Abstract: In a highly available environmental monitoring system, several slave devices are associated with either a fast polling list or a slow polling list. The fast polling list is polled by a master device more frequently than the slow polling list. A slave device is associated with the fast polling list if the slave device responds to a poll from the master device within a time period, and is associated with the slow polling list if the slave device does not respond to the poll from the master device within the time period. Furthermore, several control devices arbitrate to determine which shall be the master device for controlling several serial buses. The master device periodically switches between the plurality of serial buses to communicate with slave devices.

Abstract: An electronic game that includes a main body that consists of four panels assembled to form a four-sided pyramid having four vertexes. Each vertex serves as a node for supporting a light which may illuminate a plurality of different colors. Digital circuitry defines a color state vector at each node by illuminating one or none of the colors. Control circuitry connected to the digital circuitry is used for altering the color state of at least one of the lights as the tetrahedron is rotated. In one game, the color of the node brought to the top position changes in the color change pattern established by the color state vector. A player rotates the tetrahedron in an effort to figure out the pattern of color changes. Once the pattern is deciphered, the player makes additional rotations to achieve an object of the game such as having each vertex of the tetrahedron lighted the same color.