We have developed a simple modular platform for wireless sensing. This system allows for easy prototyping and testing of embedded sensor applications, and encapsulates much of the wireless system design and makes it reusable. All boards in the system are 1.4 inch square; the master board contains a 22 MIPS microcontroller with 12-bit ADC and a 115.2 kBps wireless link with TDMA channel sharing. A flash memory board is also available for local storage. Sensor boards can be attached to the master via a 26-pin fixed link, which provides for both direct and multiplexed connections, as well as a variety of other data protocols and power distribution. So far, constructed sensor boards include a six degree of freedom inertial measurement unit, a tactile (e.g., bend and pressure) sensor signal processing board, and a promixity sensing board based on both sonar and capacitve sensors. An ambient sensor (camera, IR, heat, sound) board is currently in testing. This platform has been used in a number of lab projects, including a wearable gait laboratory, a novel musical controller and an instrument plush bear.