The primary goal of a universal smart transducer interface is the provision of a framework that helps to reduce the complexity of large distributed real-time systems by introducing precisely specified (in the value domain and in the temporal domain) and small interfaces between smart transducers and their users. This paper presents a universal smart transducer interface that can be implemented on top of different real-time communication systems. It integrates a time-triggered communication protocol with an interface file system that provides the sources and sinks for the exchanged information. The final section discusses an implementation of this interface on a low cost (less than 1 $) commercial off the shelf microcontroller.

The paper describes a smart transducer interface that hides the internal node properties and allows a decoupling of applications from communication properties like message timing, flow control and bus access. The smart transducer interface incorporates three different interfaces, for real-time service, diagnostic/maintenance and configuration/planning. A further decomposition of a real time system will be provided by hiding the sensor properties behind a data structure that represents a model of the environment the sensors are observing. This data structure can be serviced by a sensor fusion node and reduces the complexity of the application. An application of the presented concepts is described in a case study featuring a mobile robot.

We describe our first efforts to develop a set of off-the-shelf hardware components that ordinary people could connect to build a simple but useful class of embedded systems. The class of systems, which we call monitor/control systems, is composed primarily of sensors -- light, motion, sound, contact, and other types -- and output devices -- light-emitting diodes, beeping speakers, or even electric relays that control electric appliances like lamps. For example, one monitor/control system would detect if a house's garage door was open at night, and would blink an LED inside the house to alert the homeowner of this normally undesirable situation. Today, configuring even the most basic monitor/control system requires knowledge of electronics and programming. We seek to create a set of building blocks, which we call eBlocks, that would enable someone with no knowledge of electronics or programming to be able to build simple but useful monitor/control systems. We are creating eBlocks largely by incorporating intelligence into previously dumb sensors and output devices, and by developing a set of standards and methods that enable eBlocks to work together seamlessly when connected. eBlocks have only recently become possible due to the extremely low cost, low power, and small size of embedded microprocessors. We describe our first results of creating a basic class of eBlocks, Boolean eBlocks, that from a user's perspective transmit or receive only "yes" or "no" signals. We discuss the internal eBlock design, eBlock system design issues and decisions, and several eBlock-based systems designed by ourselves and by undergraduate students.