feat: display list of measurements

app/build.gradle

@@ -46,5 +46,5 @@ dependencies {
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
-    implementation 'androidx.recyclerview:recyclerview:1.1.0'
+    implementation 'androidx.recyclerview:recyclerview:1.2.0'
 }

app/src/main/java/com/example/sensortestingapp/ConnectionManager.kt

@@ -1,27 +1,16 @@
-/*
- * Copyright 2019 Punch Through Design LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 package com.example.sensortestingapp
 
 import android.annotation.SuppressLint
+import android.bluetooth.BluetoothAdapter
 import android.bluetooth.BluetoothDevice
 import android.bluetooth.BluetoothGatt
 import android.bluetooth.BluetoothGattCallback
 import android.bluetooth.BluetoothGattCharacteristic
 import android.bluetooth.BluetoothGattDescriptor
 import android.bluetooth.BluetoothProfile
+import android.bluetooth.le.ScanCallback
+import android.bluetooth.le.ScanResult
+import android.bluetooth.le.ScanSettings
 import android.content.Context
 import android.util.Log
 import java.util.UUID
@@ -74,7 +63,19 @@ data class DiscoverServicesRequest(
 ) : BleOperationType()
 
 
-open class BleListener {
+open class BleListener(private val deviceAddress: String?) {
+
+    open fun isRelevantMessage(address: String?): Boolean {
+        if (deviceAddress != null && deviceAddress == address) {
+            return true;
+        }
+        return deviceAddress == null
+    }
+
+    open fun onConnect(gatt: BluetoothGatt) {}
+
+    open fun onDisconnect(gatt: BluetoothGatt) {}
+
     open fun onSuccessfulCharRead(
         gatt: BluetoothGatt,
         characteristic: BluetoothGattCharacteristic
@@ -86,6 +87,27 @@ open class BleListener {
         characteristic: BluetoothGattCharacteristic
     ) {
     }
+
+    open fun onSubscribe(
+        gatt: BluetoothGatt,
+        descriptor: BluetoothGattDescriptor,
+    ) {
+    }
+
+    open fun onUnsubscribe(
+        gatt: BluetoothGatt,
+        descriptor: BluetoothGattDescriptor,
+    ) {
+    }
+
+    open fun onScanningStateChange(isScanning: Boolean) {
+
+    }
+
+    open fun onScanResult(callbackType: Int, result: ScanResult) {
+
+    }
+
 }
 
 
@@ -138,28 +160,67 @@ fun ByteArray.toHexString(): String =
     joinToString(separator = "", prefix = "0x") { String.format("%02X", it) }
 
 @SuppressLint("MissingPermission")
-object ConnectionManager {
+class ConnectionManager(val context: Context, bleAdapter: BluetoothAdapter) {
 
     private val deviceGattMap = ConcurrentHashMap<BluetoothDevice, BluetoothGatt>()
     private val operationQueue = ConcurrentLinkedQueue<BleOperationType>()
     private var pendingOperation: BleOperationType? = null
     private var listeners = ArrayList<BleListener>()
 
+    private val scanSettings = ScanSettings.Builder()
+        .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
+        .build()
+
+    private val bleScanner by lazy {
+        bleAdapter.bluetoothLeScanner
+    }
+
+    var isScanning = false
+        set(value) {
+            field = value
+            notifyListeners(null) {
+                it.onScanningStateChange(value)
+            }
+        }
+
+    @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) }
+        }
+
+        override fun onScanFailed(errorCode: Int) {
+            Log.e("ScanCallback", "onScanFailed: code $errorCode")
+        }
+    }
 
     fun register(listener: BleListener) {
         listeners.add(listener)
     }
 
-    private fun notifyListeners(notifier: (listener: BleListener) -> Unit) {
+
-        listeners.forEach(notifier)
+    fun startScan() {
+        if (!isScanning) {
+            isScanning = true
+            bleScanner.startScan(null, scanSettings, scanCallback)
+        }
+    }
+
+    fun stopScan() {
+        bleScanner.stopScan(scanCallback)
+        isScanning = false
     }
 
 
-    fun connect(device: BluetoothDevice, context: Context) {
+    fun connect(device: BluetoothDevice) {
         if (device.isConnected()) {
             Log.e("ConnectionManager", "Already connected to ${device.address}!")
         } else {
-            enqueueOperation(Connect(device, context.applicationContext))
+            enqueueOperation(Connect(device, context))
         }
     }
 
@@ -174,15 +235,13 @@ object ConnectionManager {
         }
     }
 
-
+    fun requestMtu(device: BluetoothDevice, mtu: Int = Int.MAX_VALUE) {
-    fun requestMtu(device: BluetoothDevice, mtu: Int) {
         enqueueOperation(MtuRequest(device, mtu.coerceIn(GATT_MIN_MTU_SIZE, GATT_MAX_MTU_SIZE)))
 
     }
 
     fun discoverServices(device: BluetoothDevice) {
         enqueueOperation(DiscoverServicesRequest(device))
-
     }
 
     fun readChar(device: BluetoothDevice, service: UUID, char: UUID) {
@@ -200,8 +259,16 @@ object ConnectionManager {
 
