Many app features depend on connectivity with external devices to collect readings from sensors, control switches, data collected by external meters, as well as act on user inputs from keyboard, wands, or joysticks and more. For these types of apps, tying up the phone's high-bandwidth USB/Lightning port is unnecessary.

While wireless connectivity offers user convenience; it can also increase BOM cost in small devices and requires experience working with wireless protocols, and an external power source. By repurposing the audio jack, the Smartphone Quick-Jack solution makes communication with external devices as easy as plugging in headphones.

"Smartphone user interfaces and connectivity features have revolutionized personal communication. The new Smartphone Quick-Jack Solution makes it exceptionally easy to take advantage of those same appealing features when designing end products, from something as sophisticated as a portable air-quality monitor, to something as rewarding as a child's toy with changeable/uploadable features," said Jim Trent, vice president and general manager, business line microcontrollers, NXP Semiconductors.

"We initially designed HiJack to create a universal way to connect low-cost sensor devices easily and securely to any brand of smartphone, tablet, or even PC," said Prabal Dutta, Assistant Professor, EECS , University of Michigan.

"Today, the applications for audio jack connectivity have exploded, from our original vision of low-cost measurement instruments, to mobile entertainment, secure card readers, remote controls, personal medical monitors and many more."

For end-product designers, the Smartphone Quick-Jack Solution puts appealing smartphone UI features at their fingertips for data display, controlling switches, monitoring sensors, collecting diagnostics and other field data. The phone's wireless connectivity supports data upload, storage, firmware updates, and general communication with the cloud, without the need to configure extra hardware or software.

For smartphone app developers, the solution provides plug-and-go data connectivity and power for external devices, making it simple to add sophisticated, user- or environment-aware inputs and features into smartphone apps. It also creates a secondary data/control channel for use when the USB/Lightning port is busy.

Features:

－ Circuit board based on an LPC812 MCU

－ Header for connecting external debug probe, enabling code development

－ Energy harvesting design draws power from smartphone audio signals

－ I/O devices: joystick, thermometer and LEDs

－ 3.5 mm male stereo plus microphone audio jack

－ Expansion connector for attaching external sensor/switch/HMI devices

－ Downloadable free Apps for both iOS and Android, source code included

－ Battery (optional)