Abstract: Disclosed DSI3 slave devices may enhance the data rate of the DSI3 bus using modified nibble encoding, pulse shaping, spectral shaping, and/or message preambles to provide chip time and level tracking. In one embodiment, there is provided a communications method that includes: converting a binary data stream into a ternary unipolar non-return-to-zero level channel signal; and driving the channel signal as an electrical current on a signal conductor. The converting uses an encoder that maps binary nibbles to a set of ternary triplets, each triplet in the set having an average level between 2/3 and 4/3 inclusive, and each triplet including at least one internal transition between levels.

Abstract: Methods and transceivers are provided for enabling fast-data messages on a local interconnect network (LIN) compatible bus. One illustrative slave transceiver embodiment includes: a comparator and a digital-to-analog converter (DAC). The comparator detects amplitude modulation of a bias voltage at a first baud rate on a serial bus line to receive a first LIN frame header having a frame identifier for a fast-data frame. The DAC responsively drives a fast-data response message having an expanded payload and/or a higher baud rate on the serial bus line.

Abstract: An obstacle monitoring system includes a first transducer that obtains a first distance measurement to an obstacle using a first linear frequency modulated (“LFM”) chirp. The system further includes a second transducer, able to operate concurrently with the first transducer, that obtains a second distance measurement to the obstacle using a second LFM chirp. The second LFM chirp has an inverted slope or shifted center frequency compared to the first LFM chirp. The system further includes a controller that processes the first and second distance measurements to determine a motion-compensated distance measurement to the obstacle.

Abstract: In one form, an acoustic distance measuring circuit includes a transmitter amplifier, an acoustic transducer, and a sensing circuit. The sensing circuit includes an input adapted to be coupled to the acoustic transducer, a first correlation output for providing a chirp tail correlation signal, and a second output for providing a full chirp correlation signal. The sensing circuit provides the chirp tail correlation signal in response to correlating a chirp tail signal pattern with a received signal, and provides a full chirp correlation signal in response to correlating a full chirp signal pattern with the received signal. Further, the acoustic distance measuring circuit includes a controller adapted to be coupled to the sensing circuit that has a first input for receiving the chirp tail correlation signal and the full chirp correlation signal for determining a short range time of flight signal and a long range time of flight signal.

Abstract: In one form, an acoustic signal is generated for an acoustic transducer, where the acoustic transducer is susceptible to reverberation that defines a close proximity indication zone. The start of a close proximity indication zone window is defined after the generation of the acoustic signal at a first time. During the close proximity indication zone window, a signal is received from the acoustic transducer. When the signal is received, an obstacle is detected in the close proximity indication zone if the magnitude of a first pulse received from the transducer at a second time is less than a first threshold but greater than a second threshold for a debounce time. Additionally, a magnitude of a second pulse received from the transducer outside the close proximity indication zone window at a third time should be less than the second threshold but greater than a third threshold for the debounce time.

Abstract: Methods and transceivers are provided for enabling fast-data messages on a local interconnect network (LIN) compatible bus. One illustrative slave transceiver embodiment includes: a comparator and a digital-to-analog converter (DAC). The comparator detects amplitude modulation of a bias voltage at a first baud rate on a serial bus line to receive a first LIN frame header having a frame identifier for a fast-data frame. The DAC responsively drives a fast-data response message having an expanded payload and/or a higher baud rate on the serial bus line.

Abstract: In one form, a method for acoustic distance measurement includes generating an acoustic signal with an acoustic transducer at a first time. A pulse is detected with the acoustic transducer in response to the acoustic signal encountering an obstacle within a predetermined distance. Detecting the pulse includes detecting a second time relative to the first time when a magnitude of the pulse rises above a predetermined threshold, and detecting a peak magnitude of the pulse. A correction ratio is determined as a ratio of the predetermined threshold to the peak magnitude of the pulse. A correction time is determined in response to the correction ratio. A corrected time-of-flight is determined by adjusting the second time by the compensation time.

Abstract: In one form, an acoustic signal is generated for an acoustic transducer, where the acoustic transducer transmits the acoustic signal to determine a first position of an obstacle. In response to the acoustic signal encountering the obstacle within a predetermined distance, an echo, or pulse, is detected at the acoustic transducer. At a first time, a magnitude is detected in response to a rising edge of the pulse intersecting a determined threshold. A second magnitude is detected in response to the detection of a first peak of the pulse. A time of flight of the acoustic signal, within the predetermined distance, is determined when a compensation time is extracted from a correction calculation algorithm in response to detecting the first magnitude and the second magnitude. The compensation time is subtracted from the first time, and the difference of the compensation time and the first time is the time of flight.

Abstract: Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states with novel parameter measurements. In an illustrative embodiment of a piezoelectric-based sensor having response-parameter-based fault diagnosis, the sensor includes a piezoelectric transducer and a controller. The controller drives the piezoelectric transducer to generate bursts of acoustic energy and, based on a response of the piezoelectric transducer to said driving, identifies a corresponding transducer state from a set of potential states including multiple transducer fault states.

