feat: support BLE low power mode

.idea/gradle.xml

@@ -4,16 +4,15 @@
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>
-        <option name="testRunner" value="GRADLE" />
-        <option name="distributionType" value="DEFAULT_WRAPPED" />
         <option name="externalProjectPath" value="$PROJECT_DIR$" />
-        <option name="gradleJvm" value="jbr-17" />
+        <option name="gradleJvm" value="#GRADLE_LOCAL_JAVA_HOME" />
         <option name="modules">
           <set>
             <option value="$PROJECT_DIR$" />
             <option value="$PROJECT_DIR$/app" />
           </set>
         </option>
+        <option name="resolveExternalAnnotations" value="false" />
       </GradleProjectSettings>
     </option>
   </component>

app/src/main/java/com/logitech/vc/kirbytest/ConnectionManager.kt

@@ -292,10 +292,6 @@ class ConnectionManager(val context: Context, bleAdapter: BluetoothAdapter)  {
     @SuppressLint("MissingPermission")
     val scanCallback = object : ScanCallback() {
         override fun onScanResult(callbackType: Int, result: ScanResult) {
-            Log.d(
-                "ScanCallback",
-                "Found BLE device with address ${result.device.address} (name: ${result.device.name}, rssi: ${result.rssi})"
-            )
             notifyListeners(result.device.address) { it.onScanResult(callbackType, result) }
         }
 

app/src/main/java/com/logitech/vc/kirbytest/DecoderIaq.kt

@@ -55,6 +55,10 @@ object DecoderIaq {
             parseUnsignedInt(inputBytes, 8, 9) ushr 4 and INVALID_OCCUPANCY
         measurement.occupancy = if (occupancy == INVALID_OCCUPANCY) null else occupancy
 
+        val occupancy2 =
+            parseUnsignedInt(inputBytes, 10, 11) ushr 4 and INVALID_OCCUPANCY
+        measurement.occupancy = if (occupancy == INVALID_OCCUPANCY) null else occupancy
+
         if (msgType == 0) {
             val pm25 =
                 parseUnsignedInt(inputBytes, 8, 10) ushr 2 and INVALID_PM25

app/src/main/java/com/logitech/vc/kirbytest/KirbyDevice.kt

@@ -16,8 +16,6 @@ import com.android.volley.toolbox.JsonObjectRequest
 import com.android.volley.toolbox.Volley
 import org.json.JSONException
 import org.json.JSONObject
-import java.nio.ByteBuffer
-import java.nio.ByteOrder
 import java.time.LocalDateTime
 import java.time.format.DateTimeFormatter
 import java.util.Base64
@@ -35,6 +33,7 @@ enum class DeviceStatus {
 
 @SuppressLint("MissingPermission")
 class KirbyDevice(
+
     private val context: Context,
     private val connectionManager: ConnectionManager,
     private val bleDevice: BluetoothDevice,
@@ -45,7 +44,11 @@ class KirbyDevice(
 
 
     ) : BleListener(bleDevice.address), DeviceListEntry {
+    private val tag = "KirbyDevice"
+    private var lastSeen: Long = 0
     private val queue: RequestQueue = Volley.newRequestQueue(context)
+    private val reconnectionDelayMs = 10_000
+    private val settings = settingsRepository.getSettings()
 
     fun subscribe() {
         if(statuses.contains(DeviceStatus.CONNECTED)) {
@@ -56,8 +59,14 @@ class KirbyDevice(
     }
 
     fun connect() {
-        connectionManager.connect(bleDevice)
+        val now = System.currentTimeMillis()
-        connectionManager.discoverServices(bleDevice)
+        if (now - lastSeen > reconnectionDelayMs) {
+            Log.i(tag, "Connecting to device " + bleDevice.address)
+            connectionManager.connect(bleDevice)
+            connectionManager.discoverServices(bleDevice)
+        } else{
+            Log.i(tag, "Waiting before reconnecting to device " + bleDevice.address)
+        }
     }
 
     fun readIaq() {
@@ -69,7 +78,9 @@ class KirbyDevice(
         gatt: BluetoothGatt,
         characteristic: BluetoothGattCharacteristic
     ) {
+
         addMeasurement(characteristic)
+
         onStateChange(this)
     }
 
@@ -96,10 +107,18 @@ class KirbyDevice(
         statuses.remove(DeviceStatus.CONNECTED)
         statuses.remove(DeviceStatus.SUBSCRIBED)
         onStateChange(this)
+        Log.i(tag, "Disconnected")
     }
 
     override fun onCharChange(gatt: BluetoothGatt, characteristic: BluetoothGattCharacteristic) {
         addMeasurement(characteristic)
+        lastSeen = System.currentTimeMillis()
+
+        if(settings.lowPowerMode){
+            Log.i(tag, "Received data, closing connection")
+            connectionManager.teardownConnection(bleDevice)
+        }
+
         onStateChange(this)
     }
 