     // - Beginning of PRIVATE functions
 
+    private fun notifyListeners(address: String?, notifier: (listener: BleListener) -> Unit) {
+        listeners.filter { n -> n.isRelevantMessage(address) }.forEach(notifier)
+    }
+
+
     @Synchronized
     private fun enqueueOperation(operation: BleOperationType) {
+        if (isScanning) {
+            stopScan()
+        }
         operationQueue.add(operation)
         if (pendingOperation == null) {
             doNextOperation()
@@ -217,11 +284,6 @@ object ConnectionManager {
         }
     }
 
-    /**
-     * Perform a given [BleOperationType]. All permission checks are performed before an operation
-     * can be enqueued by [enqueueOperation].
-     */
-
     @Synchronized
     private fun doNextOperation() {
         if (pendingOperation != null) {
@@ -266,6 +328,9 @@ object ConnectionManager {
                 Log.w("ConnectionManager", "Disconnecting from ${device.address}")
                 gatt.close()
                 deviceGattMap.remove(device)
+                notifyListeners(gatt.device.address) {
+                    it.onDisconnect(gatt)
+                }
                 signalEndOfOperation()
             }
 
@@ -355,11 +420,14 @@ object ConnectionManager {
 
             if (status == BluetoothGatt.GATT_SUCCESS) {
                 if (newState == BluetoothProfile.STATE_CONNECTED) {
-                    Log.w(
+                    Log.i(
                         "ConnectionManager",
                         "onConnectionStateChange: connected to $deviceAddress"
                     )
                     deviceGattMap[gatt.device] = gatt
+                    notifyListeners(gatt.device.address) {
+                        it.onConnect(gatt)
+                    }
                     if (pendingOperation is Connect) {
                         signalEndOfOperation()
                     }
@@ -368,6 +436,9 @@ object ConnectionManager {
                         "ConnectionManager",
                         "onConnectionStateChange: disconnected from $deviceAddress"
                     )
+                    notifyListeners(gatt.device.address) {
+                        it.onDisconnect(gatt)
+                    }
                     teardownConnection(gatt.device)
                 }
             } else {
@@ -388,6 +459,9 @@ object ConnectionManager {
                         "Discovered ${services.size} services for ${device.address}."
                     )
                     printGattTable()
+                    notifyListeners(gatt.device.address) {
+                        it.onConnect(gatt)
+                    }
                 } else {
                     Log.e("ConnectionManager", "Service discovery failed due to status $status")
                     teardownConnection(gatt.device)
@@ -422,7 +496,7 @@ object ConnectionManager {
                             "ConnectionManager",
                             "Read characteristic $uuid (service: ${service.uuid}): ${value.toHexString()}"
                         )
-                        notifyListeners { listener ->
+                        notifyListeners(gatt.device.address) { listener ->
                             listener.onSuccessfulCharRead(
                                 gatt,
                                 characteristic
@@ -462,6 +536,16 @@ object ConnectionManager {
                 descriptor.uuid == CCC_DESCRIPTOR_UUID
                 && op.charId == descriptor.characteristic.uuid && op.serviceId == descriptor.characteristic.service.uuid
             ) {
+
+                if (!descriptor.value.contentEquals(BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE)) {
+                    notifyListeners(gatt.device.address) {
+                        it.onSubscribe(gatt, descriptor)
+                    }
+                } else {
+                    notifyListeners(gatt.device.address) {
+                        it.onUnsubscribe(gatt, descriptor)
+                    }
+                }
                 signalEndOfOperation()
             }
         }
@@ -470,7 +554,12 @@ object ConnectionManager {
             gatt: BluetoothGatt,
             characteristic: BluetoothGattCharacteristic
         ) {
-            notifyListeners { listener -> listener.onCharChange(gatt, characteristic) }
+            notifyListeners(gatt.device.address) { listener ->
+                listener.onCharChange(
+                    gatt,
+                    characteristic
+                )
+            }
         }
 
 

