Direction data not available with U2 chip (iPhone 15 Pro and iPhone 16 Pro) when using Murata SR040/SR150 accessory

Hello,

I am developing with the Nearby Interaction framework using third-party UWB accessories (Murata SR040/SR150). I observed a difference between U1-based and U2-based iPhones:

iPhone 12 Pro (U1 chip)

NINearbyObject.direction returns valid 3D vector (x, y, z).

Distance and direction both work as expected.

iPhone 15 Pro and iPhone 16 Pro (U2 chip)

NINearbyObject.direction is always nil.

Only distance is returned (around 0.35–0.40 m in my test).

Effectively behaves as "distance-only mode".

Environment:

Hardware: iPhone 12 Pro, iPhone 15 Pro

iOS version: 18.5

Accessory: Murata UWB SR040 / SR150

App: Using NINearbyAccessoryConfiguration with BLE-based discovery

Info.plist includes NSNearbyInteractionUsageDescription

Camera assistance was tested both ON and OFF

Expectation: I expected the U2 chip to behave consistently with U1, i.e. provide direction vectors when possible. Instead, on iPhone 15 Pro, direction is always unavailable (nil) while distance is returned correctly.

Questions:

Is this an intentional limitation for U2 chip + third-party accessories?

Is there a new requirement (e.g. certification, firmware update, capability flags) to enable direction on U2 devices?

Could this be related to NIDeviceCapability or the new Extended Distance Measurement (EDM) mode in U2?

Thanks in advance for any clarification.

Direction data not available with U2 chip (iPhone 15 Pro and iPhone 16 Pro) when using Murata SR040/SR150 accessory
 
 
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