原创 Hugging Face 2024-11-21 15:01 美国
开源可穿戴设备来啦！
在飞速发展的可穿戴技术领域，我们正处于一个十字路口——市场上充斥着各式时尚、功能丰富的设备，声称能够彻底改变我们对健康和健身的方式。
然而，在这些光鲜的外观和营销宣传背后，隐藏着一个令人担忧的现实：大多数这些设备是封闭系统，其内部运行被专有代码和封闭硬件所掩盖。作为消费者，我们对这些设备如何收集、处理及可能共享我们的健康数据一无所知。
这时，Halo 出现了，它是一种旨在让健康追踪更加普惠化的开源替代方案。通过这系列文章，我们将引导你从基础入手，构建并使用完全透明、可定制的可穿戴设备。
需要说明的是，Halo 的目标并不是在外观或功能完整性上与消费级可穿戴设备竞争。相反，它提供了一种独特的、动手实践的方式来理解健康追踪设备背后的技术。
我们将使用 Swift 5 来构建对应的 iOS 界面，Python >= 3.10。由于此项目的代码完全
你将需要：
获取
一个安装了 Xcode 16 的开发环境，以及可选的 Apple 开发者计划会员资格。
Python >= 3.10，并安装了 pandas、numpy、torch 当然还有 transformers。
致谢
此项目基于
免责声明
作为一名医生，我有法律义务提醒你：你即将阅读的内容并不是医学建议。现在，让我们开始让一些可穿戴设备发出蜂鸣声吧！
配对戒指
在进入代码之前，让我们先了解蓝牙低能耗 (BLE) 的关键规格。BLE 基于一个简单的客户端-服务器模型，使用三个核心概念：中央设备 (Centrals) 、服务 (Services) 和 **特征 (Characteristics)**。以下是它们的具体介绍：
中央设备 (例如你的 iPhone) 负责启动和管理与外设 (例如我们的 COLMI R02 戒指) 的连接。戒指通过广播自身信息等待手机连接，每次仅支持一台手机连接。
服务 是戒指上相关功能的集合，例如心率监测服务或电池状态服务。每个服务都有一个唯一标识符 (UUID) ，客户端通过它来找到对应服务。
特征 是每个服务中的具体数据点或控制机制。例如，它们可能是只读 (获取传感器数据) 、只写 (发送命令) 或两者兼有。有些特征还能在其值发生变化时自动通知手机，这对于实时健康监测尤为重要。
当手机连接到戒指时，会定位所需的服务，并与特定特征交互以发送命令或接收数据。这种结构化的方法不仅确保了通信效率，还能延长电池使用时间。了解了这些基础知识后，让我们开始构建吧！
设置 Xcode 项目
创建一个名为 Halo 的新项目，目标平台为 iOS。组织标识符建议使用反向域名格式 (如 com.example) 。本项目中，我们使用 com.FirstNameLastName。
接下来，为应用启用必要的功能。在 Xcode 中，打开 Signing & Capabilities 选项卡，启用以下 后台模式 (Background Modes)，以确保应用在后台运行时能够保持与戒指的连接并处理数据。
然后，我们将使用 Apple 提供的最新框架
当用户尝试将 COLMI R02 戒指连接到应用时，AccessorySetupKit 会显示一个系统界面，仅列出兼容的附近设备。用户选择设备后，应用即可与戒指通信，而无需请求完整的蓝牙权限。这大大提升了用户隐私，同时简化了设备连接的管理流程。
打开 Info.plist 文件 (可以在左侧边栏中找到，或通过 Project Navigator (⌘1) > Your Target > Info 定位) 。添加以下键值条目以支持与 COLMI R02 戒指的配对：
添加 NSAccessorySetupKitSupports，类型为 Array，并将 Bluetooth 作为第一个项目。
添加 NSAccessorySetupBluetoothServices，类型为 Array，并将以下 UUID 作为 String 项：
6E40FFF0-B5A3-F393-E0A9-E50E24DCCA9E
0000180A-0000-1000-8000-00805F9B34FB
至此，初步配置完成！?