app/src/main/java/com/example/sensortestingapp/DeviceListAdapter.kt

@@ -0,0 +1,147 @@
+package com.example.sensortestingapp
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ArrayAdapter
+import android.widget.Button
+import android.widget.ListView
+import android.widget.PopupMenu
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+
+interface Action {
+    fun getLabel(): String
+    fun getIcon(): String
+    fun execute(): Unit
+}
+
+interface Measurement {
+    fun getLabel(): String
+    fun getFormattedValue(): String
+}
+
+interface DeviceListEntry {
+    val address: String
+
+    var rssi: Int
+
+    val name: String?
+
+    val status: String?
+
+    fun getActions(): List<Action>
+
+    fun getMeasurements(): List<Measurement>
+
+}
+
+@SuppressLint("MissingPermission")
+class DeviceListAdapter(
+    private val items: List<DeviceListEntry>,
+) : RecyclerView.Adapter<DeviceListAdapter.ViewHolder>() {
+
+    /**
+     * Provide a reference to the type of views that you are using
+     * (custom ViewHolder)
+     */
+    class ViewHolder(
+        private val view: View,
+        private val context: Context
+    ) : RecyclerView.ViewHolder(view) {
+
+        val deviceNameView: TextView
+        val macAddressView: TextView
+        val signalStrengthView: TextView
+        val statusView: TextView
+        val measurementsListView: ListView
+        val deviceActions: Button
+
+
+        init {
+            deviceNameView = view.findViewById(R.id.device_name)
+            macAddressView = view.findViewById(R.id.mac_address)
+            signalStrengthView = view.findViewById(R.id.signal_strength)
+            statusView = view.findViewById(R.id.device_status)
+            measurementsListView = view.findViewById(R.id.measurement_fields)
+            deviceActions = view.findViewById(R.id.device_actions)
+        }
+
+        fun bind(result: DeviceListEntry) {
+            deviceNameView.text = result.name ?: "<N/A>"
+            macAddressView.text = result.address
+            signalStrengthView.text = "${result.rssi ?: "-"} dBm"
+            statusView.text = result.status
+            deviceActions.setOnClickListener {
+                val popup = PopupMenu(context, deviceActions)
+                result.getActions().forEach { action ->
+                    popup.menu.add(action.getLabel())
+                        .setOnMenuItemClickListener { menuItem ->
+                            action.execute()
+                            true
+                        }
+                }
+                val inflater = popup.menuInflater
+                inflater.inflate(R.menu.device_menu, popup.menu)
+                popup.show()
+            }
+
+            val measurements = result.getMeasurements()
+
+            val measurementsRowHeight = 100
+            val measurementsAdapter = object :
+                ArrayAdapter<Measurement>(
+                    context,
+                    R.layout.row_measurements_list,
+                    measurements
+                ) {
+                override fun getView(
+                    position: Int,
+                    convertView: View?,
+                    parent: ViewGroup
+                ): View {
+
+                    val measurementView = convertView ?: LayoutInflater.from(parent.context)
+                        .inflate(R.layout.row_measurements_list, parent, false)
+                    measurementView.findViewById<TextView>(R.id.measurement_label).text =
+                        measurements[position].getLabel()
+                    measurementView.findViewById<TextView>(R.id.measurement_value).text =
+                        measurements[position].getFormattedValue()
+                    measurementView.layoutParams.height = measurementsRowHeight
+                    return measurementView
+                }
+
+                override fun isEnabled(position: Int): Boolean {
+                    // make measurement rows unclickable
+                    return false
+                }
+            }
+
+            measurementsListView.adapter = measurementsAdapter
+            measurementsListView.divider = null
+
+            measurementsListView.layoutParams.height = measurementsRowHeight * measurements.size
+        }
+    }
+
+    override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
+        // Create a new view, which defines the UI of the list item
+        val view = LayoutInflater.from(viewGroup.context)
+            .inflate(R.layout.row_device_list, viewGroup, false)
+
+        return ViewHolder(view, viewGroup.context)
+    }
+
+    override fun getItemCount() = items.size
+
+    // Replace the contents of a view (invoked by the layout manager)
+    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+
+        // Get element from your dataset at this position and replace the
+        // contents of the view with that element
+        val item = items[position]
+        holder.bind(item)
+    }
+}

