposite corners. Then the power supply / I/O board need only be double-sided. We've got:

LCD display boards (top,bot).
sensor board with strain, temp/humidity, and accellerometers (top).
JTAG pass-thru boards (top,bot).

and we're working on a prototyping board that brings all the signals out to IDC connectors. The preliminary price of a development kit with two nodes (processor/radio and prototyping board) is US$200. The preliminary price of a processor/radio board is US$100 quantity one, US$80 Q100, and US$40 Q1000.

Here are some pictures of the main processor/radio board:
front of sensor node oblique view of front of sensor node back of sensor node

Russell Nelson

Last modified: Tue Aug 24 20:14:43 EDT 2004