feat: add device UUID pairing — unique identity per ESP-phone pair

- Firmware: auto-generate 16-byte UUID on first boot (NVS), new READ characteristic
- BLE name: AtomS3R-Relay → SylDa_Server
- KEY? now returns DEVICE_ID + HMAC_KEY, SET_ID command for UUID provisioning
- App: UUID+HMAC loaded from prefs, scan by service UUID, verify UUID after connect
- UUID mismatch → disconnect + skip address + rescan
- Key conflict dialog: keep ESP keys, overwrite ESP (with checkbox confirm), or cancel
- NO_KEY with existing app keys: send existing pair instead of generating new
- Added design spec doc

android/app/src/main/java/com/eddy/atomrelay/EspFlasher.kt

@@ -78,6 +78,12 @@ class EspFlasher(private val context: Context) {
             val bootApp0 = assets.open("firmware/boot_app0.bin").readBytes()
             val firmware = assets.open("firmware/firmware.bin").readBytes()
 
+            // Flash sectie layout (partition table check):
+            // NVS      0x9000-0xDFFF  — NIET overschreven (key/UUID blijft behouden)
+            // otadata  0xE000-0xFFFF  — overschreven door boot_app0
+            // app0     0x10000-...    — firmware overschrijft
+            // Alleen schrijven naar benodigde adressen, geen full erase
+
             val steps = listOf(
                 FlashStep("Bootloader", 0x0, bootloader, 30, 10, false),
                 FlashStep("Partitie tabel", 0x8000, partitions, 40, 10, false),
@@ -105,9 +111,6 @@ class EspFlasher(private val context: Context) {
             callback.onProgress(20, "Stub laden...")
             val stub = detected.loadStub()
 
-            callback.onProgress(25, "Flash wissen...")
-            stub.eraseFlash()
-
             for (step in steps) {
                 coroutineContext.ensureActive()
                 val sizeStr = if (step.data.size > 1024) "${step.data.size / 1024}KB" else "${step.data.size} bytes"

android/app/src/main/java/com/eddy/atomrelay/MainActivity.kt

@@ -11,13 +11,16 @@ import android.bluetooth.BluetoothGattCharacteristic
 import android.bluetooth.BluetoothGattDescriptor
 import android.bluetooth.BluetoothProfile
 import android.bluetooth.le.ScanCallback
+import android.bluetooth.le.ScanFilter
 import android.bluetooth.le.ScanResult
+import android.bluetooth.le.ScanSettings
 import android.content.Context
 import android.content.Intent
 import android.content.pm.PackageManager
 import android.os.Bundle
 import android.os.Handler
 import android.os.Looper
+import android.os.ParcelUuid
 import android.util.Log
 import android.view.MotionEvent
 import android.widget.Button
@@ -37,42 +40,52 @@ class MainActivity : AppCompatActivity() {
         private const val TAG = "AtomRelay"
         private val SERVICE_UUID: UUID = UUID.fromString("4fafc201-1fb5-459e-8fcc-c5c9c331914b")
         private val CHARACTERISTIC_UUID: UUID = UUID.fromString("beb5483e-36e1-4688-b7f5-ea07361f26d8")
+        private val UUID_CHAR_UUID: UUID = UUID.fromString("beb5483e-36e1-4688-b7f5-ea07361f26d9")
         private val CCCD_UUID: UUID = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb")
-        private const val DEVICE_NAME = "AtomS3R-Relay"
+        private const val DEVICE_NAME = "SylDa_Server"
         private const val HMAC_PKT_SIZE = 37
         private const val HMAC_LEN = 32
         private const val REQUEST_SETTINGS = 1
-        private const val SCAN_TIMEOUT_MS = 10000L
+        private const val SCAN_TIMEOUT_MS = 30000L
         private const val RECONNECT_DELAY_MS = 2000L
         private const val POST_SETTINGS_RESCAN_MS = 500L
         private const val ON_RESUME_SCAN_DELAY_MS = 300L
+        private const val MAX_SCAN_RETRIES = 3
     }
 