app/src/main/java/com/example/sensortestingapp/KirbyDevice.kt

@@ -0,0 +1,262 @@
+package com.example.sensortestingapp
+
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCharacteristic
+import android.bluetooth.BluetoothGattDescriptor
+import android.bluetooth.le.ScanResult
+import android.util.Log
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+import java.util.EnumSet
+import java.util.UUID
+import java.util.stream.Collectors
+
+private val DEMO_SERVICE_UUID = UUID.fromString("00000000-0001-11E1-9AB4-0002A5D5C51B")
+private val DEMO_CHAR_UUID = UUID.fromString("00140000-0001-11E1-AC36-0002A5D5C51B")
+
+data class DemoPayload(
+    val ts: Int,
+    val pressure: Float,
+    val temperature: Float,
+    val sysTs: String = LocalDateTime.now()
+        .format(DateTimeFormatter.ofPattern("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
+}
+
+
+fun decodeDemoPayload(bytes: ByteArray): DemoPayload {
+    val ts = bytesToUInt16(bytes, 0)
+    val pressure = bytesToInt32(bytes, 2) / 100.0f
+    val temp = bytesToInt16(bytes, 6) / 10.0f;
+    return DemoPayload(ts, pressure, temp)
+}
+
+enum class DeviceStatus {
+    DISCOVERED, CONNECTED, BONDED, SUBSCRIBED
+}
+
+@SuppressLint("MissingPermission")
+class KirbyDevice(
+    private val connectionManager: ConnectionManager,
+    private val bleDevice: BluetoothDevice,
+    initialRssi: Int,
+    private val onStateChange: (device: KirbyDevice) -> Unit
+) : BleListener(bleDevice.address), DeviceListEntry {
+
+    override fun onScanResult(callbackType: Int, result: ScanResult) {
+        statuses.add(DeviceStatus.DISCOVERED)
+        onStateChange(this)
+    }
+
+    override fun onConnect(gatt: BluetoothGatt) {
+        statuses.add(DeviceStatus.CONNECTED)
+        onStateChange(this)
+    }
+
+    override fun onDisconnect(gatt: BluetoothGatt) {
+        statuses.remove(DeviceStatus.CONNECTED)
+        statuses.remove(DeviceStatus.SUBSCRIBED)
+        onStateChange(this)
+    }
+
+    override fun onSuccessfulCharRead(
+        gatt: BluetoothGatt,
+        characteristic: BluetoothGattCharacteristic
+    ) {
+        addMeasurement(characteristic)
+        onStateChange(this)
+    }
+
+    override fun onCharChange(gatt: BluetoothGatt, characteristic: BluetoothGattCharacteristic) {
+        addMeasurement(characteristic)
+        //statuses.add(DeviceStatus.SUBSCRIBED)
+        onStateChange(this)
+    }
+
+    override fun onSubscribe(
+        gatt: BluetoothGatt,
+        descriptor: BluetoothGattDescriptor,
+    ) {
+        statuses.add(DeviceStatus.SUBSCRIBED)
+        onStateChange(this)
+    }
+
+    override fun onUnsubscribe(gatt: BluetoothGatt, descriptor: BluetoothGattDescriptor) {
+        statuses.remove(DeviceStatus.SUBSCRIBED)
+        onStateChange(this)
+    }
+
+    override var rssi = initialRssi
+        set(value) {
+            field = value
+            onStateChange(this)
+        }
+
+    private fun addMeasurement(characteristic: BluetoothGattCharacteristic) {
+        if (characteristic.service.uuid == DEMO_SERVICE_UUID && characteristic.uuid == DEMO_CHAR_UUID) {
+            val payload = decodeDemoPayload(characteristic.value)
+            Log.i("BleListener", "Demo char received: $payload")
+            measurements.add(payload)
+        }
+    }
+
+    private val measurements = ArrayList<DemoPayload>()
+
+    private val statuses = EnumSet.noneOf(DeviceStatus::class.java)
+
+    override val address: String
+        get() = bleDevice.address
+
+
+    override val name: String?
+        get() = bleDevice.name
+
+    override val status: String?
+        get() = statuses.stream().map { it.name }.collect(Collectors.joining(", "))
+
+    //    override fun getRssi(): Int? {
+//        return rssi
+//    }
+
+    override fun getMeasurements(): List<Measurement> {
+        if (measurements.isEmpty()) {
+            return emptyList()
+        }
+        val latest = measurements.last()
+        return listOf(object : Measurement {
+            override fun getLabel(): String {
+                return "TS"
+            }
+
+            override fun getFormattedValue(): String {
+                return "${latest.sysTs} (${latest.ts})"
+            }
+        }, object : Measurement {
+            override fun getLabel(): String {
+                return "Temperature"
+            }
+
+            override fun getFormattedValue(): String {
+                return "${latest.temperature} °C"
+            }
+        }, object : Measurement {
+            override fun getLabel(): String {
+                return "Pressure"
+            }
+
+            override fun getFormattedValue(): String {
+                return "${latest.pressure} hPa"
+            }
+        })
+    }
+
+    override fun getActions(): List<Action> {
+        val actions = mutableListOf<Action>()
+        if (statuses.contains(DeviceStatus.DISCOVERED) && !statuses.contains(DeviceStatus.CONNECTED)
+        ) {
+            actions.add(object : Action {
+                override fun getLabel(): String {
+                    return "Connect"
+                }
+
+                override fun getIcon(): String {
+                    return ""
+                }
+
+                override fun execute() {
+                    connectionManager.connect(bleDevice)
+                    connectionManager.discoverServices(bleDevice)
+                }
+            })
+        }
+
+        if (statuses.contains(DeviceStatus.CONNECTED)) {
+
+            actions.add(object : Action {
+                override fun getLabel(): String {
+                    return "Disconnect"
+                }
+
+                override fun getIcon(): String {
+                    return ""
+                }
+
+                override fun execute() {
+                    connectionManager.teardownConnection(bleDevice)
+                }
+            })
+
+            actions.add(object : Action {
+                override fun getLabel(): String {
+                    return "Fetch Measurement"
+                }
+
+                override fun getIcon(): String {
+                    TODO("Not yet implemented")
+                }
+
+                override fun execute() {
+                    connectionManager.readChar(bleDevice, DEMO_SERVICE_UUID, DEMO_CHAR_UUID)
+                }
+            })
+
+            if (!statuses.contains(DeviceStatus.SUBSCRIBED)) {
+                actions.add(object : Action {
+                    override fun getLabel(): String {
+                        return "Subscribe"
+                    }
+
+                    override fun getIcon(): String {
+                        return ""
+                    }
+
+                    override fun execute() {
+                        connectionManager.enableNotification(
+                            bleDevice, DEMO_SERVICE_UUID, DEMO_CHAR_UUID
+                        )
+                    }
+                })
+            }
+        }
+
+        if (statuses.contains(DeviceStatus.SUBSCRIBED)) {
+            actions.add(object : Action {
+                override fun getLabel(): String {
+                    return "Unsubscribe"
+                }
+
+                override fun getIcon(): String {
+                    return ""
+                }
+
+                override fun execute() {
+                    connectionManager.disableNotification(
+                        bleDevice, DEMO_SERVICE_UUID, DEMO_CHAR_UUID
+                    )
+                }
+            })
+        }
+
+
+        return actions;
+    }
+}

