Archive for September 8th, 2009


Hardware Connectivity: H4I

Now here’s something a bit different for this neck of the woods: how to develop hardware iPhone products. Yes, indeed, hardware products … that do not use the ExternalAccessory framework for Apple-blessed accessory connectivity development:

Progical Solutions LLC is targeting an audience of iPhone professionals in the software and hardware industries currently unable to bring their accessories to market.

Now just how do they do that, one wonders? Well, get this, they turn the audio jack into a modem. Yes, a modem. Seriously.

The H4I program has evolved from the initial work done by Alex Winston. Although this work was groundbreaking at the time there wasn’t an easy way to support developers who might adopt this technology. However with the release of the iPhone SDK 3.0 Apple also released the External Accessory framework. With this framework as the model Progical Solutions LLC has implemented these interfaces as a standardized means to integrate apps with external accessories through the 3.5mm audio jack. At speeds up to 19.2K baud, serial data can be programmatically sent and received by the iPhone and iPod.

Must admit we’re not 100% clear on why exactly you’d want to go this route instead of through the official method; but hey, it’s an impressively geeky achievement nevertheless!

h/t: MobileOrchard!