@@ -145,7 +164,7 @@ class KirbyDevice(
     private fun addMeasurement(characteristic: BluetoothGattCharacteristic) {
         val hexPayload = characteristic.value.toHexString().substring(2)
         val measurement = DecoderIaq.parseMeasurement(hexPayload)
-        var payload : Payload
+        val payload : Payload
         if (measurement == null) {
             payload = Payload(hexPayload)
         } else {
@@ -167,7 +186,6 @@ class KirbyDevice(
     }
 
     private fun publishMeasurement(payload: String) {
-        val settings = settingsRepository.readSettings()
         val accessKey = settings.apiKey
         val url = settings.apiUrl
 
@@ -376,26 +394,11 @@ data class Payload(
         .format(DateTimeFormatter.ofPattern("dd.MM.yy HH:mm:ss"))
 )
 
-fun bytesToUInt16(arr: ByteArray, start: Int): Int {
-    return ByteBuffer.wrap(arr, start, 2)
-        .order(ByteOrder.LITTLE_ENDIAN).short.toInt() and 0xFFFF
-}
-
-fun bytesToInt16(arr: ByteArray, start: Int): Short {
-    return ByteBuffer.wrap(arr, start, 2)
-        .order(ByteOrder.LITTLE_ENDIAN).short
-}
-
-fun bytesToInt32(arr: ByteArray, start: Int): Int {
-    return ByteBuffer.wrap(arr, start, 4)
-        .order(ByteOrder.LITTLE_ENDIAN).int
-}
-
 
 private fun payloadToMeasurements(payload: Payload): List<Measurement> {
     return listOf(object : Measurement {
         override fun getLabel(): String {
-            return payload.ts.toString()
+            return payload.ts
         }
 
         override fun getFormattedValue(): String {

app/src/main/java/com/logitech/vc/kirbytest/MainActivity.kt

@@ -81,7 +81,7 @@ class MainActivity : AppCompatActivity() {
         newConnectionManager()
     }
 
-    private val kirbyDevices = mutableListOf<DeviceListEntry>()
+    private val kirbyDevices = mutableListOf<KirbyDevice>()
 
     private val deviceListAdapter: DeviceListAdapter by lazy {
         DeviceListAdapter(kirbyDevices)
@@ -139,14 +139,14 @@ class MainActivity : AppCompatActivity() {
 
         if (hasRequiredRuntimePermissions()) {
             connectionManager.startScan()
-
+            /*
             lifecycleScope.launch {
-
                 withContext(Dispatchers.Main) {
                     delay(5000L)
                     connectionManager.stopScan()
                 }
             }
+            */
         }
 
         Timer().schedule(object : TimerTask() {
@@ -209,14 +209,6 @@ class MainActivity : AppCompatActivity() {
     }
 
 
-    @SuppressLint("NotifyDataSetChanged")
-    private fun addDummyDevices() {
-        for (i in 0..14) {
-            kirbyDevices.add(DummyListEntry("$i"))
-        }
-        deviceListAdapter.notifyDataSetChanged()
-    }
-
     private fun newConnectionManager(): ConnectionManager {
         val mngr = ConnectionManager(applicationContext, bluetoothAdapter)
         mngr.register(object : BleListener(null) {
@@ -237,19 +229,15 @@ class MainActivity : AppCompatActivity() {
                         "ScanCallback",
                         "Found Kirby device with name ${result.device.name} (address: ${result.device.address}, rssi: ${result.rssi})"
                     )
-                    val kirbyDevice = kirbyDevices.find { it.address == result.device.address }
+                    var kirbyDevice = kirbyDevices.find { it.address == result.device.address }
                     if (kirbyDevice == null) {
-                        val kirby = newKirbyDevice(result.device)
+                        kirbyDevice = newKirbyDevice(result.device)
-                        kirby.onScanResult(callbackType, result)
+                        kirbyDevice.onScanResult(callbackType, result)
                     }
 
                     if (bondedDevices.contains(result.device.address)) {
-                        Log.i("KirbyDevice", "Connecting to " + result.device.address)
+                        Log.i("KirbyDevice", "Auto connecting to bonded device" + result.device.address)
-
+                        kirbyDevice.connect()
-                        connectionManager.connect(result.device)
-
-                        //connectionManager.readRemoteRssi(result.device)
-                        connectionManager.discoverServices(result.device)
                     }
 
