basic component

README.md

@@ -1 +1,23 @@
-# wearos-heartmonitor-wss
+# wearos-heartmonitor-wss
+
+Wear OS app that streams heart rate in real time over secure WebSocket.
+
+## Build
+- Android Studio Jellyfish/Koala, SDK 34
+- Open the project, select **app** run config, deploy to Pixel Watch 3 (Wear OS 4)
+
+## Configure
+On the watch:
+1. Open the app
+2. Set **Server URL**: `wss://watch.puls.mrunk.de/ws`
+3. Paste **JWT** token ("Bearer" not needed)
+4. Tap **Save** → **Start**
+
+## Server expectations
+- Accept `Authorization: Bearer <JWT>`
+- Receive JSON like: `{ "type":"hr", "bpm":92, "ts":"2025-08-13T10:15:30Z", "source":"wearos-healthservices" }`
+
+## Notes
+- App starts a Foreground Service to keep streaming alive
+- Uses Health Services Exercise API for stable, low-latency HR
+- No data stored on device; only in-flight streaming

app/build.gradle.kts

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+import com.android.build.api.dsl.ApplicationDefaultConfig
+
+plugins {
+    id("com.android.application")
+    kotlin("android")
+}
+
+android {
+    namespace = "com.mrunk.wearhr"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "com.mrunk.wearhr"
+        minSdk = 30 // Wear OS 3+
+        targetSdk = 34
+        versionCode = 1
+        versionName = "0.1.0"
+
+        // Allow cleartext OFF by default; we use WSS.
+        resourceConfigurations += listOf("en", "de")
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = true
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+        debug {
+            isMinifyEnabled = false
+        }
+    }
+
+    packaging.resources.excludes += "META-INF/{AL2.0,LGPL2.1}"
+
+    buildFeatures { viewBinding = true }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+    kotlinOptions { jvmTarget = "17" }
+
+    // Network security: enforce TLS (can be relaxed for local testing)
+    defaultConfig {
+        manifestPlaceholders["networkSecurityConfig"] = "@xml/network_security_config"
+    }
+}
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.13.1")
+    implementation("androidx.appcompat:appcompat:1.7.0")
+    implementation("androidx.activity:activity-ktx:1.9.2")
+    implementation("androidx.constraintlayout:constraintlayout:2.1.4")
+
+    // Wear OS UI helpers (optional, for round screens)
+    implementation("androidx.wear:wear:1.3.0")
+
+    // Health Services client (Wear OS)
+    implementation("androidx.health:health-services-client:1.1.0")
+
+    // OkHttp WebSocket
+    implementation("com.squareup.okhttp3:okhttp:4.12.0")
+
+    // JSON
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.3")
+}

app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-feature android:name="android.hardware.type.watch"/>
+    <uses-feature android:name="android.hardware.sensor.heartrate" android:required="false"/>
+
+    <uses-permission android:name="android.permission.BODY_SENSORS"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_HEALTH"/>
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
+    <uses-permission android:name="android.permission.WAKE_LOCK"/>
+    <uses-permission android:name="android.permission.INTERNET"/>
+
+    <application
+        android:label="Wear HR"
+        android:usesCleartextTraffic="false"
+        android:allowBackup="false"
+        android:networkSecurityConfig="@xml/network_security_config">
+
+        <service
+            android:name=".HrStreamService"
+            android:exported="false"
+            android:foregroundServiceType="healthData">
+        </service>
+
+        <activity android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+        </activity>
+
+    </application>
+</manifest>

app/src/main/java/com/mrunk/wearhr/Health.kt

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+package com.mrunk.wearhr
+
+import android.content.Context
+import android.util.Log
+import androidx.health.services.client.ExerciseClient
+import androidx.health.services.client.HealthServices
+import androidx.health.services.client.data.DataType
+import androidx.health.services.client.data.ExerciseCapabilities
+import androidx.health.services.client.data.ExerciseConfig
+import androidx.health.services.client.data.ExerciseGoal
+import androidx.health.services.client.data.ExerciseType
+import androidx.health.services.client.data.HeartRateAccuracy
+import androidx.health.services.client.data.IntervalGoal
+import androidx.health.services.client.data.SetGoal
+import androidx.health.services.client.event.ExerciseUpdate
+import androidx.health.services.client.event.ExerciseUpdateListener
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+
+class Health(private val ctx: Context, private val onHr: (Int) -> Unit) : ExerciseUpdateListener {
+    private val scope = CoroutineScope(Dispatchers.Default + Job())
+    private val exerciseClient: ExerciseClient = HealthServices.getClient(ctx).exerciseClient
+
+    suspend fun start() {
+        val caps: ExerciseCapabilities = exerciseClient.getCapabilitiesAsync().await()
+        if (!caps.supportedExerciseTypes.contains(ExerciseType.OTHER_WORKOUT)) {
+            Log.w("Health", "Exercise OTHER_WORKOUT not supported; trying without exercise")
+        }
+        val config = ExerciseConfig(
+            exerciseType = ExerciseType.OTHER_WORKOUT,
+            dataTypes = setOf(DataType.HEART_RATE_BPM)
+        )
+        exerciseClient.setUpdateListener(this)
+        exerciseClient.startExerciseAsync(config).await()
+    }
+
+    suspend fun stop() {
+        exerciseClient.pauseExerciseAsync().await()
+        exerciseClient.endExerciseAsync().await()
+        exerciseClient.clearUpdateListener()
+    }
+
+    override fun onExerciseUpdateReceived(update: ExerciseUpdate) {
+        val hr = update.latestMetrics[DataType.HEART_RATE_BPM]
+        val bpm = hr?.value?.toInt()
+        if (bpm != null && bpm > 0) onHr(bpm)
+    }
+}