     private var bluetoothGatt: BluetoothGatt? = null
     private var relayCharacteristic: BluetoothGattCharacteristic? = null
     private var isScanning = false
     private var scanTimedOut = false
+    private var scanTimeoutRetries = 0
     private val handler = Handler(Looper.getMainLooper())
     private val scanRunnable = Runnable { startScan() }
+    private var scanTimeoutRunnable: Runnable? = null
 
     private var seq = 1
     private var hmacKey: ByteArray? = null
+    private var deviceUuid: ByteArray? = null
+    private var triedAddresses = mutableSetOf<String>()
     private var lastTheme: String? = null
 
     private lateinit var statusText: TextView
-    private lateinit var relayButton: Button
+    private lateinit var relay1Button: Button
+    private lateinit var relay2Button: Button
 
     private val scanCallback = object : ScanCallback() {
         override fun onScanResult(callbackType: Int, result: ScanResult) {
             val device = result.device
+            val address = device?.address ?: return
             val name = device?.name ?: ""
-            Log.d(TAG, "Found device: $name (${device?.address})")
+            Log.d(TAG, "Found device: $name ($address)")
-            if (name == DEVICE_NAME) {
+            if (triedAddresses.contains(address)) {
+                Log.d(TAG, "Skipping already-tried device $address")
+                return
+            }
             stopScan()
             connectToDevice(device)
         }
     }
-    }
 
     private val gattCallback = object : BluetoothGattCallback() {
         @SuppressLint("MissingPermission")
@@ -81,6 +94,12 @@ class MainActivity : AppCompatActivity() {
                 Log.w(TAG, "GATT connection state change error: status=$status newState=$newState")
             }
             if (newState == BluetoothProfile.STATE_CONNECTED) {
+                if (hmacKey == null) {
+                    Log.w(TAG, "GATT connected but no key — disconnecting")
+                    runOnUiThread { statusText.text = getString(R.string.status_no_key) }
+                    gatt.disconnect()
+                    return
+                }
                 Log.d(TAG, "GATT connected")
                 bluetoothGatt = gatt
                 runOnUiThread { statusText.text = getString(R.string.status_discovering_services) }
@@ -89,7 +108,8 @@ class MainActivity : AppCompatActivity() {
                 Log.d(TAG, "GATT disconnected")
                 runOnUiThread {
                     statusText.text = getString(R.string.status_connecting)
-                    relayButton.isEnabled = false
+                    relay1Button.isEnabled = false
+                    relay2Button.isEnabled = false
                 }
                 gatt.close()
                 bluetoothGatt = null
@@ -119,16 +139,13 @@ class MainActivity : AppCompatActivity() {
             val service = gatt.getService(SERVICE_UUID)
             if (service != null) {
                 relayCharacteristic = service.getCharacteristic(CHARACTERISTIC_UUID)
-                if (relayCharacteristic != null) {
+                val uuidChar = service.getCharacteristic(UUID_CHAR_UUID)
-                    gatt.setCharacteristicNotification(relayCharacteristic, true)
+                if (relayCharacteristic != null && uuidChar != null) {
-                    val descriptor = relayCharacteristic!!.getDescriptor(CCCD_UUID)
+                    Log.d(TAG, "Reading device UUID characteristic...")
-                    descriptor.value = BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE
+                    gatt.readCharacteristic(uuidChar)
-                    gatt.writeDescriptor(descriptor)
+                } else {
-                    Log.d(TAG, "Ready, relay characteristic found")
+                    Log.e(TAG, "Service or characteristics not found")
-                    runOnUiThread {
+                    runOnUiThread { statusText.text = getString(R.string.status_service_not_found) }
-                        statusText.text = getString(R.string.status_connected)
-                        relayButton.isEnabled = true
-                    }
                 }
             } else {
                 Log.e(TAG, "Service not found")
@@ -136,6 +153,34 @@ class MainActivity : AppCompatActivity() {
             }
         }
 