app/src/main/java/com/example/sensortestingapp/MainActivity.kt

@@ -5,12 +5,8 @@ import android.annotation.SuppressLint
 import android.app.Activity
 import android.app.AlertDialog
 import android.bluetooth.BluetoothAdapter
-import android.bluetooth.BluetoothGatt
-import android.bluetooth.BluetoothGattCharacteristic
 import android.bluetooth.BluetoothManager
-import android.bluetooth.le.ScanCallback
 import android.bluetooth.le.ScanResult
-import android.bluetooth.le.ScanSettings
 import android.content.Context
 import android.content.DialogInterface
 import android.content.Intent
@@ -28,26 +24,10 @@ import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.SimpleItemAnimator
 import com.example.sensortestingapp.databinding.ActivityMainBinding
-import java.nio.ByteBuffer
-import java.nio.ByteOrder
-import java.util.UUID
-
 
 private const val ENABLE_BLUETOOTH_REQUEST_CODE = 1
-
 private const val RUNTIME_PERMISSION_REQUEST_CODE = 2
 
-// Top level declaration
-private const val GATT_MAX_MTU_SIZE = 517
-
-// Top level declaration
-private const val GATT_REQUESTED_MTU_SIZE = GATT_MAX_MTU_SIZE
-
-
-private val DEMO_SERVICE_UUID = UUID.fromString("00000000-0001-11E1-9AB4-0002A5D5C51B")
-private val DEMO_CHAR_UUID = UUID.fromString("00140000-0001-11E1-AC36-0002A5D5C51B")
-
-
 fun Context.hasPermission(permissionType: String): Boolean {
     return ContextCompat.checkSelfPermission(this, permissionType) ==
             PackageManager.PERMISSION_GRANTED
@@ -62,113 +42,26 @@ fun Context.hasRequiredRuntimePermissions(): Boolean {
     }
 }
 
-data class DemoPayload(val ts: Int, val pressure: Float, val temperature: Float)
-
-
-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
-}
-
-
-fun decodeDemoPayload(bytes: ByteArray): DemoPayload {
-    val ts = bytesToUInt16(bytes, 0)
-    val pressure = bytesToInt32(bytes, 2) / 100.0f
-    val temp = bytesToInt16(bytes, 6) / 10.0f;
-    return DemoPayload(ts, pressure, temp)
-}
-
-
 @SuppressLint("MissingPermission")
 class MainActivity : AppCompatActivity() {
 
     private lateinit var binding: ActivityMainBinding
 
-    private val scanSettings = ScanSettings.Builder()
-        .setScanMode(ScanSettings.SCAN_MODE_BALANCED)
-        .build()
-
     private val bluetoothAdapter: BluetoothAdapter by lazy {
         val bluetoothManager = getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         bluetoothManager.adapter
     }
 
-    private val bleScanner by lazy {
+
-        bluetoothAdapter.bluetoothLeScanner
+    private val connectionManager: ConnectionManager by lazy {
+        newConnectionManager()
     }
 
-    private var isScanning = false
+    private val kirbyDevices = mutableListOf<DeviceListEntry>();
-        set(value) {
+
-            field = value
+    private val deviceListAdapter: DeviceListAdapter by lazy {
-            runOnUiThread {
+        DeviceListAdapter(kirbyDevices)
-                binding.fab.setText(if (value) "Stop Scan" else "Start Scan")
     }
-        }
-
-    private val kirbyScanResults = ArrayList<ScanResult>();
-
-
-    private var mtuSizeInBytes = 23
-
-
-    private val scanResultAdapter: ScanResultAdapter by lazy {
-        ScanResultAdapter(kirbyScanResults) { scanResult ->
-            // User tapped on a scan result
-            if (isScanning) {
-                stopBleScan()
-            }
-
-            Log.i(
-                "ConnectCallback",
-                "Start connecting to ${scanResult.device} (${scanResult.device.name})"
-            )
-
-            ConnectionManager.connect(scanResult.device, applicationContext)
-            ConnectionManager.requestMtu(scanResult.device, Int.MAX_VALUE)
-            ConnectionManager.discoverServices(scanResult.device)
-            //ConnectionManager.readChar(scanResult.device, DEMO_SERVICE_UUID, DEMO_CHAR_UUID)
-            ConnectionManager.enableNotification(
-                scanResult.device,
-                DEMO_SERVICE_UUID,
-                DEMO_CHAR_UUID
-            )
-        }
-    }
-
-    private val bleListener = object : BleListener() {
-
-        fun logDemoPayload(characteristic: BluetoothGattCharacteristic) {
-            if (characteristic.service.uuid == DEMO_SERVICE_UUID && characteristic.uuid == DEMO_CHAR_UUID) {
-                val payload = decodeDemoPayload(characteristic.value)
-                Log.i("BleListener", "Demo char received: $payload")
-            }
-        }
-
-        override fun onSuccessfulCharRead(
-            gatt: BluetoothGatt,
-            characteristic: BluetoothGattCharacteristic
-        ) {
-            logDemoPayload(characteristic)
-        }
-
-        override fun onCharChange(
-            gatt: BluetoothGatt,
-            characteristic: BluetoothGattCharacteristic
-        ) {
-            logDemoPayload(characteristic)
-        }
-    }
-
 