app/src/main/java/com/mrunk/wearhr/HrStreamService.kt

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+package com.mrunk.wearhr
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+
+class HrStreamService : Service() {
+    private val scope = CoroutineScope(Dispatchers.Default + Job())
+    private var ws: WsClient? = null
+    private var health: Health? = null
+
+    override fun onCreate() {
+        super.onCreate()
+        createNotifChannel()
+        startForeground(1, notif("Connecting…"))
+        val url = Prefs.getUrl(this)
+        val jwt = Prefs.getJwt(this)
+        ws = WsClient(
+            url, jwt,
+            onOpen = {
+                updateNotif("Streaming HR…")
+                scope.launch {
+                    health = Health(this@HrStreamService) { bpm -> ws?.sendHr(bpm) }
+                    try { health?.start() } catch (_: Throwable) { updateNotif("HR start failed") }
+                }
+            },
+            onClose = { _, _ -> updateNotif("Disconnected") },
+            onError = { updateNotif("WS error: ${'$'}{it.message}") }
+        )
+        ws?.connect()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        scope.launch { runCatching { health?.stop() } }
+        ws?.close()
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    private fun createNotifChannel() {
+        if (Build.VERSION.SDK_INT >= 26) {
+            val nm = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            nm.createNotificationChannel(NotificationChannel("hr", "HR Streaming", NotificationManager.IMPORTANCE_LOW))
+        }
+    }
+
+    private fun notif(text: String): Notification = NotificationCompat.Builder(this, "hr")
+        .setSmallIcon(R.drawable.ic_heart)
+        .setContentTitle("Wear HR")
+        .setContentText(text)
+        .setOngoing(true)
+        .build()
+
+    private fun updateNotif(text: String) {
+        val nm = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+        nm.notify(1, notif(text))
+    }
+}

app/src/main/java/com/mrunk/wearhr/MainActivity.kt

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+package com.mrunk.wearhr
+
+import android.Manifest
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.os.Bundle
+import android.widget.Button
+import android.widget.EditText
+import android.widget.TextView
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.ContextCompat
+import com.mrunk.wearhr.databinding.ActivityMainBinding
+
+class MainActivity : AppCompatActivity() {
+    private lateinit var binding: ActivityMainBinding
+
+    private val requestPerm = registerForActivityResult(
+        ActivityResultContracts.RequestPermission()
+    ) { granted ->
+        if (!granted) {
+            findViewById<TextView>(R.id.statusText).text = "Permission denied"
+        }
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        binding = ActivityMainBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+
+        binding.inputUrl.setText(Prefs.getUrl(this))
+        binding.inputToken.setText(Prefs.getJwt(this))
+
+        binding.btnSave.setOnClickListener {
+            Prefs.set(this, binding.inputUrl.text.toString(), binding.inputToken.text.toString())
+            binding.statusText.text = "Saved"
+        }
+
+        binding.btnStart.setOnClickListener {
+            ensurePermissionsAndStart()
+        }
+
+        binding.btnStop.setOnClickListener {
+            stopService(Intent(this, HrStreamService::class.java))
+            binding.statusText.text = getString(R.string.status_disconnected)
+        }
+    }
+
+    private fun ensurePermissionsAndStart() {
+        if (ContextCompat.checkSelfPermission(this, Manifest.permission.BODY_SENSORS) != PackageManager.PERMISSION_GRANTED) {
+            requestPerm.launch(Manifest.permission.BODY_SENSORS)
+            return
+        }
+        startForegroundService(Intent(this, HrStreamService::class.java))
+        findViewById<TextView>(R.id.statusText).text = "Starting…"
+    }
+}

app/src/main/java/com/mrunk/wearhr/Prefs.kt

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+package com.mrunk.wearhr
+
+import android.content.Context
+import android.content.SharedPreferences
+
+object Prefs {
+    private const val FILE = "wearhr"
+    private const val KEY_URL = "url"
+    private const val KEY_JWT = "jwt"
+
+    fun prefs(ctx: Context): SharedPreferences = ctx.getSharedPreferences(FILE, Context.MODE_PRIVATE)
+    fun getUrl(ctx: Context) = prefs(ctx).getString(KEY_URL, "") ?: ""
+    fun getJwt(ctx: Context) = prefs(ctx).getString(KEY_JWT, "") ?: ""
+    fun set(ctx: Context, url: String, jwt: String) {
+        prefs(ctx).edit().putString(KEY_URL, url.trim()).putString(KEY_JWT, jwt.trim()).apply()
+    }
+}

