Abstract: A batteryless wireless sensor system includes a data acquisition system, a radio frequency (RF) transceiver, and a batteryless wireless sensor device. The RF transceiver is in communication with the data acquisition system, transmits a RF signal, and receives sensor data and provide the sensor data to the data acquisition system. The batteryless wireless sensor device includes a RF transmitter, an analog to digital converter (ADC), and a sensor. The batteryless wireless sensor harvests energy from the RF signal and generates a DC signal based on the energy harvested from the RF signal, powers up and operates the ADC and the sensor based on the DC signal, and generates sensor data. The batteryless wireless sensor then transmits the sensor data via the RF transmitter to the RF transceiver. In certain examples, the ADC is implemented as a current mode ADC.

Abstract: An analog to digital converter (ADC) that is configured to service a photo-diode includes a capacitor and a self-referenced latched comparator. The capacitor produces a photo-diode voltage based on charging by a photo-diode current associated with the photo-diode and a digital to analog converter (DAC) source current and/or a DAC sink current. The self-referenced latched comparator generates a first digital signal that is based on a difference between the photo-diode voltage and a threshold voltage associated with the self-referenced latched comparator. Also, one or more processing modules executes operational instructions to process the first digital signal to generate a second digital signal and/or a third digital signal. An N-bit DAC generates the DAC source current based on the second digital signal, and an M-bit DAC generates the DAC sink current based on the third digital signal. The DAC source current and/or the DAC sink current tracks the photo-diode current.

Abstract: A test strip for sampling a bodily fluid may include multiple layers of a substrate material, an adhesive between at least some of the multiple layers, and a microfluidic channel formed between at least some of the multiple layers. The test strip may further include multiple electrodes on one of the multiple layers, positioned and partially exposed within the microfluidic channel, an additional material positioned at or near an entrance to the microfluidic channel, to selectively limit the flow of at least one of bubbles or debris into the microfluidic channel, and at least one exit port in at least one of the multiple layers to allow for release of pressure from the test strip. In some embodiments, the test strip is a saliva analysis test strip. In some embodiments, the test strip includes multiple exit ports to prevent blockage of sample flow.

Abstract: A noise canceling audio in/out device includes an audible in/out transducer operable to convert an audible noise signal to a noise signal and convert an audio transmit (TX) signal to an audible output signal. A transducer signal of the audible in/out transducer generated by the audio TX signal is affected by the noise signal. The noise canceling audio in/out device further includes a noise canceling circuit operable to convert a digital TX signal to a TX reference signal, compare the transducer signal with the TX reference signal to produce an analog comparison signal, where the analog comparison signal includes a representation of the audio TX signal and the noise signal, and regulate the transducer signal to substantially match the TX reference signal to remove the effect of the noise signal on the transducer signal.

Abstract: A batteryless wireless sensor system includes a data acquisition system, a radio frequency (RF) transceiver, and a batteryless wireless sensor device. The RF transceiver is in communication with the data acquisition system, transmits a RF signal, and receives sensor data and provide the sensor data to the data acquisition system. The batteryless wireless sensor device includes a RF transmitter, an analog to digital converter (ADC), and a sensor. The batteryless wireless sensor harvests energy from the RF signal and generates a DC signal based on the energy harvested from the RF signal, powers up and operates the ADC and the sensor based on the DC signal, and generates sensor data. The batteryless wireless sensor then transmits the sensor data via the RF transmitter to the RF transceiver. In certain examples, the ADC is implemented as a current mode ADC.

Abstract: A batteryless wireless sensor system includes a data acquisition system, a radio frequency (RF) transceiver, and a batteryless wireless sensor device. The RF transceiver is in communication with the data acquisition system, transmits a RF signal, and receives sensor data and provide the sensor data to the data acquisition system. The batteryless wireless sensor device includes a RF transmitter, an analog to digital converter (ADC), and a sensor. The batteryless wireless sensor harvests energy from the RF signal and generates a DC signal based on the energy harvested from the RF signal, powers up and operates the ADC and the sensor based on the DC signal, and generates sensor data. The batteryless wireless sensor then transmits the sensor data via the RF transmitter to the RF transceiver. In certain examples, the ADC is implemented as a current mode ADC.