     override fun onCreate(savedInstanceState: Bundle?) {
         WindowCompat.setDecorFitsSystemWindows(window, false)
@@ -182,37 +75,97 @@ class MainActivity : AppCompatActivity() {
 
 
         binding.fab.setOnClickListener { view ->
-            if (!isScanning) {
+            if (!hasRequiredRuntimePermissions()) {
-                startBleScan()
+                requestRelevantRuntimePermissions()
+            }
+            if (connectionManager.isScanning) {
+                connectionManager.stopScan()
             } else {
-                stopBleScan()
+                startBleScan()
             }
-//            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
-//                    .setAnchorView(R.id.fab)
-//                    .setAction("Action", null).show()
         }
 
-        setupRecyclerView()
+        setupDevicesList()
-
-        ConnectionManager.register(bleListener)
 
     }
 
-    private fun setupRecyclerView() {
+    private fun setupDevicesList() {
-        binding.scanResultsRecyclerView.apply {
+        binding.devicesList.apply {
-            adapter = scanResultAdapter
+            adapter = deviceListAdapter
             layoutManager = LinearLayoutManager(
                 this@MainActivity,
                 RecyclerView.VERTICAL,
                 false
             )
-            isNestedScrollingEnabled = false
+            //isNestedScrollingEnabled = false
         }
 
-        val animator = binding.scanResultsRecyclerView.itemAnimator
+        val animator = binding.devicesList.itemAnimator
         if (animator is SimpleItemAnimator) {
             animator.supportsChangeAnimations = false
         }
+        //addDummyDevices()
+    }
+
+    @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) {
+            override fun onScanningStateChange(isScanning: Boolean) {
+                runOnUiThread {
+                    binding.fab.setText(if (isScanning) "Stop Scan" else "Start Scan")
+                }
+            }
+
+            override fun onScanResult(callbackType: Int, result: ScanResult) {
+                if ((result.device.name ?: "").lowercase().contains("kirby")) {
+
+                    Log.i(
+                        "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 }
+                    if (kirbyDevice == null) {
+                        newKirbyDevice(callbackType, result)
+                    } else {
+                        kirbyDevice.rssi = result.rssi
+                    }
+
+                }
+            }
+        })
+        return mngr
+    }
+
+    private fun newKirbyDevice(callbackType: Int, scanResult: ScanResult): KirbyDevice {
+        val device = KirbyDevice(connectionManager, scanResult.device, scanResult.rssi) {
+            val i = kirbyDevices.indexOfFirst { d -> d === it }
+            runOnUiThread {
+                deviceListAdapter.notifyItemChanged(i)
+            }
+        }
+        connectionManager.register(device)
+        kirbyDevices.add(device)
+        device.onScanResult(callbackType, scanResult)
+        deviceListAdapter.notifyItemInserted(kirbyDevices.size - 1)
+        return device
+    }
+
+    private fun startBleScan() {
+        if (!hasRequiredRuntimePermissions()) {
+            requestRelevantRuntimePermissions()
+        } else {
+            connectionManager.startScan()
+            // kirbyDevices.clear()
+            //deviceListAdapter.notifyDataSetChanged()
+        }
     }
 
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
@@ -231,7 +184,6 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
-
     override fun onResume() {
         super.onResume()
         if (!bluetoothAdapter.isEnabled) {
@@ -296,51 +248,6 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
-    @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})"
-            )
-            if ((result.device.name ?: "").lowercase().contains("kirby")) {
-                Log.i(
-                    "ScanCallback",
-                    "Found Kirby device with name ${result.device.name} (address: ${result.device.address}, rssi: ${result.rssi})"
-                )
-                val index =
-                    kirbyScanResults.indexOfFirst { r -> r.device.address == result.device.address }
-                if (index == -1) {
-                    kirbyScanResults.add(result);
-                    scanResultAdapter.notifyItemInserted(index)
-                } else {
-                    kirbyScanResults[index] = result
-                    scanResultAdapter.notifyItemChanged(index)
-                }
-            }
-        }
-
-        override fun onScanFailed(errorCode: Int) {
-            Log.e("ScanCallback", "onScanFailed: code $errorCode")
-        }
-    }
-
-    private fun startBleScan() {
-        if (!hasRequiredRuntimePermissions()) {
-            requestRelevantRuntimePermissions()
-        } else {
-            kirbyScanResults.clear()
-            scanResultAdapter.notifyDataSetChanged()
-            bleScanner.startScan(null, scanSettings, scanCallback)
-            isScanning = true
-        }
-    }
-
-    private fun stopBleScan() {
-        bleScanner.stopScan(scanCallback)
-        isScanning = false
-    }
-
     private fun Activity.requestRelevantRuntimePermissions() {
         if (hasRequiredRuntimePermissions()) {
             return
@@ -357,8 +264,6 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun requestLocationPermission() {
-
-
         val onClick = { dialog: DialogInterface, which: Int ->
             ActivityCompat.requestPermissions(
                 this,
@@ -366,8 +271,6 @@ class MainActivity : AppCompatActivity() {
                 RUNTIME_PERMISSION_REQUEST_CODE
             )
         }
-
-
         runOnUiThread {
             val builder = AlertDialog.Builder(this)
 