+        @SuppressLint("MissingPermission")
+        override fun onCharacteristicRead(gatt: BluetoothGatt, characteristic: BluetoothGattCharacteristic, value: ByteArray, status: Int) {
+            if (characteristic.uuid == UUID_CHAR_UUID && status == BluetoothGatt.GATT_SUCCESS) {
+                val storedUuid = deviceUuid
+                if (storedUuid != null && value.contentEquals(storedUuid)) {
+                    Log.d(TAG, "UUID verified, setting up relay")
+                    relayCharacteristic?.let { rc ->
+                        gatt.setCharacteristicNotification(rc, true)
+                        val descriptor = rc.getDescriptor(CCCD_UUID)
+                        descriptor.value = BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE
+                        gatt.writeDescriptor(descriptor)
+                    }
+                    runOnUiThread {
+                        setupRelayButton()
+                        setupRelay2Button()
+                        statusText.text = getString(R.string.status_connected)
+                        relay1Button.isEnabled = true
+                        relay2Button.isEnabled = true
+                    }
+                } else {
+                    Log.w(TAG, "UUID mismatch — disconnecting")
+                    triedAddresses.add(gatt.device.address)
+                    runOnUiThread { statusText.text = getString(R.string.status_wrong_device) }
+                    gatt.disconnect()
+                }
+            }
+        }
+
         @SuppressLint("MissingPermission")
         override fun onCharacteristicWrite(gatt: BluetoothGatt, characteristic: BluetoothGattCharacteristic, status: Int) {
             if (status == BluetoothGatt.GATT_SUCCESS) {
@@ -154,13 +199,15 @@ class MainActivity : AppCompatActivity() {
         setContentView(R.layout.activity_main)
 
         statusText = findViewById(R.id.statusText)
-        relayButton = findViewById(R.id.relayButton)
+        relay1Button = findViewById(R.id.relay1Button)
+        relay2Button = findViewById(R.id.relay2Button)
         val settingsButton = findViewById<ImageButton>(R.id.settingsButton)
 
         settingsButton.setOnClickListener {
             startActivityForResult(Intent(this, SettingsActivity::class.java), REQUEST_SETTINGS)
         }
         setupRelayButton()
+        setupRelay2Button()
     }
 
     @Deprecated("Deprecated in Java")
@@ -172,6 +219,7 @@ class MainActivity : AppCompatActivity() {
             bluetoothGatt = null
             relayCharacteristic = null
             seq = 1
+            triedAddresses.clear()
             loadState()
             handler.postDelayed(scanRunnable, POST_SETTINGS_RESCAN_MS)
         }
@@ -186,9 +234,10 @@ class MainActivity : AppCompatActivity() {
             return
         }
         loadState()
-        if (hmacKey == null) {
+        if (hmacKey == null || deviceUuid == null) {
             statusText.text = getString(R.string.status_no_key)
         } else if (!isScanning && bluetoothGatt == null) {
+            triedAddresses.clear()
             handler.postDelayed(scanRunnable, ON_RESUME_SCAN_DELAY_MS)
         }
     }
@@ -203,8 +252,10 @@ class MainActivity : AppCompatActivity() {
         val prefs = PrefsHelper.getPrefs(this)
         val hexKey = prefs.getString(PrefsHelper.PREF_KEY, null)
         hmacKey = hexKey?.let { hexStringToBytes(it) }
+        val hexUuid = prefs.getString(PrefsHelper.PREF_UUID, null)
+        deviceUuid = hexUuid?.let { hexStringToBytes(it) }
         seq = prefs.getInt(PrefsHelper.PREF_SEQ, 1).coerceAtMost(PrefsHelper.SEQ_MAX)
-        Log.d(TAG, "HMAC key loaded: ${if (hmacKey != null) "${hmacKey!!.size} bytes" else "none"}, seq=$seq")
+        Log.d(TAG, "HMAC key loaded: ${if (hmacKey != null) "${hmacKey!!.size} bytes" else "none"}, UUID: ${if (deviceUuid != null) "${deviceUuid!!.size} bytes" else "none"}, seq=$seq")
     }
 