app/src/main/java/com/mrunk/wearhr/WsClient.kt

@@ -0,0 +1,55 @@
+package com.mrunk.wearhr
+
+import android.util.Log
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import okhttp3.*
+import okio.ByteString
+import java.util.concurrent.TimeUnit
+
+class WsClient(
+    private val url: String,
+    private val jwt: String,
+    private val onOpen: () -> Unit,
+    private val onClose: (Int, String) -> Unit,
+    private val onError: (Throwable) -> Unit
+) {
+    private val json = Json { ignoreUnknownKeys = true }
+    private val client = OkHttpClient.Builder()
+        .pingInterval(15, TimeUnit.SECONDS)
+        .readTimeout(0, TimeUnit.MILLISECONDS)
+        .build()
+
+    private var ws: WebSocket? = null
+
+    fun connect() {
+        val req = Request.Builder()
+            .url(url)
+            .addHeader("Authorization", "Bearer $jwt")
+            .build()
+        ws = client.newWebSocket(req, object : WebSocketListener() {
+            override fun onOpen(webSocket: WebSocket, response: Response) { onOpen() }
+            override fun onMessage(webSocket: WebSocket, text: String) { /* ignore */ }
+            override fun onMessage(webSocket: WebSocket, bytes: ByteString) { /* ignore */ }
+            override fun onClosed(webSocket: WebSocket, code: Int, reason: String) { onClose(code, reason) }
+            override fun onFailure(webSocket: WebSocket, t: Throwable, response: Response?) { onError(t) }
+        })
+    }
+
+    fun sendHr(bpm: Int) {
+        val payload = json.encodeToString(HrEvent(bpm = bpm))
+        ws?.send(payload)
+    }
+
+    fun close() { ws?.close(1000, "bye") }
+}
+
+@Serializable
+data class HrEvent(
+    val type: String = "hr",
+    val bpm: Int,
+    val ts: String = java.time.Instant.now().toString(),
+    val source: String = "wearos-healthservices",
+    val sessionId: String? = null
+)

app/src/main/res/drawable/ic_heart.xml

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+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp" android:height="24dp" android:viewportWidth="24" android:viewportHeight="24">
+    <path android:fillColor="#FFFFFF" android:pathData="M12,21.35l-1.45,-1.32C5.4,15.36 2,12.28 2,8.5 2,6 4,4 6.5,4c1.74,0 3.41,0.81 4.5,2.09C12.09,4.81 13.76,4 15.5,4 18,4 20,6 20,8.5c0,3.78 -3.4,6.86 -8.55,11.54L12,21.35z"/>
+</vector>

app/src/main/res/layout/activity_main.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:padding="12dp">
+
+    <EditText
+        android:id="@+id/inputUrl"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:hint="@string/server_url"
+        android:inputType="textUri"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"/>
+
+    <EditText
+        android:id="@+id/inputToken"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:hint="@string/jwt_token"
+        android:inputType="textPassword"
+        app:layout_constraintTop_toBottomOf="@id/inputUrl"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"/>
+
+    <TextView
+        android:id="@+id/statusText"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/status_disconnected"
+        app:layout_constraintTop_toBottomOf="@id/inputToken"
+        app:layout_constraintStart_toStartOf="parent"/>
+
+    <Button
+        android:id="@+id/btnSave"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/save"
+        app:layout_constraintTop_toBottomOf="@id/inputToken"
+        app:layout_constraintEnd_toEndOf="parent"/>
+
+    <Button
+        android:id="@+id/btnStart"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:text="@string/start"
+        app:layout_constraintTop_toBottomOf="@id/statusText"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toStartOf="@id/btnStop"
+        app:layout_constraintHorizontalWeight="1"/>
+
+    <Button
+        android:id="@+id/btnStop"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:text="@string/stop"
+        app:layout_constraintTop_toBottomOf="@id/statusText"
+        app:layout_constraintStart_toEndOf="@id/btnStart"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontalWeight="1"/>
+
+</androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -0,0 +1,10 @@
+<resources>
+    <string name="app_name">Wear HR</string>
+    <string name="perm_rationale">Die App benötigt Zugriff auf den Herzfrequenzsensor.</string>
+    <string name="start">Start</string>
+    <string name="stop">Stop</string>
+    <string name="save">Save</string>
+    <string name="server_url">Server URL (wss://...)</string>
+    <string name="jwt_token">JWT Token</string>
+    <string name="status_disconnected">Disconnected</string>
+</resources>

app/src/main/res/xml/network_security_config.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config>
+    <base-config cleartextTrafficPermitted="false" />
+</network-security-config>

build.gradle.kts

@@ -0,0 +1,4 @@
+plugins {
+    id("com.android.application") version "8.5.0" apply false
+    kotlin("android") version "1.9.24" apply false
+}

gradle.properties

@@ -0,0 +1,3 @@
+org.gradle.jvmargs=-Xmx2g -Dfile.encoding=UTF-8
+android.useAndroidX=true
+kotlin.code.style=official

settings.gradle.kts

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+rootProject.name = "wearos-heartmonitor-wss"
+include(":app")