Abstract: An analog to digital converter (ADC) senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. The digital output signal provided to the N-bit DAC is an inverse function of the load current. The ADC is operative to sense very low currents (e.g., currents as low as is of pico-amps) and consume very little power (e.g., less than 2 ?W).

Abstract: A device operative to transfer power wirelessly includes a drive-sense circuit (DSC), memory that stores operational instructions, and processing module(s). The DSC generates a drive signal based on a reference signal and provides the drive signal to a first coil via a single line and via a resonating capacitor, and simultaneously senses the drive signal via the single line, to facilitate electromagnetic coupling to a second coil to transfer power wirelessly to another device. The DSC also detects electrical characteristic(s) of the drive signal. The processing module(s) generates the reference signal and processes the digital signal to determine the electrical characteristic(s) of the drive signal. In some examples, the processing module(s) adapts the reference signal based on detection of the other device (e.g., based on interpreting the electrical characteristic(s) of the drive signal).

Abstract: A current reference operative drive-sense circuit (DSC) includes a current source operably coupled to a load and a voltage-mode analog to digital converter (ADC). When enabled, the current source is configured to drive a sinusoidal current reference signal to the load thereby generating a load voltage that is based on the sinusoidal current reference signal and an impedance of the load. The voltage-mode ADC is operably coupled the load and to the current source. When enabled, the voltage-mode ADC configured to perform digital sampling of the load voltage and to generate a digital signal that is representative of the load voltage. In some implementations, one or more processing modules is configured to execute operational instructions to process the digital signal that is representative of the load voltage in accordance with determining impedance of the load and/or change of impedance of the load.

Abstract: A device operative to transfer power wirelessly includes a drive-sense circuit (DSC), memory that stores operational instructions, and processing module(s). The DSC generates a drive signal based on a reference signal and provides the drive signal to a first coil via a single line and via a resonating capacitor, and simultaneously senses the drive signal via the single line, to facilitate electromagnetic coupling to a second coil to transfer power wirelessly to another device. The DSC also detects electrical characteristic(s) of the drive signal. The processing module(s) generates the reference signal and processes the digital signal to determine the electrical characteristic(s) of the drive signal. In some examples, the processing module(s) adapts the reference signal based on detection of the other device (e.g., based on interpreting the electrical characteristic(s) of the drive signal).

Abstract: An analog to digital converter (ADC) that is configured to service a photo-diode includes a capacitor and a self-referenced latched comparator. The capacitor produces a photo-diode voltage based on charging by a photo-diode current associated with the photo-diode and a digital to analog converter (DAC) source current and/or a DAC sink current. The self-referenced latched comparator generates a first digital signal that is based on a difference between the photo-diode voltage and a threshold voltage associated with the self-referenced latched comparator. Also, one or more processing modules executes operational instructions to process the first digital signal to generate a second digital signal and/or a third digital signal. An N-bit DAC generates the DAC source current based on the second digital signal, and an M-bit DAC generates the DAC sink current based on the third digital signal. The DAC source current and/or the DAC sink current tracks the photo-diode current.

Abstract: A device operative to transfer power wirelessly includes a drive-sense circuit (DSC), memory that stores operational instructions, and processing module(s). The DSC generates a drive signal based on a reference signal and provides the drive signal to a first coil via a single line and via a resonating capacitor, and simultaneously senses the drive signal via the single line, to facilitate electromagnetic coupling to a second coil to transfer power wirelessly to another device. The DSC also detects electrical characteristic(s) of the drive signal. The processing module(s) generates the reference signal and processes the digital signal to determine the electrical characteristic(s) of the drive signal. In some examples, the processing module(s) adapts the reference signal based on detection of the other device (e.g., based on interpreting the electrical characteristic(s) of the drive signal).

Abstract: A test system includes a test container array including a plurality of test containers and a plurality of electrodes integrated into the test container array. The test system further includes a plurality of drive-sense circuits coupled to the plurality of electrodes, where, when enabled, the plurality of drive-sense circuits detect changes in electrical characteristics of the plurality of electrodes. The test system further includes a processing module operably coupled to receive, from the drive-sense circuits, changes in the electrical characteristics of the plurality of electrodes, and interpret the changes in the electrical characteristics of the plurality of electrodes as impedance values representative of electrical characteristics of biological material present in the test container. The test system further includes a communication module operably coupled to communicate the electrical characteristics of the biological material.

