Hardware Hacking for iOS Programmers via Tom.
The arrival of the External Accessory Framework was seen, initially at least, as having the potential to open the iOS platform up to a host of external accessories and additional sensors. Sadly, little of the innovation people were expecting actually occurred, and while there are finally starting to be some interesting products arriving on the market, for the most part the External Accessory Framework is being used to support a fairly predictable range of audio and video accessories from big-name manufacturers.
The reason for this lack of innovation is usually laid at the feet of Apple’s Made for iPod (MFi) licensing program. To develop hardware accessories that connect to the iPod, iPhone, or iPad, you must be an MFi licensee.