Nordic iOS DFU Library

NordicDFU is a Swift library designed to update the firmware of nRF51 and nRF52 devices over Bluetooth LE. It supports devices running nRF5 SDK (version 4.3 and later).

Key Capabilities:

• Update Application, SoftDevice, and/or Bootloader Over-the-Air (OTA).
• Support for ZIP, HEX, or BIN file formats.
• Handle bonded devices and buttonless updates.
• Built-in recovery mechanisms for communication errors.

Important Compatibility Note: This library is not compatible with the MCU Manager subsystem from nRF Connect SDK (NCS) or Zephyr. For those SDKs, use the nRF Connect Device Manager library instead.

For DFU to work correctly with iOS, the target device MUST have the Service Changed characteristic with the Indicate property in the Generic Attribute service.

Without this characteristic, iOS will not invalidate its service cache when the device switches to DFU bootloader mode, which can prevent the update from succeeding.

Behavioral details:

• Paired devices: iOS automatically handles the indication to the Service Changed characteristic to perform service discovery. This is supported in Legacy DFU since SDK 8.0.
• Non-trusted (unpaired) devices: iOS clears the service cache every time the device disconnects.

The library is fully backwards compatible and supports both Legacy DFU and Secure DFU.

• Legacy DFU: Supports application updates (SDK 4.3.0) and combined SoftDevice/Bootloader updates (SDK 6.1.0).
• Secure DFU: Introduced in SDK 12.0.0.

Note on Experimental Buttonless Service: The experimental buttonless service from SDK 12 is supported since library version 1.1.0. Because this service is considered unsafe, it is disabled by default. To enable it, you must set enableUnsafeExperimentalButtonlessServiceInSecureDfu to true. It is recommended to use the Buttonless service from SDK 13 (for non-bonded devices) or SDK 14 (for bonded devices) instead.

The DFUState enumeration represents the various stages of the Device Firmware Update process. You can use these states to update your application's UI, track progress, or respond to specific lifecycle events (such as success, failure, or cancellation).

The available states are:

• connecting: The library is attempting to establish a connection with the device.
• starting: The DFU process is being initialized.
• enablingDfuMode: The device is being transitioned into DFU mode.
• uploading: Firmware data is currently being transferred to the device.
• validating: The device is verifying the integrity of the uploaded firmware.
• disconnecting: The library is cleaning up the connection.
• completed: The update finished successfully.
• aborted: The update process was cancelled or failed to start.

The library is designed for performing Device Firmware Updates on nRF5x Series devices. Specifically, it requires:

• nRF51 or nRF52 devices.
• An S-Series SoftDevice flashed on the device.
• A DFU Bootloader flashed on the device.

All Archive operations accept an optional progress parameter of type Progress.

• Tracking: ZIP Foundation automatically manages totalUnitCount and updates completedUnitCount. You can observe the fractionCompleted property using a Key-Value Observer (KVO) to get updates.
• Cancellation: Call cancel() on the Progress instance to terminate an ongoing operation. If cancelled, the operation will throw an ArchiveError.cancelledOperation error.

To build a responsive UI and debug the update process, you should implement the following delegates on your DFUServiceInitiator:

• DFUProgressDelegate: Use this to receive updates on the current progress of the firmware upload.
• LoggerDelegate: Use this to receive log information via the logger property. This is useful for tracking the internal state and troubleshooting communication issues.
• DFUServiceDelegate: Use this to be informed about the overall DFU state changes and any errors that occur during the process.

To install using Carthage, add the repository to your Cartfile. Build the dependencies using the carthage update command with the --use-xcframeworks flag. This will produce NordicDFU.framework and ZipFramework.framework in the Carthage/Build/ directory, which you should then copy into your project.

github "NordicSemiconductor/IOS-DFU-Library" ~> x.y // Replace x.y with your required version

carthage update --use-xcframeworks --platform iOS

To add ZIPFoundation to your project using Swift Package Manager, add the dependency to your Package.swift file and include it in your target's dependencies. After updating the file, run swift package resolve to fetch the library.

// swift-tools-version:5.0
import PackageDescription
let package = Package(
    name: "<Your Product Name>",
    dependencies: [
		.package(url: "https://github.com/weichsel/ZIPFoundation.git", .upToNextMajor(from: "0.9.0"))
    ],
    targets: [
        .target(
		name: "<Your Target Name>",
		dependencies: ["ZIPFoundation"]),
    ]
)

$ swift package resolve