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Posey: Instrumenting a Poseable Hub and Strut Toy
    We describe Posey, a computationally-enhanced hub-and-strut construction kit for learning and play. Posey employs a ball and socket connection that allows users to move the parts of an assembled model. Hubs and struts are optocoupled through the ball and socket joints using infrared LEDs and photosensors. Wireless transmitters in the hubs send connection and geometry information to a host computer. The host computer assembles a representation of the physical model as the user creates and configures it. Application programs can then use this representation to control computational models in particular domains.