A team at the University of Michigan has been developing a project, titled "HiJack
" to help make basic data peripherals for the iPhone, iPod touch, and iPad without hefty fees. By using the audio jack on the device to both power the sensor and transmit data, smaller manufacturers, research teams, or even individuals are able to develop fairly creative add-ons for devices.
Very often, a significant part of the cost of designing an iOS data sensor comes from the right to use the familiar "Made for iPhone/iPad/iPad
" logo on the sensor's box, and also allows the designer access to the 30-pin connector. Project HiJack is both a hardware a software platform that does not require the need for this labeling, because it does not use Apple's proprietary 30 pin connector.
, writing about HiJack, states "the system uses the 22kHz audio signal, which is converted into 7.4mW of power." In other words, enough to power a variety of devices, and allowing these sensors to communicate with a specifically designed iOS application.
We've already seen this power conversion used before, for instance in the Square
sensor that allows an iOS device to be used as a point of sale and a credit card reader. HiJack's aspirations push this even further. The team states that sensors could be built for "as little as $2.34 in significant quantities."
The project has allowed research groups to create a variety of data acquisition sensors already, including an EKG interface and a temperature/humidity sensor. The team also is intent on spreading this technology to the masses, by posting the schematics and source code to Google Code
, and by announcing their intention to port the software to more platforms such as Android and WP7.
If you've got a lazy Sunday planned and you've got some soldering skills, HiJack very well may be right up your alley. It will be very interesting to see what kind of sensors can be created to enhance the iOS and mobile device experience.