@@ -389,7 +292,6 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun requestBluetoothPermissions() {
-
         val onClick = { dialog: DialogInterface, which: Int ->
             ActivityCompat.requestPermissions(
                 this,
@@ -400,8 +302,6 @@ class MainActivity : AppCompatActivity() {
                 RUNTIME_PERMISSION_REQUEST_CODE
             )
         }
-
-
         runOnUiThread {
             val builder = AlertDialog.Builder(this)
 
@@ -420,7 +320,63 @@ class MainActivity : AppCompatActivity() {
                 show()
             }
         }
-
+    }
 }
 
+@SuppressLint("MissingPermission")
+class DummyListEntry(override val address: String) : DeviceListEntry {
+
+    override var rssi: Int = 99
+
+    override val name: String = "Device 123"
+    override val status: String
+        get() = "statusA, statusB"
+
+    override fun getActions(): List<Action> {
+        return listOf(object : Action {
+            override fun getLabel(): String {
+                return "Test action 1"
+            }
+
+            override fun getIcon(): String {
+                return ""
+            }
+
+            override fun execute() {
+
+            }
+        }, object : Action {
+            override fun getLabel(): String {
+                return "Test action 2"
+            }
+
+            override fun getIcon(): String {
+                return ""
+            }
+
+            override fun execute() {
+
+            }
+        })
+    }
+
+    override fun getMeasurements(): List<Measurement> {
+        return listOf(object : Measurement {
+            override fun getLabel(): String {
+                return "Temperature"
+            }
+
+            override fun getFormattedValue(): String {
+                return "21.2 °C"
+            }
+        }, object : Measurement {
+            override fun getLabel(): String {
+                return "Pressure"
+            }
+
+            override fun getFormattedValue(): String {
+                return "232 bar"
+            }
+        })
+    }
 }

app/src/main/java/com/example/sensortestingapp/ScanResultAdapter.kt

@@ -1,64 +0,0 @@
-package com.example.sensortestingapp
-
-import android.annotation.SuppressLint
-import android.bluetooth.le.ScanResult
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
-import android.widget.TextView
-import androidx.recyclerview.widget.RecyclerView
-
-@SuppressLint("MissingPermission")
-class ScanResultAdapter(
-    private val items: List<ScanResult>,
-    private val onClickListener: ((device: ScanResult) -> Unit)
-) : RecyclerView.Adapter<ScanResultAdapter.ViewHolder>() {
-
-    /**
-     * Provide a reference to the type of views that you are using
-     * (custom ViewHolder)
-     */
-    class ViewHolder(
-        private val view: View,
-        private val onClickListener: ((device: ScanResult) -> Unit)
-    ) : RecyclerView.ViewHolder(view) {
-
-        val deviceNameView: TextView
-        val macAddressView: TextView
-        val signalStrengthView: TextView
-
-        init {
-            deviceNameView = view.findViewById(R.id.device_name)
-            macAddressView = view.findViewById(R.id.mac_address)
-            signalStrengthView = view.findViewById(R.id.signal_strength)
-        }
-
-        fun bind(result: ScanResult) {
-            deviceNameView.text = result.device.name ?: "Unnamed"
-            macAddressView.text = result.device.address
-            signalStrengthView.text = "${result.rssi} dBm"
-            view.setOnClickListener { onClickListener.invoke(result) }
-        }
-    }
-
-    override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
-        // Create a new view, which defines the UI of the list item
-        val view = LayoutInflater.from(viewGroup.context)
-            .inflate(R.layout.row_scan_result, viewGroup, false)
-
-        return ViewHolder(view, onClickListener)
-    }
-
-    override fun getItemCount() = items.size
-
-    // Replace the contents of a view (invoked by the layout manager)
-    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
-
-        // Get element from your dataset at this position and replace the
-        // contents of the view with that element
-        val item = items[position]
-        holder.bind(item)
-    }
-
-
-}

app/src/main/res/drawable/baseline_more_vert_24.xml

@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#000000"
+    android:viewportHeight="24" android:viewportWidth="24"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="@android:color/white" android:pathData="M12,8c1.1,0 2,-0.9 2,-2s-0.9,-2 -2,-2 -2,0.9 -2,2 0.9,2 2,2zM12,10c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2zM12,16c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2z"/>
+</vector>

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

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <solid android:color="#FFFFFF"/>
+    <corners android:radius="10dp"/>
+    <padding android:left="0dp" android:top="0dp" android:right="0dp" android:bottom="0dp" />
+</shape>

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

@@ -5,6 +5,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
+    android:background="@color/grey"
     tools:context=".MainActivity">
 