     private fun hexStringToBytes(hex: String): ByteArray? {
@@ -240,24 +291,45 @@ class MainActivity : AppCompatActivity() {
                 startScan()
             } else {
                 statusText.text = getString(R.string.status_permissions_denied)
-                relayButton.isEnabled = false
+                relay1Button.isEnabled = false
+                relay2Button.isEnabled = false
             }
         }
     }
 
     private fun setupRelayButton() {
-        relayButton.setOnClickListener(null)
+        relay1Button.setOnClickListener(null)
-        relayButton.text = getString(R.string.button_hold)
+        relay1Button.text = getString(R.string.button_hold)
-        relayButton.setOnTouchListener { _, event ->
+        relay1Button.setOnTouchListener { _, event ->
             when (event.action) {
                 MotionEvent.ACTION_DOWN -> {
-                    sendRelayCommand(true)
+                    sendRelayCommand(0x01.toByte())
-                    relayButton.text = getString(R.string.button_on)
+                    relay1Button.text = getString(R.string.button_on)
                     true
                 }
                 MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
-                    sendRelayCommand(false)
+                    sendRelayCommand(0x00.toByte())
-                    relayButton.text = getString(R.string.button_hold)
+                    relay1Button.text = getString(R.string.button_hold)
+                    true
+                }
+                else -> false
+            }
+        }
+    }
+
+    private fun setupRelay2Button() {
+        relay2Button.setOnClickListener(null)
+        relay2Button.text = getString(R.string.button_hold)
+        relay2Button.setOnTouchListener { _, event ->
+            when (event.action) {
+                MotionEvent.ACTION_DOWN -> {
+                    sendRelayCommand(0x02.toByte())
+                    relay2Button.text = getString(R.string.button_on)
+                    true
+                }
+                MotionEvent.ACTION_UP, MotionEvent.ACTION_CANCEL -> {
+                    sendRelayCommand(0x03.toByte())
+                    relay2Button.text = getString(R.string.button_hold)
                     true
                 }
                 else -> false
@@ -279,7 +351,7 @@ class MainActivity : AppCompatActivity() {
             return
         }
 
-        if (hmacKey == null) {
+        if (hmacKey == null || deviceUuid == null) {
             statusText.text = getString(R.string.status_no_key)
             return
         }
@@ -287,31 +359,49 @@ class MainActivity : AppCompatActivity() {
         isScanning = true
         scanTimedOut = false
         statusText.text = getString(R.string.status_scanning)
-        Log.d(TAG, "Starting BLE scan for $DEVICE_NAME")
+        Log.d(TAG, "Starting BLE scan with service UUID filter")
 
-        adapter.bluetoothLeScanner.startScan(scanCallback)
+        val filter = ScanFilter.Builder().setServiceUuid(ParcelUuid(SERVICE_UUID)).build()
+        val settings = ScanSettings.Builder().setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY).build()
+        adapter.bluetoothLeScanner.startScan(listOf(filter), settings, scanCallback)
 
-        handler.postDelayed({
+        scanTimeoutRunnable?.let { handler.removeCallbacks(it) }
+        scanTimeoutRunnable = Runnable {
             if (isScanning) {
                 scanTimedOut = true
                 stopScan()
             }
-        }, SCAN_TIMEOUT_MS)
+        }
+        handler.postDelayed(scanTimeoutRunnable!!, SCAN_TIMEOUT_MS)
     }
 