Ring Session Manager 类
接下来，我们将创建一个 RingSessionManager 类，用于管理所有与戒指的通信。此类的主要职责包括：
扫描附近的戒指
连接到戒指
发现服务和特征
实现数据读写操作
第一步：创建 RingSessionManager
首先创建一个新的 Swift 文件 (⌘N) ，命名为 RingSessionManager.swift。以下是类的定义以及需要实现的关键属性：
@Observable
class RingSessionManager: NSObject {
// 追踪连接状态
var peripheralConnected = false
var pickerDismissed = true
// 存储当前连接的戒指
var currentRing: ASAccessory?
private var session = ASAccessorySession()
// 核心蓝牙对象
private var manager: CBCentralManager?
private var peripheral: CBPeripheral?}
第二步：发现戒指
戒指通过特定的蓝牙服务 UUID 进行广播。为了找到它，我们需要创建一个 ASDiscoveryDescriptor 对象，指定其蓝牙服务的 UUID。以下代码完成了这一功能：
private static let ring: ASPickerDisplayItem = {
let descriptor = ASDiscoveryDescriptor()
descriptor.bluetoothServiceUUID = CBUUID(string: "6E40FFF0-B5A3-F393-E0A9-E50E24DCCA9E")
return ASPickerDisplayItem(
name: "COLMI R02 Ring",
productImage: UIImage(named: "colmi")!, descriptor: descriptor )}()
确保将戒指图片添加到项目资源目录中，或者用合适的占位符替换 UIImage(named: "colmi")!。
第三步：显示戒指选择器
为了让用户选择戒指，我们调用系统内置的设备选择器界面：
func presentPicker() {
session.showPicker(for: [Self.ring]) { error in
if let error {
print("Failed to show picker: \(error.localizedDescription)") } }}
第四步：处理戒指选择
当用户从选择器中选定设备后，应用需要处理连接和管理逻辑。以下代码实现了事件处理：
private func handleSessionEvent(event: ASAccessoryEvent) {
switch event.eventType {
case .accessoryAdded:
guard let ring = event.accessory else { return } saveRing(ring: ring)
case .activated:
// 重新连接已配对戒指
guard let ring = session.accessories.first else { return } saveRing(ring: ring)
case .accessoryRemoved:
currentRing = nil
manager = nil }}
第五步：建立连接
完成选择戒指后，我们需要与其建立蓝牙连接：
func connect() {
guard let manager, manager.state == .poweredOn, let peripheral else { return }
let options: [String: Any] = [
CBConnectPeripheralOptionNotifyOnConnectionKey: true,
CBConnectPeripheralOptionNotifyOnDisconnectionKey: true,
CBConnectPeripheralOptionStartDelayKey: 1 ] manager.connect(peripheral, options: options)}
第六步：理解委托方法
在 RingSessionManager 中，我们实现了两个关键的委托协议，用于管理蓝牙通信过程。
中央管理器委托 (CBCentralManagerDelegate)此委托主要处理蓝牙连接的整体状态。
func centralManagerDidUpdateState(_ central: CBCentralManager) {
print("Central manager state: \(central.state)")
switch central.state {
case .poweredOn:
if let peripheralUUID = currentRing?.bluetoothIdentifier {
if let knownPeripheral = central.retrievePeripherals(withIdentifiers: [peripheralUUID]).first {
print("Found previously connected peripheral") peripheral = knownPeripheral
peripheral?.delegate = self connect()
} else {
print("Known peripheral not found, starting scan") } }
default:
peripheral = nil }}
当蓝牙开启时，程序会检查是否有已连接的戒指，并尝试重新连接。
成功连接后：
func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
print("DEBUG: Connected to peripheral: \(peripheral)")
peripheral.delegate = self
print("DEBUG: Discovering services...")
peripheral.discoverServices([CBUUID(string: Self.ringServiceUUID)])
peripheralConnected = true}
断开连接时：
func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: (any Error)?) {
print("Disconnected from peripheral: \(peripheral)")
peripheralConnected = false
characteristicsDiscovered = false}
外设委托 (CBPeripheralDelegate)
此委托主要处理与戒指的具体通信。
首先发现戒指的服务：
func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: (any Error)?) {
print("DEBUG: Services discovery callback, error: \(String(describing: error))")
guard error == nil, let services = peripheral.services else {
print("DEBUG: No services found or error occurred")
return }
print("DEBUG: Found \(services.count) services")
for service in services {
if service.uuid == CBUUID(string: Self.ringServiceUUID) {
print("DEBUG: Found ring service, discovering characteristics...") peripheral.discoverCharacteristics([
CBUUID(string: Self.uartRxCharacteristicUUID),
CBUUID(string: Self.uartTxCharacteristicUUID)
], for: service) } }}
发现特征后：
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
print("DEBUG: Characteristics discovery callback, error: \(String(describing: error))")
guard error == nil, let characteristics = service.characteristics else {
print("DEBUG: No characteristics found or error occurred")
return }
print("DEBUG: Found \(characteristics.count) characteristics")
for characteristic in characteristics {
switch characteristic.uuid {
case CBUUID(string: Self.uartRxCharacteristicUUID):
print("DEBUG: Found UART RX characteristic")
self.uartRxCharacteristic = characteristic
case CBUUID(string: Self.uartTxCharacteristicUUID):
print("DEBUG: Found UART TX characteristic")
self.uartTxCharacteristic = characteristic
peripheral.setNotifyValue(true, for: characteristic)
default:
print("DEBUG: Found other characteristic: \(characteristic.uuid)") } }
characteristicsDiscovered = true}
接收数据时：
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if characteristic.uuid == CBUUID(string: Self.uartTxCharacteristicUUID) {
if let value = characteristic.value {
print("Received value: \(value)") } }}
发送命令后：
func peripheral(_ peripheral: CBPeripheral, didWriteValueFor characteristic: CBCharacteristic, error: Error?) {
if let error = error {
print("Write to characteristic failed: \(error.localizedDescription)")
} else {
print("Write to characteristic successful") }}
完整代码
完整的 RingSessionManager 类代码如下：
import Foundation
import AccessorySetupKit
import CoreBluetooth
import SwiftUI
@Observable
class RingSessionManager: NSObject {
var peripheralConnected = false
var pickerDismissed = true
var currentRing: ASAccessory?