     <com.google.android.material.appbar.AppBarLayout
@@ -15,22 +16,20 @@
         <com.google.android.material.appbar.MaterialToolbar
             android:id="@+id/toolbar"
             android:layout_width="match_parent"
-            android:layout_height="?attr/actionBarSize" />
+            android:layout_height="?attr/actionBarSize"
-
+            style="@style/Widget.MaterialComponents.Toolbar.Primary" />
-        <androidx.recyclerview.widget.RecyclerView
-            android:id="@+id/scan_results_recycler_view"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:layout_marginTop="8dp"
-            app:layout_constraintTop_toBottomOf="@id/toolbar"
-            app:layout_constraintBottom_toBottomOf="parent"
-            app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintEnd_toEndOf="parent"
-            tools:listitem="@layout/row_scan_result" />
-
 
     </com.google.android.material.appbar.AppBarLayout>
 
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/devices_list"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior"
+        app:layoutManager="LinearLayoutManager"
+        android:layout_marginBottom="?attr/actionBarSize"
+        android:padding="10dp"
+        tools:listitem="@layout/row_device_list" />
 
     <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
         android:id="@+id/fab"
@@ -42,5 +41,4 @@
         android:text='Scan'
         app:srcCompat="@android:drawable/stat_sys_data_bluetooth" />
 
-
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -0,0 +1,103 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/device_fields"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:background="@drawable/layout_bg"
+    android:layout_width="match_parent"
+    android:layout_marginBottom="10dp"
+    android:padding="10dp"
+    android:layout_height="wrap_content">
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:id="@+id/device_meta"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_constraintTop_toTopOf="parent">
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+            android:id="@+id/name_and_actions"
+            android:layout_width="match_parent"
+            android:layout_height="50dp"
+            app:layout_constraintTop_toTopOf="parent">
+
+            <TextView
+                android:id="@+id/device_name"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:textSize="18sp"
+                android:textStyle="bold"
+                app:layout_constraintTop_toTopOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintBottom_toBottomOf="parent"
+                tools:text="Device Name" />
+
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/device_actions"
+                style="@style/Widget.MaterialComponents.Button.Icon"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                app:icon="@drawable/baseline_more_vert_24"
+                app:iconGravity="textStart"
+                app:iconPadding="-5dp"
+                app:iconSize="25dp"
+                app:layout_constraintEnd_toEndOf="parent"
+                app:layout_constraintTop_toTopOf="parent" />
+
+        </androidx.constraintlayout.widget.ConstraintLayout>
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+            android:id="@+id/address_and_rssi"
+            android:layout_width="match_parent"
+            android:layout_height="25dp"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/name_and_actions">
+
+            <TextView
+                android:id="@+id/mac_address"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:textSize="14sp"
+                app:layout_constraintTop_toTopOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                tools:text="MAC: XX:XX:XX:XX:XX" />
+
+            <TextView
+                android:id="@+id/signal_strength"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:textSize="14sp"
+                app:layout_constraintTop_toTopOf="parent"
+                app:layout_constraintEnd_toEndOf="parent"
+                tools:text="-100 dBm" />
+
+        </androidx.constraintlayout.widget.ConstraintLayout>
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+            android:id="@+id/status_container"
+            android:layout_width="match_parent"
+            android:layout_height="25dp"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/address_and_rssi">
+
+            <TextView
+                android:id="@+id/device_status"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:textSize="14sp"
+                app:layout_constraintTop_toTopOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                tools:text="Device Status" />
+        </androidx.constraintlayout.widget.ConstraintLayout>
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
+
+    <ListView
+        android:layout_marginTop="8dp"
+        android:id="@+id/measurement_fields"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:layout_constraintTop_toBottomOf="@id/device_meta" />
+
+
+</androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -3,37 +3,26 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="wrap_content"
+    android:layout_height="wrap_content">
-    android:padding="8dp"
-    android:background="?android:attr/selectableItemBackground">
 
     <TextView
-        android:id="@+id/device_name"
+        android:id="@+id/measurement_label"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:textSize="18sp"
-        android:textStyle="bold"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        tools:text="Device Name" />
+        tools:text="Temperature" />
 
     <TextView
-        android:id="@+id/mac_address"
+        android:id="@+id/measurement_value"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:textSize="14sp"
+        android:textSize="18sp"
-        app:layout_constraintTop_toBottomOf="@id/device_name"
-        app:layout_constraintStart_toStartOf="parent"
-        tools:text="MAC: XX:XX:XX:XX:XX" />
-
-    <TextView
-        android:id="@+id/signal_strength"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:textSize="14sp"
-        app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
-        tools:text="-100 dBm" />
+        app:layout_constraintTop_toTopOf="parent"
-
+        tools:text="20 °C" />
 </androidx.constraintlayout.widget.ConstraintLayout>
+
+

app/src/main/res/menu/device_menu.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:tools="http://schemas.android.com/tools"
+    tools:context="com.example.sensortestingapp.MainActivity" />

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

@@ -2,4 +2,5 @@
 <resources>
     <color name="black">#FF000000</color>
     <color name="white">#FFFFFFFF</color>
+    <color name="grey">#ECECEC</color>
 </resources>