                 }

app/src/main/java/com/logitech/vc/kirbytest/Settings.kt

@@ -5,8 +5,10 @@ import android.content.Context
 import android.content.DialogInterface
 import android.util.Log
 import android.view.LayoutInflater
+import android.widget.CheckBox
 import android.widget.EditText
 import androidx.appcompat.app.AlertDialog
+import androidx.datastore.preferences.core.booleanPreferencesKey
 import androidx.datastore.preferences.preferencesDataStore
 import com.logitech.vc.kirbytest.BuildConfig
 import com.logitech.vc.kirbytest.R
@@ -33,30 +35,35 @@ class SettingsRepository(context: Context) {
     companion object {
         val API_URL = stringPreferencesKey("api_url")
         val API_KEY = stringPreferencesKey("api_key")
+        val BLE_LOW_POWER_MODE = booleanPreferencesKey("ble_low_power_mode")
     }
 
     @OptIn(DelicateCoroutinesApi::class)
-    fun saveSettings(apiUrl: String, apiKey: String) {
+    fun saveSettings(apiUrl: String, apiKey: String, isLowPowerMode: Boolean) {
         settings.apiKey = apiKey
         settings.apiUrl = apiUrl
+        settings.lowPowerMode = isLowPowerMode
 
         coroutineScope.launch(Dispatchers.Main) {
             dataStore.edit { preferences ->
                 preferences[API_URL] = apiUrl
                 preferences[API_KEY] = apiKey
+                preferences[BLE_LOW_POWER_MODE] = isLowPowerMode
             }
         }
 
     }
 
-    fun readSettings(): Settings {
+    fun getSettings(): Settings {
         return settings
     }
 
     private val settingsFlow: Flow<Settings> = dataStore.data.map {
         Settings(
             apiUrl = it[API_URL] ?: BuildConfig.API_BASE_URL,
-            apiKey = it[API_KEY] ?: BuildConfig.API_KEY
+            apiKey = it[API_KEY] ?: BuildConfig.API_KEY,
+            lowPowerMode = it[BLE_LOW_POWER_MODE] ?: true
+
         )
     }
 
@@ -65,11 +72,12 @@ class SettingsRepository(context: Context) {
         if (result != null) {
             settings.apiKey = result.apiKey
             settings.apiUrl = result.apiUrl
+            settings.lowPowerMode = result.lowPowerMode
         }
     }
 }
 
-data class Settings(var apiUrl: String, var apiKey: String)
+data class Settings(var apiUrl: String, var apiKey: String, var lowPowerMode: Boolean = true)
 
 
 fun settingsDialog(context: Context, settingsRepo: SettingsRepository): AlertDialog {
@@ -79,10 +87,12 @@ fun settingsDialog(context: Context, settingsRepo: SettingsRepository): AlertDia
     val root = layoutInflater.inflate(R.layout.settings_dialog, null)
     val urlField = root.findViewById<EditText>(R.id.apiUrl)
     val keyField = root.findViewById<EditText>(R.id.apiKey)
+    val lowPowerMode = root.findViewById<CheckBox>(R.id.checkboxLowPowerMode)
 
-    val settings = settingsRepo.readSettings()
+    val settings = settingsRepo.getSettings()
     urlField.setText(settings.apiUrl)
     keyField.setText(settings.apiKey)
+    lowPowerMode.isChecked = settings.lowPowerMode
 
     return androidx.appcompat.app.AlertDialog.Builder(context)
         .setTitle(R.string.settings)
@@ -92,8 +102,9 @@ fun settingsDialog(context: Context, settingsRepo: SettingsRepository): AlertDia
 
             val url = urlField.text.toString()
             val key = keyField.text.toString()
+            val isLowPowerMode = lowPowerMode.isChecked
             if (isFullPath(url) || url.isEmpty()) {
-                settingsRepo.saveSettings(url, key)
+                settingsRepo.saveSettings(url, key, isLowPowerMode)
             }
 
         }

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

@@ -51,6 +51,12 @@
             android:inputType="text"
             android:text="" />
 
+        <CheckBox android:id="@+id/checkboxLowPowerMode"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="BLE low power mode"/>
+
+
 
     </LinearLayout>
 </androidx.constraintlayout.widget.ConstraintLayout>

build.gradle

@@ -1,6 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 plugins {
-    id 'com.android.application' version '8.1.2' apply false
+    id 'com.android.application' version '8.5.0' apply false
-    id 'com.android.library' version '8.1.2' apply false
+    id 'com.android.library' version '8.5.0' apply false
     id 'org.jetbrains.kotlin.android' version '1.8.20' apply false
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 #Wed Jun 14 12:17:09 CEST 2023
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists