Abstract: According to some aspects an electronic device adapted to detect whether it is coupled to an audio system. The electronic device includes a pulse generator adapted to generate a pulse on a ground return line of the electronic device, and a detector adapted to observe if a response signal is received by the electronic device corresponding to the pulse. If the response signal is received, the electronic device determined that it is coupled to the audio system.

Abstract: Various embodiments are described herein related to techniques for synchronizing a slave device to a master device that communicates using a unified bus communication protocol or some aspect thereof. In one example, the method may comprise assuming a first mode of operation for the unified bus communication protocol; searching for a synchronization pattern at one or more locations in transmitted data according to the first mode of operation; obtaining synchronization when the located synchronization pattern is verified according to at least one synchronization rule for the mode of operation; and if synchronization is not obtained based on the assumed first mode of operation, a second mode of operation for the unified bus communication protocol is assumed and the searching and obtaining acts are carried out on the transmitted data according to the second mode of operation.

Abstract: In use in a battery, a first spiral-wound battery element and associated wiring generates a first magnetic field and a second spiral-wound battery element and associated wiring generates a second magnetic field. The first element, the second element and the wiring may be arranged within a casing so that the first magnetic field is proximate to the second magnetic field and oriented in an opposite polarity. Conveniently, it may be shown that the total magnetic field generated by the battery has significantly lower magnitude than the total magnetic field generated by a conventional battery for the same current drain and same wiring structure.

Abstract: Embodiments are directed to receiving, by a microphone configured for audio use, an ultrasonic signal, applying an analog-to-digital (A/D) converter to the signal to generate a digital version of the signal, obtaining phase information from the digital version of the signal, and determining a position of an emitter of the ultrasonic signal based on the phase information.

Abstract: Various embodiments are described herein for a multiformat communication protocol that may be used to tunnel messages suitable for a second communication protocol. The multiformat communication protocol may be used by an intermediate device to couple a bus that communicates according to the multiformat communication protocol with a bus that communicates according to the second communication protocol.

Abstract: A method for identifying an accessory coupled to an electronic device. The method includes applying at least one detection pulse to the audio accessory, each detection pulse being spectrally shaped to be generally inaudible to a human user, receiving at least one response signal corresponding to each detection pulse that is indicative of the impedance of the accessory, and based on the impedance, identifying the accessory.

Abstract: According to one aspect, an electronic device adapted to be controlled by an audio accessory. The electronic device includes at least one resonator. Each resonator is tuned to respond to a particular frequency that corresponds to a particular message generated by the audio accessory. When the particular message is received, the corresponding resonator resonates to generate an output signal that controls the electronic device.

Abstract: An audio system including a first audio unit and a second audio unit coupled to the first audio unit through an audio bus. A first processor is coupled to the first audio unit. The first processor is configured to transmit bits comprising audio content to the second audio unit over the audio bus. The first processor is further configured to receive a control command selected from a plurality of control commands, and in response, interrupt the bits comprising audio content and send a preamble and a control message on the audio bus, wherein the control message corresponds to the control command. A second processor is coupled to the second audio unit. The second processor is configured to monitor the audio bus for a preamble, and if a preamble is detected, then process the control message and execute the corresponding control command.

Abstract: The present disclosure provides a method of determining microphone polarity in a headset. By being able to detect the polarity of the microphone within the headset, a portable electronic device may be compatible with any headset and is not limited to use with a specific headset. By applying a detection signal over one of lines within a headset cable, a return signal may be sensed on one of the other lines to determine which of the lines is the ground line and which line is the microphone line.

Abstract: A circuit, device and method for controlling an output signal of an amplifier are provided. The output signal may be controlled through a first stage located before a digital to analog converter and/or a second stage located after it. The first stage boosts the digital signal to match with the full signal range of the converter. For the second stage, the circuit comprises: a first resistor coupled to an output of the amplifier in series, the first resistor having a resistance value Rs; a second resistor coupled to the first resistor in series, the second resistor having a resistance value Rp; and an output terminal for a transducer connected to the electronic device, the output terminal connected in parallel to the second resistor. In the circuit, the resistance values Rs and Rp are related by an inversely proportional relationship.

Abstract: A system for controlling an electronic device, including an accessory coupled to the device having a control interface for receiving at least one input and a tone generator, the accessory configured to, in response to an input, generate a corresponding control tone using the tone generator, and send the control tone and a calibration sequence to the device. The device is operable to receive the calibration sequence and control tone. The device includes a zero-crossing detector operable to determine at least one of the start or ending of each of the calibration sequence and the control tone and having a circuit operable to determine the periods of the calibration sequence and the control tone based on the zero-crossing detector output.

