A sensing system generates location signals indicative of where an electrically-powered, mobile device is in a venue. A control system determines that the mobile device is at rest when the location signals are substantially the same for a predetermined period of time, processes the location signals to determine an accurate, current location of the mobile device in the venue when the mobile device is determined to be at rest, and controls the mobile device when determined to be at rest to operate in a low power mode in which the average electrical power consumption of the mobile device is reduced.

A sensing system generates location signals indicative of where an electrically-powered, mobile device is in a venue. A control system determines that the mobile device is at rest when the location signals are substantially the same for a predetermined period of time, processes the location signals to determine an accurate, current location of the mobile device in the venue when the mobile device is determined to be at rest, and controls the mobile device when determined to be at rest to operate in a low power mode in which the average electrical power consumption of the mobile device is reduced.

A detection and transmission system includes a first detection and transmission device and a second detection and transmission device. The second detection and transmission device is disposed in a first direction from the first detection and transmission device. The first detection and transmission device generates a first sound signal toward the first direction when detecting a first moving object. The second detection and transmission device generates a second sound signal when receiving the first sound signal.

A detection and transmission system includes a first detection and transmission device and a second detection and transmission device. The second detection and transmission device is disposed in a first direction from the first detection and transmission device. The first detection and transmission device generates a first sound signal toward the first direction when detecting a first moving object. The second detection and transmission device generates a second sound signal when receiving the first sound signal.

Systems, devices and methods are provided for multi-device interactions. For example, a transmitting device detects a media content control command input by a user for operation of a first application client, wherein the media content control command includes media content identification; the transmitting device encodes the media content control command into an audio identifier string; and the transmitting device transmits the audio identifier string through first sound waves. A receiving device is configured to detect the first sound waves using a second application client, extract the audio identifier string from the first sound waves, decode the audio identifier string to acquire the media content control command, and operate on first media content corresponding to the media content identification included in the media content control command.

Systems, devices and methods are provided for multi-device interactions. For example, a transmitting device detects a media content control command input by a user for operation of a first application client, wherein the media content control command includes media content identification; the transmitting device encodes the media content control command into an audio identifier string; and the transmitting device transmits the audio identifier string through first sound waves. A receiving device is configured to detect the first sound waves using a second application client, extract the audio identifier string from the first sound waves, decode the audio identifier string to acquire the media content control command, and operate on first media content corresponding to the media content identification included in the media content control command.

A method of operating an acoustic system includes detecting an ultrasonic sound signal and pattern matching the received ultrasonic sound signal to determine when the received ultrasonic sound signal is a desired ultrasonic sound signal. The method includes sending a signal to at least one electronic component when the received ultrasonic sound signal is the desired ultrasonic sound signal. The method includes operating the microphone in a lower power state when the received ultrasonic sound signal is not the desired ultrasonic sound signal.

A method of operating an acoustic system includes detecting an ultrasonic sound signal and pattern matching the received ultrasonic sound signal to determine when the received ultrasonic sound signal is a desired ultrasonic sound signal. The method includes sending a signal to at least one electronic component when the received ultrasonic sound signal is the desired ultrasonic sound signal. The method includes operating the microphone in a lower power state when the received ultrasonic sound signal is not the desired ultrasonic sound signal.

Methods, apparatus, and systems provide wireless remote control of firearm accessories using ultrasonic communication through air. In some variations a transmitter and a receiver used in these methods, apparatus, and systems need not be in line-of-sight, so the location of the accessory on the firearm may be selected independently of the location of remote controls for the accessory. The firearm accessories may be or include, for example, laser pointers and illuminators.

Methods, apparatus, and systems provide wireless remote control of firearm accessories using ultrasonic communication through air. In some variations a transmitter and a receiver used in these methods, apparatus, and systems need not be in line-of-sight, so the location of the accessory on the firearm may be selected independently of the location of remote controls for the accessory. The firearm accessories may be or include, for example, laser pointers and illuminators.