     @SuppressLint("MissingPermission")
     private fun stopScan() {
         if (!isScanning) return
         isScanning = false
+        scanTimeoutRunnable?.let { handler.removeCallbacks(it) }
         val adapter = BluetoothAdapter.getDefaultAdapter()
         adapter?.bluetoothLeScanner?.stopScan(scanCallback)
         if (scanTimedOut) {
+            if (scanTimeoutRetries < MAX_SCAN_RETRIES) {
+                scanTimeoutRetries++
+                Log.d(TAG, "Scan timeout, retry $scanTimeoutRetries/$MAX_SCAN_RETRIES")
+                statusText.text = getString(R.string.status_scanning)
+                handler.postDelayed(scanRunnable, 2000L)
+                return
+            }
             statusText.text = getString(R.string.status_device_not_found)
-            relayButton.setOnTouchListener(null)
+            relay1Button.setOnTouchListener(null)
-            relayButton.text = getString(R.string.button_retry_scan)
+            relay2Button.setOnTouchListener(null)
-            relayButton.isEnabled = true
+            relay1Button.setOnClickListener(null)
-            relayButton.setOnClickListener {
+            relay2Button.setOnClickListener(null)
+            relay1Button.text = getString(R.string.button_retry_scan)
+            relay2Button.text = getString(R.string.button_hold)
+            relay2Button.isEnabled = false
+            relay1Button.isEnabled = true
+            relay1Button.setOnClickListener {
                 setupRelayButton()
+                setupRelay2Button()
                 startScan()
             }
         }
@@ -325,12 +415,11 @@ class MainActivity : AppCompatActivity() {
     }
 
     @SuppressLint("MissingPermission")
-    private fun sendRelayCommand(on: Boolean) {
+    private fun sendRelayCommand(cmd: Byte) {
         val char = relayCharacteristic ?: return
         val gatt = bluetoothGatt ?: return
         val key = hmacKey ?: return
 
-        val cmd: Byte = if (on) 0x01 else 0x00
         val packet = buildPacket(cmd, key)
         char.value = packet
         // WRITE_TYPE_NO_RESPONSE is intentional. Previously, WRITE_TYPE_DEFAULT (with ACK) was
@@ -345,7 +434,7 @@ class MainActivity : AppCompatActivity() {
         seq++
         if (seq > PrefsHelper.SEQ_MAX) seq = 1
         PrefsHelper.getPrefs(this).edit().putInt(PrefsHelper.PREF_SEQ, seq).apply()
-        Log.d(TAG, "Sent relay ${if (on) "ON" else "OFF"} (seq=${seq - 1})")
+        Log.d(TAG, "Sent relay cmd 0x${cmd.toString(16)} (seq=${seq - 1})")
     }
 
     private fun getRequiredPermissions(): Array<String> {

android/app/src/main/java/com/eddy/atomrelay/PrefsHelper.kt

@@ -13,6 +13,7 @@ object PrefsHelper {
     private const val TAG = "PrefsHelper"
     const val PREFS_NAME = "relay_prefs"
     const val PREF_KEY = "hmac_key"
+    const val PREF_UUID = "device_uuid"
     const val PREF_SEQ = "seq_counter"
     const val PREF_THEME = "theme"
     const val SEQ_MAX = 1_000_000

android/app/src/main/java/com/eddy/atomrelay/SettingsActivity.kt

@@ -18,12 +18,14 @@ import android.os.Handler
 import android.os.Looper
 import android.util.Log
 import android.widget.Button
+import android.widget.CheckBox
 import android.widget.ProgressBar
 import android.widget.RadioGroup
 import android.widget.TextView
 import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.withContext
@@ -220,19 +222,30 @@ class SettingsActivity : AppCompatActivity() {
     private fun doKeyExchange(usbManager: UsbManager, device: UsbDevice) {
         showProgressDialog(getString(R.string.title_key_exchange), getString(R.string.msg_reading_key), STYLE_SPINNER)
 
