Smartphone “Quick-Jack” Transforms Audio Jack Into Multipurpose Data Port
Adapting the standard 3.5-mm audio jack found on most iOS or Android smartphones, the Smartphone Quick-Jack Solution creates a universal interface for external sensors, switches, peripherals, and other devices. Simply, NXP’s kit turns the audio jack into a self-powered data port, offering a plug-and-go method to get data into myriad applications, such as control, monitoring, data collection, maintenance, and medical. The solution includes a circuit board based on an LPC812 MCU (ARM Cortex M0+), header for connecting an external debug probe, 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, and an energy-harvesting circuit that draws power from smartphone audio signals (via the right audio channel). In addition, an example app for Android phones and iPhones displays joystick position and temperature, and can turn Quick-Jack board devices on and off.