Abstract: A mobile wireless communications device may include a housing, and circuitry carried by the housing. The circuitry may include a wireless transceiver, a wireless broadcast receiver, audio circuitry coupled to the wireless transceiver and the wireless broadcast receiver, a wired headset jack, and a reference voltage device line, and at least one wired headset device line coupled between the audio circuitry and the wired headset jack. The reference voltage device line may be also coupled to the wireless broadcast receiver so that a corresponding reference voltage headset line of a wired headset serves as an antenna for the wireless broadcast receiver. The reference voltage line may be switchable to one or more connectors at the headset jack.

Abstract: According to some aspects, a system for controlling an electronic device including an audio accessory coupled to the electronic device. The audio accessory has at least one speaker adapted to provide audio output and a plurality of resistive switches. The electronic device has a bias voltage source adapted to provide power to the resistive switches via a bias resistor and a ground connection, and a measurement module. The measurement module is adapted to monitor a bias point to determine which of the at least one switch has been engaged based on effect of the resistive switches on the ground offset voltage after compensating for a ground offset voltage caused by the audio output.

Abstract: Embodiments are directed to receiving, by a microphone configured for audio use, an ultrasonic signal, applying an analog-to-digital (A/D) converter to the signal to generate a digital version of the signal, obtaining phase information from the digital version of the signal, and determining a position of an emitter of the ultrasonic signal based on the phase information.

Abstract: There is provided a single wire bus architecture comprising a single wire bus; a master device coupled to the single wire bus; at least one slave device coupled to the single wire bus; a communication protocol implemented over the single wire bus and employed by the master device and the at least one slave device; wherein when one of the at least one slave devices wishes to communicate with the master device, the one of the at least one slave devices discharges the clock signal during a tri-state stage of the clock signal; and wherein the single wire bus transmits a clock signal, power and data between the master device and the one of the at least one slave device in communication with the master device.

Abstract: A mobile device includes at least one speaker and an audio subsystem for providing an audio signal to the at least one speaker for playback by the at least one speaker. The audio subsystem operates by detecting a distance to a user of the mobile device using a proximity sensor and controlling volume output of the at least one speaker based on the distance to the user of the mobile device and the operational status of the proximity sensor. If it is determined that the proximity sensor is functional, the audio subsystem applies a gain factor to the audio signal that varies based on the distance to the user or limits the maximum allowable speaker output based on the distance. A high or low gain setting may be applied for when the user is far away or in close proximity to the mobile device.

Abstract: A low-noise pre-amplifier with an active load element is integrated into a microphone. The microphone has an acoustic sensor coupled to the intrinsic pre-amplifier. A controllable current source is coupled to the intrinsic pre-amplifier and supplies a pre-amplifier bias current. A current source controller is coupled to the current source and controls the amplitude of the pre-amplifier bias current to maintain the intrinsic pre-amplifier at a bias point at which the intrinsic pre-amplifier amplifies microphone signals produced by the acoustic sensor. The intrinsic pre-amplifier may be actively regulated at the pre-determined bias point using negative feedback. Alternatively, the intrinsic pre-amplifier may be set to the pre-determined bias point by sweeping the pre-amplifier bias current for the intrinsic pre-amplifier over a range of currents.

Abstract: Embodiments of various methods, devices and systems are described herein that correspond to an encoding scheme that can be used with various communication protocols for increased bandwidth over a single wire bus or a wireless single transmission channel. For example, a method of encoding a series of data bits to increase bandwidth may comprise selecting a data bit in the series of data bits, generating an inverted version of the selected data bit, positioning the inverted version of the selected data bit in a consecutive fashion with respect to the selected data bit to signify an edge of a clock signal, and transmitting the inverted version of the selected data bit and the series of data bits with each bit being transmitted in a single unique time slot.

Abstract: The embodiments described herein are directed to systems and methods for transmitting audio data and control segment in a single bitstream and reducing audio disturbance associated with the control segment when the bitstream is processed by an audio digital-to-analog converter. The system, according to one aspect, comprises a first audio unit, a transmitter coupled to the first audio unit, a receiver coupled to the transmitter, a second audio unit coupled to the receiver, a first processor coupled to at least one of the first audio unit and the transmitter, a second processor coupled to the second audio unit and the receiver, and an audio digital-to-analog converter connected to the second processor.

Abstract: According to one aspect, an electronic device adapted to be controlled by an audio accessory. The electronic device includes at least one resonator. Each resonator is tuned to respond to a particular frequency that corresponds to a particular message generated by the audio accessory. When the particular message is received, the corresponding resonator resonates to generate an output signal that controls the electronic device.