private var session = ASAccessorySession()
private var manager: CBCentralManager?
private var peripheral: CBPeripheral?
private var uartRxCharacteristic: CBCharacteristic?
private var uartTxCharacteristic: CBCharacteristic?
private static let ringServiceUUID = "6E40FFF0-B5A3-F393-E0A9-E50E24DCCA9E"
private static let uartRxCharacteristicUUID = "6E400002-B5A3-F393-E0A9-E50E24DCCA9E"
private static let uartTxCharacteristicUUID = "6E400003-B5A3-F393-E0A9-E50E24DCCA9E"
private static let deviceInfoServiceUUID = "0000180A-0000-1000-8000-00805F9B34FB"
private static let deviceHardwareUUID = "00002A27-0000-1000-8000-00805F9B34FB"
private static let deviceFirmwareUUID = "00002A26-0000-1000-8000-00805F9B34FB"
private static let ring: ASPickerDisplayItem = {
let descriptor = ASDiscoveryDescriptor()
descriptor.bluetoothServiceUUID = CBUUID(string: ringServiceUUID)
return ASPickerDisplayItem(
name: "COLMI R02 Ring",
productImage: UIImage(named: "colmi")!, descriptor: descriptor ) }()
private var characteristicsDiscovered = false
override init() {
super.init()
self.session.activate(on: DispatchQueue.main, eventHandler: handleSessionEvent(event:)) }
// MARK: - RingSessionManager actions
func presentPicker() {
session.showPicker(for: [Self.ring]) { error in
if let error {
print("Failed to show picker due to: \(error.localizedDescription)") } } }
func removeRing() {
guard let currentRing else { return }
if peripheralConnected { disconnect() }
session.removeAccessory(currentRing) { _ in
self.currentRing = nil
self.manager = nil } }
func connect() {
guard
let manager, manager.state == .poweredOn,
let peripheral
else {
return }
let options: [String: Any] = [
CBConnectPeripheralOptionNotifyOnConnectionKey: true,
CBConnectPeripheralOptionNotifyOnDisconnectionKey: true,
CBConnectPeripheralOptionStartDelayKey: 1 ] manager.connect(peripheral, options: options) }
func disconnect() {
guard let peripheral, let manager else { return } manager.cancelPeripheralConnection(peripheral) }
// MARK: - ASAccessorySession functions
private func saveRing(ring: ASAccessory) { currentRing = ring
if manager == nil {
manager = CBCentralManager(delegate: self, queue: nil) } }
private func handleSessionEvent(event: ASAccessoryEvent) {
switch event.eventType {
case .accessoryAdded, .accessoryChanged:
guard let ring = event.accessory else { return } saveRing(ring: ring)
case .activated:
guard let ring = session.accessories.first else { return } saveRing(ring: ring)
case .accessoryRemoved:
self.currentRing = nil
self.manager = nil
case .pickerDidPresent:
pickerDismissed = false
case .pickerDidDismiss:
pickerDismissed = true
default:
print("Received event type \(event.eventType)") } }}
// MARK: - CBCentralManagerDelegate
extension RingSessionManager: CBCentralManagerDelegate {
func centralManagerDidUpdateState(_ central: CBCentralManager) {
print("Central manager state: \(central.state)")
switch central.state {
case .poweredOn:
if let peripheralUUID = currentRing?.bluetoothIdentifier {
if let knownPeripheral = central.retrievePeripherals(withIdentifiers: [peripheralUUID]).first {
print("Found previously connected peripheral") peripheral = knownPeripheral
peripheral?.delegate = self connect()
} else {
print("Known peripheral not found, starting scan") } }
default:
peripheral = nil } }
func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
print("DEBUG: Connected to peripheral: \(peripheral)")
peripheral.delegate = self
print("DEBUG: Discovering services...")