+        val prefs = PrefsHelper.getPrefs(this)
+        val appUuid = prefs.getString(PrefsHelper.PREF_UUID, null)
+        val appKey = prefs.getString(PrefsHelper.PREF_KEY, null)
+
         lifecycleScope.launch(Dispatchers.IO) {
-            val result = readKeyFromEsp(usbManager, device)
+            val result = readKeyFromEsp(usbManager, device, appUuid, appKey)
             withContext(Dispatchers.Main) {
                 if (isFinishing || isDestroyed) return@withContext
+                progressDialog?.dismiss()
+                progressDialog = null
                 when (result) {
                     is KeyResult.Success -> {
-                        val prefs = PrefsHelper.getPrefs(this@SettingsActivity)
+                        prefs.edit()
-                        prefs.edit().putString(PrefsHelper.PREF_KEY, result.hexKey).apply()
+                            .putString(PrefsHelper.PREF_UUID, result.deviceUuid)
+                            .putString(PrefsHelper.PREF_KEY, result.hexKey)
+                            .apply()
                         Toast.makeText(this@SettingsActivity, getString(R.string.key_read_success), Toast.LENGTH_LONG).show()
                         cleanupAction()
                         setResult(RESULT_SCAN)
                         finish()
                     }
+                    is KeyResult.Conflict -> {
+                        showConflictDialog(usbManager, device, result.espUuid, result.espKey, appKey ?: "")
+                    }
                     is KeyResult.Error -> {
                         Toast.makeText(this@SettingsActivity, getString(R.string.key_exchange_failed), Toast.LENGTH_LONG).show()
                         cleanupAction()
@@ -385,11 +398,12 @@ class SettingsActivity : AppCompatActivity() {
     // === ESP Key Exchange via USB ===
 
     sealed class KeyResult {
-        data class Success(val hexKey: String) : KeyResult()
+        data class Success(val deviceUuid: String, val hexKey: String) : KeyResult()
+        data class Conflict(val espUuid: String, val espKey: String) : KeyResult()
         data class Error(val message: String) : KeyResult()
     }
 
-    private fun readKeyFromEsp(usbManager: UsbManager, device: UsbDevice): KeyResult? {
+    private fun readKeyFromEsp(usbManager: UsbManager, device: UsbDevice, appUuid: String?, appKey: String?): KeyResult? {
         val intf = UsbUtils.findCdcDataInterface(device)
             ?: return KeyResult.Error("Geen CDC interface gevonden")
 
@@ -428,18 +442,36 @@ class SettingsActivity : AppCompatActivity() {
                 Log.d(TAG, "Attempt $attempt response: ${response.take(300)}")
 
                 val keyLine = response.lines().firstOrNull { it.startsWith("HMAC_KEY:") }
+                val uuidLine = response.lines().firstOrNull { it.startsWith("DEVICE_ID:") }
                 val noKey = response.lines().any { it.trim() == "NO_KEY" }
 
-                if (keyLine != null) {
+                if (keyLine != null && uuidLine != null) {
                     val hexKey = keyLine.removePrefix("HMAC_KEY:").trim()
-                    if (hexKey.length == 64 && hexKey.all { it in "0123456789ABCDEFabcdef" }) {
+                    val hexUuid = uuidLine.removePrefix("DEVICE_ID:").trim()
-                        return KeyResult.Success(hexKey.uppercase())
+                    if (hexKey.length == 64 && hexKey.all { it in "0123456789ABCDEFabcdef" } &&
+                        hexUuid.length == 32 && hexUuid.all { it in "0123456789ABCDEFabcdef" }) {
+                        val espKeyUpper = hexKey.uppercase()
+                        val espUuidUpper = hexUuid.uppercase()
+                        if (appUuid != null && appKey != null &&
+                            (appUuid != espUuidUpper || appKey != espKeyUpper)) {
+                            return KeyResult.Conflict(espUuidUpper, espKeyUpper)
+                        }
+                        return KeyResult.Success(espUuidUpper, espKeyUpper)
                     } else {
-                        return KeyResult.Error("Ongeldig sleutel formaat (lengte=${hexKey.length})")
+                        return KeyResult.Error("Ongeldig sleutel/UUID formaat")
                     }
                 } else if (noKey) {
-                    Log.d(TAG, "ESP has no key, provisioning new one")
+                    val newKey: String
-                    val newKey = generateRandomHexKey()
+                    val newUuid: String
+                    if (appUuid != null && appKey != null) {
+                        Log.d(TAG, "ESP has no keys, using existing app keys")
+                        newKey = appKey
+                        newUuid = appUuid
+                    } else {
+                        Log.d(TAG, "Both have no keys, generating new pair")
+                        newKey = generateRandomHexKey()
+                        newUuid = generateRandomHex(16)
+                    }
 
                     val setKeyCmd = "SET_KEY:$newKey\n".toByteArray(StandardCharsets.US_ASCII)
                     val w = connection.bulkTransfer(epOut, setKeyCmd, setKeyCmd.size, USB_BULK_TIMEOUT_MS)
@@ -449,15 +481,29 @@ class SettingsActivity : AppCompatActivity() {
                     }
 
