App note: NXP Smartphone Quick-Jack Solution


An interesting app note (PDF) from NXP where you can interface your mobile phone with a microcontroller via the audio 3.5mm jack.

Inspired by the University of Michigan’s Project HiJack, the NXP Smartphone Quick-Jack Solution repurposes the standard 3.5mm stereo audio jack found on most smartphones into a self-powered data channel that makes communication with these smartphones as easy as plugging a headset jack into the audio port.
The Quick-Jack demo board integrates a joystick, temperature sensor, LEDs and an expansion header. The app running on the smartphone is able to interface with these on-board peripherals via the Quick-Jack interface.

Join the Conversation


  1. And all of this hassle only because the major smartphone manufacturers are too dumb to agree on a common docking interface…

    1. If you look closely at the diagram, it has nothing to do with docking interfaces at all…

      I’m sure smartphone manufacturers are not dumb. Pretty sure they’ve studied their consumer psychology stuff. Turn everything into compatible commodity parts? Just like the PC business, how’s it doing now? Of course not.

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.