feat: support BLE low power mode

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)
-        connectionManager.discoverServices(bleDevice)
+        val now = System.currentTimeMillis()
+        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 {