                     Thread.sleep(RESPONSE_WAIT_MS)
+                    val okKeyResponse = readResponse(connection, epIn, SET_KEY_TIMEOUT_MS)
+                    Log.d(TAG, "SET_KEY response: ${okKeyResponse.take(200)}")
 
-                    val okResponse = readResponse(connection, epIn, SET_KEY_TIMEOUT_MS)
+                    if (!okKeyResponse.contains("OK")) {
-                    Log.d(TAG, "SET_KEY response: ${okResponse.take(200)}")
-
-                    if (okResponse.contains("OK")) {
-                        return KeyResult.Success(newKey)
-                    } else {
                         return KeyResult.Error("ESP bevestigde sleutel niet")
                     }
+
+                    val setIdCmd = "SET_ID:$newUuid\n".toByteArray(StandardCharsets.US_ASCII)
+                    val w2 = connection.bulkTransfer(epOut, setIdCmd, setIdCmd.size, USB_BULK_TIMEOUT_MS)
+                    Log.d(TAG, "Sent SET_ID ($w2 bytes)")
+                    if (w2 < 0) {
+                        return KeyResult.Error("SET_ID schrijven mislukt")
+                    }
+
+                    Thread.sleep(RESPONSE_WAIT_MS)
+                    val okUuidResponse = readResponse(connection, epIn, SET_KEY_TIMEOUT_MS)
+                    Log.d(TAG, "SET_ID response: ${okUuidResponse.take(200)}")
+
+                    if (okUuidResponse.contains("OK")) {
+                        return KeyResult.Success(newUuid, newKey)
+                    } else {
+                        return KeyResult.Error("ESP bevestigde UUID niet")
+                    }
                 }
 