Abstract: Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states with novel parameter measurements. In an illustrative embodiment of a piezoelectric-based sensor having a shorted-reverberation based resonant frequency measurement, the sensor includes a piezoelectric transducer that provides residual reverberation after being driven. The sensor further includes a controller that provides a low impedance path for the piezoelectric transducer during the residual reverberation and that measures current through the low impedance path to determine a resonant frequency of the piezoelectric transducer.

Abstract: Composite burst signaling to provide robust multi-channel sensor array performance in systems for parking assistance, blind spot monitoring, and driver assistance. An illustrative method embodiment includes driving an acoustic transducer to send composite acoustic bursts. Each composite acoustic burst includes multiple individual bursts associated with respective frequency bands, the frequency band arrangement providing a source-specific burst signature. The method further includes receiving self-generated echo signals responsive to the composite acoustic bursts from the transducer and potentially including extra echoes responsive to acoustic bursts from other sources; categorizing received echo signals by source based on the burst signature; and using the self-generated echoes exclusive of the extra echoes to determine a distance or time of flight from the transducer.

Abstract: An obstacle monitoring system includes a transducer that receives an ultrasonic echo from an obstacle and generates a signal based on the echo. The system further includes a controller coupled to the transducer that is calibrated based on a frequency response of the transducer and a coupling circuit. The system further includes circuitry generating a damping current, controlled by the controller, that reduces or eliminates reverberation of the transducer.

Abstract: An obstacle monitoring system includes a first transducer that obtains a first distance measurement to an obstacle using a first linear frequency modulated (“LFM”) chirp. The system further includes a second transducer, able to operate concurrently with the first transducer, that obtains a second distance measurement to the obstacle using a second LFM chirp. The second LFM chirp has an inverted slope or shifted center frequency compared to the first LFM chirp. The system further includes a controller that processes the first and second distance measurements to determine a motion-compensated distance measurement to the obstacle.

Abstract: An illustrative sensor controller embodiment includes: a transmitter that drives an ultrasonic transducer to produce a transmit pulse; a receiver that derives a sensor signal from the transducer; and a core logic that detects a trigger signal on an event signaling line and responsively provides one or more error reporting bits on the event signaling line before driving the event signaling line based on the sensor signal. An illustrative embodiment of a sensor control method includes: detecting a trigger signal on an event signaling line; providing at least one status bit on the event signaling line in response to the trigger signal; and after providing the at least one status bit, driving the event signaling line based upon on a sensor signal from a transducer. The transducer may be a piezoelectric element for producing and sensing ultrasonic pulses, particularly for use in parking-assist sensors and systems.

Abstract: In one form, an acoustic signal is generated for an acoustic transducer, where the acoustic transducer transmits the acoustic signal to determine a first position of an obstacle. In response to the acoustic signal encountering the obstacle within a predetermined distance, an echo, or pulse, is detected at the acoustic transducer. At a first time, a magnitude is detected in response to a rising edge of the pulse intersecting a determined threshold. A second magnitude is detected in response to the detection of a first peak of the pulse. A time of flight of the acoustic signal, within the predetermined distance, is determined when a compensation time is extracted from a correction calculation algorithm in response to detecting the first magnitude and the second magnitude. The compensation time is subtracted from the first time, and the difference of the compensation time and the first time is the time of flight.

Abstract: In one form, an acoustic signal is generated for an acoustic transducer, where the acoustic transducer is susceptible to reverberation that defines a close proximity indication zone. The start of a close proximity indication zone window is defined after the generation of the acoustic signal at a first time. During the close proximity indication zone window, a signal is received from the acoustic transducer. When the signal is received, an obstacle is detected in the close proximity indication zone if the magnitude of a first pulse received from the transducer at a second time is less than a first threshold but greater than a second threshold for a debounce time. Additionally, a magnitude of a second pulse received from the transducer outside the close proximity indication zone window at a third time should be less than the second threshold but greater than a third threshold for the debounce time.

Abstract: An illustrative sensor controller embodiment includes: a transmitter that drives an ultrasonic transducer to produce a transmit pulse; a receiver that derives a sensor signal from the transducer; and a core logic that detects a trigger signal on an event signaling line and responsively provides one or more error reporting bits on the event signaling line before driving the event signaling line based on the sensor signal. An illustrative embodiment of a sensor control method includes: detecting a trigger signal on an event signaling line; providing at least one status bit on the event signaling line in response to the trigger signal; and after providing the at least one status bit, driving the event signaling line based upon on a sensor signal from a transducer. The transducer may be a piezoelectric element for producing and sensing ultrasonic pulses, particularly for use in parking-assist sensors and systems.

Abstract: In one embodiment, a transducer controller is configured to form an integrated distance measuring and diagnostic cycle that includes measuring a decay time of a transducer and to selectively adjust a period of the transmitted signal responsively to a value of a reverberation period.

Abstract: In one embodiment, a transducer controller is configured to form an integrated distance measuring and diagnostic cycle that includes measuring a decay time of a transducer and to selectively adjust a period of the transmitted signal responsively to a value of a reverberation period.