As part of WWDC this week, Apple has released a draft specification of its Nearby Interaction Accessory Protocol, allowing third-party accessory manufacturers to review preliminary hardware and software requirements for developing accessories that interact with the U1 chip in supported Apple devices, like iPhone 11 and iPhone 12 models.
Third-party accessories that are designed to be interoperable with the U1 chip will be able to provide precise and directionally-aware experiences, just like Apple accessories can. For example, users can bring a U1-equipped iPhone close to a HomePod mini to hand off music playback, complete with visual, audible, and haptic effects, or access a Precision Finding feature when an AirTag is near a U1-equipped iPhone.
NXP Semiconductors and Qorvo are now offering development kits for designing third-party accessories that are interoperable with the U1 chip. However, it's unclear when the first U1-enabled third-party accessories will be released.
Apple first opened up the U1 chip to app developers with the release of the Nearby Interaction framework at WWDC 2020, allowing for precise, directionally aware app experiences, and now it is expanding this Ultra Wideband integration to hardware accessories. Apple has a WWDC 2021 session on the topic with more details.
