Abstract: A device is described for establishing communication between a first device and a second device. In one implementation, a first internal interface of the first device couples to a first external interface of the second device while a second internal interface of the first device couples to a second external interface of the second device. A first unidirectional data channel may be opened for incoming data using the first internal interface. A second unidirectional data channel may be opened for outgoing data using the second internal interface. The pair of unidirectional data channels is established, allowing data transfer between the devices. These channels allow for asynchronous-like transmission of data, in that transmission and corresponding receipt of data may take place at irregular intervals.

Abstract: A signal is provided in response to moving contact of a device with an object. Electronic circuitry transitions from an inactive state to an active state in response to the signal and scans a machine-readable code borne by the object. A data signal including or encoding the machine-readable code is provided. The electronic circuitry may transition from the active state back to the inactive state after the data signal has been provided and the present code scanning operation is complete. Power consumption by code scanner devices, user input stylus, or other apparatus is reduced accordingly.

Abstract: Audio data and video data are processed to determine one or more audible events and visual events, respectively. Contemporaneous presentation of the video data with audio data may be synchronized based at least in part on the audible events and the visual events. Audio processing functions, such as filtering, may be initiated for audio data based at least in part on the visual events.

Abstract: Synchronous interfaces on a first device are configured such that a first synchronous interface is set to a slave mode while a second synchronous interface is set to a master mode. A second device with two synchronous interfaces may then be coupled to the first device with the corresponding synchronous interfaces in master mode and slave mode, respectively. A pair of unidirectional synchronous data channels is established, allowing data transfer between the devices. These channels allow for asynchronous-like transmission of data, in that transmission and corresponding receipt of data may take place at irregular intervals.