Abstract: A device operative to transfer power and communicate wirelessly includes a drive-sense circuit (DSC), memory that stores operational instructions, and processing module(s). The DSC generates a drive signal based on a reference signal and provides the drive signal to a first coil via a single line and via a resonating capacitor, and simultaneously senses the drive signal via the single line, to facilitate electromagnetic coupling to a second coil to transfer power wirelessly to another device. The DSC also detects electrical characteristic(s) of the drive signal including whether a communication signal is transmitted from another device and generates a digital signal representative thereof.

Abstract: A test system includes a testing base including a plurality of testing base containers, and a plurality of electrodes integrated into the plurality of testing base containers. The test system further includes a plurality of drive-sense circuits coupled to the plurality of electrodes, where, when enabled, the plurality of drive-sense circuits detect changes in electrical characteristics of the plurality of electrodes. The test system further includes a processing module operably coupled to receive, from the drive-sense circuits, changes in the electrical characteristics of the plurality of electrodes, and interpret the changes in the electrical characteristics of the plurality of electrodes as impedance values representative of electrical characteristics of biological material present in the test container. The test system further includes a communication module operably coupled to communicate the electrical characteristics of the biological material.

Abstract: A current reference operative drive-sense circuit (DSC) includes a current source operably coupled to a load and a voltage-mode analog to digital converter (ADC). When enabled, the current source configured to drive a sinusoidal current reference signal to the load thereby generating a load voltage that is based on the sinusoidal current reference signal and an impedance of the load. The voltage-mode ADC is operably coupled the load and to the current source. When enabled, the voltage-mode ADC configured to perform digital sampling of the load voltage and to generate a digital signal that is representative of the load voltage. In some implementations, one or more processing modules configured to execute operational instructions to process the digital signal that is representative of the load voltage in accordance with determining impedance of the load and/or change of impedance of the load.

Abstract: An impedance sensing circuit includes first and second current sources and first and second bias current sources that are appropriately coupled to first and second resistors. The impedance sensing circuit also includes a comparator that compares a first voltage based on the first terminal of the first resistor to a second voltage based on the first terminal of the second resistor to generate a comparator output signal. Either the comparator output signal or a digital signal based on the comparator output signal operates to regulate the current signals output from the first and second current sources so that the first voltage is same as the second voltage. The comparator output signal and the digital signal is representative of a difference between the first voltage and the second voltage that is based on an impedance difference between the first resistor and the second resistor.

Abstract: An analog to digital converter (ADC) senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. The digital output signal provided to the N-bit DAC is an inverse function of the load current. The ADC is operative to sense very low currents (e.g., currents as low as is of pico-amps) and consume very little power (e.g., less than 2 ?W).

Abstract: Techniques for updating blockchains using a proof of work determined serially include receiving a block of data for inclusion in a new block of a blockchain; deterministically determining an initial nonce, hashing a combination of the block of data and the initial nonce to create a hashed value; iteratively deterministically determining an updated nonce based on a combination of the hashed value and updating the hashed value by hashing the updated nonce until the updated hashed value satisfies a proof of work criteria; creating the new block based on the block of data, the initial nonce, and the updated hashed value that satisfies the proof of work criteria; and having the new block stored in the blockchain.

Abstract: A channel driver circuit includes a differential module and a driver module. In some examples, the channel driver circuit also includes a sigma-delta module. The differential module receives, via a single node of a load, a channel driving signal that is provided to the load at the single node (e.g., that is based on an electrical characteristic of the load) and generates an analog error signal that is based on the channel driving signal and a reference signal. The driver module is coupled to the differential module and generates the channel driving signal based on the analog error signal or a digital error signal corresponding to the analog error signal and transmits the channel driving signal via the single node to the load. The channel driver circuit simultaneously transmits the channel driving signal to the load at the single node and senses the channel driving signal at the single node.