Abstract: The present invention provides methods for operating data loggers and in particular, software techniques useful for controlling the critical functions of a low-power-battery-operated data logger. One method initializes various memory locations upon a detection of new firmware. Another method allows a processor system belonging to a data logger to receive a high baud rate data stream while being operated in a sleep mode. Yet another method provides a highly efficient process for estimating the remaining battery capacity of a data logger's primary power source. Finally, a method is provided for protecting volatile variables during a disruption of primary power. The protected variables are written to non-volatile memory using parasitic power only.

Abstract: The present invention provides methods for operating data loggers and in particular, software techniques useful for controlling the critical functions of a low-power-battery-operated data logger. One method initializes various memory locations upon a detection of new firmware. Another method allows a processor system belonging to a data logger to receive a high baud rate data stream while being operated in a sleep mode. Yet another method provides a highly efficient process for estimating the remaining battery capacity of a data logger's primary power source. Finally, a method is provided for protecting volatile variables during a disruption of primary power. The protected variables are written to non-volatile memory using parasitic power only.

Abstract: The distance to a target is determined by transmitting a radio frequency signal comprised of a plurality of pulses to a target from a transmitter at a given transmission time, receiving a plurality of return scans at a receiver, selecting a scan meeting a predetermined parameter that includes a reflected pulse; comparing the scan with a template of a reflected pulse at different locations to select the time at which the match between the scan and the template have the closest match; and calculating the distance to the target. The signal is transmitted and received through a wall of an aperture-free container that is transparent of said radio frequency pulses. The device also includes a barrier plate that is opaque to radio frequency pulses between the transmitter and receiver.

Abstract: A system is described for discriminating between a transmitted signal and background noise comprising a transmitter adapted to transmit a signal including first and second pulses, separated by a predetermined time interval; and a receiver including a pulse detector to detect pulses received from the transmitter; a delay circuit adapted to delay transmission of the first pulse for a predetermined period of time in communication with the detector to receive a pulse therefrom; and an AND gate having an output, a first input in communication with the delay circuit and an second input in communication with the detector, the time of transmission between the pulses equaling the time delay of the delay circuit, whereby the AND gate allows transmission of a signal only when simultaneously receiving pulses from the detector and the delay circuit.