Creating accessories that use Apple’s proprietary dock connector isn’t the cheapest thing to do and some companies get around it by using the 3.5mm headset jack, such as Square. Now the folks over at the University of Michigan have been busy with Project HiJack that allows devices to draw 7.4mW out of a 22kHz audio tone. They have already managed to create prototype boards that transmit data to and from an iOS app using the headset jack and it only needed $2.34 worth of components.
The current boards include a working EKG, temperature, humidity, and also motion sensors, so it’s not like were talking about useless items here. Once the code is released with an open source license, hopefully we’ll see an influx of devices that use the 3.5mm jack instead of just headphones. Video is available after the jump.