peripheral.discoverServices([CBUUID(string: Self.ringServiceUUID)])
peripheralConnected = true }
func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: (any Error)?) {
print("Disconnected from peripheral: \(peripheral)")
peripheralConnected = false
characteristicsDiscovered = false }
func centralManager(_ central: CBCentralManager, didFailToConnect peripheral: CBPeripheral, error: (any Error)?) {
print("Failed to connect to peripheral: \(peripheral), error: \(error.debugDescription)") }}
// MARK: - CBPeripheralDelegate
extension RingSessionManager: CBPeripheralDelegate {
func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: (any Error)?) {
print("DEBUG: Services discovery callback, error: \(String(describing: error))")
guard error == nil, let services = peripheral.services else {
print("DEBUG: No services found or error occurred")
return }
print("DEBUG: Found \(services.count) services")
for service in services {
if service.uuid == CBUUID(string: Self.ringServiceUUID) {
print("DEBUG: Found ring service, discovering characteristics...") peripheral.discoverCharacteristics([
CBUUID(string: Self.uartRxCharacteristicUUID),
CBUUID(string: Self.uartTxCharacteristicUUID)
], for: service) } } }
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
print("DEBUG: Characteristics discovery callback, error: \(String(describing: error))")
guard error == nil, let characteristics = service.characteristics else {
print("DEBUG: No characteristics found or error occurred")
return }
print("DEBUG: Found \(characteristics.count) characteristics")
for characteristic in characteristics {
switch characteristic.uuid {
case CBUUID(string: Self.uartRxCharacteristicUUID):
print("DEBUG: Found UART RX characteristic")
self.uartRxCharacteristic = characteristic
case CBUUID(string: Self.uartTxCharacteristicUUID):
print("DEBUG: Found UART TX characteristic")
self.uartTxCharacteristic = characteristic
peripheral.setNotifyValue(true, for: characteristic)
default:
print("DEBUG: Found other characteristic: \(characteristic.uuid)") } }
characteristicsDiscovered = true }
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if characteristic.uuid == CBUUID(string: Self.uartTxCharacteristicUUID) {
if let value = characteristic.value {
print("Received value: \(value)") } } }
func peripheral(_ peripheral: CBPeripheral, didWriteValueFor characteristic: CBCharacteristic, error: Error?) {
if let error = error {
print("Write to characteristic failed: \(error.localizedDescription)")
} else {
print("Write to characteristic successful") } }}
最后一步：将其应用到我们的应用程序中
在 ContentView.swift 中粘贴以下代码，作为主界面的一部分：
import SwiftUI
import AccessorySetupKit
struct ContentView: View {
@State var ringSessionManager = RingSessionManager()
var body: some View {
List {
Section("MY DEVICE", content: {
if ringSessionManager.pickerDismissed, let currentRing = ringSessionManager.currentRing { makeRingView(ring: currentRing)
} else {
Button { ringSessionManager.presentPicker() } label: {
Text("Add Ring") .frame(maxWidth: .infinity)
.font(Font.headline.weight(.semibold)) } } }) }.listStyle(.insetGrouped) }
@ViewBuilder
private func makeRingView(ring: ASAccessory) -> some View {
HStack {
Image("colmi") .resizable() .aspectRatio(contentMode: .fit)
.frame(height: 70)
VStack(alignment: .leading) {
Text(ring.displayName)
.font(Font.headline.weight(.semibold)) } } }}
#Preview {
ContentView()}
如果一切配置正确，你现在可以构建并运行应用。当点击“Add Ring”按钮时，将弹出一个界面，显示附近的兼容设备 (包括 COLMI R02 戒指) 。选择设备后，应用即可完成连接。?
在后续的文章中，我们将进一步探索如何与戒指交互，包括读取电池电量、获取传感器数据 (如 PPG 和加速度计) ，并基于这些数据开发实时心率监测、活动追踪及睡眠检测功能。敬请期待！
英文原文:
https://hf.co/blog/cyrilzakka/halo-introduction 原文作者: Cyril, ML Researcher, Health AI Lead @ Hugging Face
译者: Lu Cheng, Hugging Face Fellow