                 Log.w(TAG, "Attempt $attempt: no KEY response, retrying")
@@ -490,7 +536,7 @@ class SettingsActivity : AppCompatActivity() {
             val len = connection.bulkTransfer(epIn, buf, buf.size, READ_CHUNK_TIMEOUT_MS)
             if (len > 0) {
                 sb.append(String(buf, 0, len, StandardCharsets.US_ASCII))
-                if ((sb.contains("HMAC_KEY:") || sb.contains("NO_KEY") || sb.contains("OK")) && sb.contains("\n")) {
+                if ((sb.contains("HMAC_KEY:") || sb.contains("NO_KEY") || sb.contains("OK") || sb.contains("ERROR")) && sb.contains("\n")) {
                     break
                 }
             }
@@ -539,4 +585,145 @@ class SettingsActivity : AppCompatActivity() {
         random.nextBytes(bytes)
         return bytes.joinToString("") { "%02X".format(it) }
     }
+
+    private fun generateRandomHex(byteCount: Int): String {
+        val random = SecureRandom()
+        val bytes = ByteArray(byteCount)
+        random.nextBytes(bytes)
+        return bytes.joinToString("") { "%02X".format(it) }
+    }
+
+    private fun showConflictDialog(usbManager: UsbManager, device: UsbDevice,
+                                   espUuid: String, espKey: String, appKey: String) {
+        val prefs = PrefsHelper.getPrefs(this)
+        val appUuid = prefs.getString(PrefsHelper.PREF_UUID, "") ?: ""
+
+        AlertDialog.Builder(this)
+            .setTitle(getString(R.string.title_key_conflict))
+            .setMessage(getString(R.string.msg_key_conflict))
+            .setPositiveButton(getString(R.string.button_keep_esp_keys)) { _, _ ->
+                prefs.edit()
+                    .putString(PrefsHelper.PREF_UUID, espUuid)
+                    .putString(PrefsHelper.PREF_KEY, espKey)
+                    .apply()
+                Toast.makeText(this, getString(R.string.key_read_success), Toast.LENGTH_LONG).show()
+                cleanupAction()
+                setResult(RESULT_SCAN)
+                finish()
+            }
+            .setNegativeButton(getString(R.string.button_overwrite_esp)) { _, _ ->
+                showOverwriteConfirmDialog(usbManager, device, espUuid, espKey, appKey, appUuid)
+            }
+            .setNeutralButton(getString(R.string.button_cancel)) { _, _ ->
+                cleanupAction()
+            }
+            .setCancelable(false)
+            .show()
+    }
+
+    private fun showOverwriteConfirmDialog(usbManager: UsbManager, device: UsbDevice,
+                                           espUuid: String, espKey: String,
+                                           appKey: String, appUuid: String) {
+        val view = layoutInflater.inflate(R.layout.dialog_overwrite_confirm, null)
+        val checkBox = view.findViewById<CheckBox>(R.id.confirmCheckBox)
+        val dialog = AlertDialog.Builder(this)
+            .setTitle(getString(R.string.title_overwrite_confirm))
+            .setView(view)
+            .setPositiveButton(getString(R.string.button_confirm)) { _, _ ->
+                if (checkBox.isChecked) {
+                    doOverwriteEspKeys(usbManager, device, appKey, appUuid)
+                }
+            }
+            .setNegativeButton(getString(R.string.button_cancel)) { _, _ -> }
+            .setCancelable(true)
+            .show()
+        dialog.getButton(AlertDialog.BUTTON_POSITIVE).isEnabled = false
+        checkBox.setOnCheckedChangeListener { _, isChecked ->
+            dialog.getButton(AlertDialog.BUTTON_POSITIVE).isEnabled = isChecked
+        }
+    }
+
+    private fun doOverwriteEspKeys(usbManager: UsbManager, device: UsbDevice,
+                                   appKey: String, appUuid: String) {
+        showProgressDialog(getString(R.string.title_overwriting_keys), getString(R.string.msg_writing_keys), STYLE_SPINNER)
+
+        lifecycleScope.launch(Dispatchers.IO) {
+            val result = writeKeysToEsp(usbManager, device, appKey, appUuid)
+            withContext(Dispatchers.Main) {
+                if (isFinishing || isDestroyed) return@withContext
+                progressDialog?.dismiss()
+                progressDialog = null
+                when (result) {
+                    is KeyResult.Success -> {
+                        Toast.makeText(this@SettingsActivity, getString(R.string.key_read_success), Toast.LENGTH_LONG).show()
+                        cleanupAction()
+                        setResult(RESULT_SCAN)
+                        finish()
+                    }
+                    is KeyResult.Error -> {
+                        Toast.makeText(this@SettingsActivity, result.message, Toast.LENGTH_LONG).show()
+                        cleanupAction()
+                    }
+                    else -> {
+                        Toast.makeText(this@SettingsActivity, getString(R.string.key_exchange_failed), Toast.LENGTH_SHORT).show()
+                        cleanupAction()
+                    }
+                }
+            }
+        }
+    }
+
+    private fun writeKeysToEsp(usbManager: UsbManager, device: UsbDevice,
+                                appKey: String, appUuid: String): KeyResult? {
+        val intf = UsbUtils.findCdcDataInterface(device)
+            ?: return KeyResult.Error("Geen CDC interface gevonden")
+
+        val connection = usbManager.openDevice(device)
+            ?: return KeyResult.Error("Kan USB apparaat niet openen")
+
+        if (!connection.claimInterface(intf, true)) {
+            connection.close()
+            return KeyResult.Error("Kan USB interface niet claimen")
+        }
+
+        val epOut = UsbUtils.findBulkEndpoint(intf, UsbConstants.USB_DIR_OUT)
+            ?: run { connection.close(); return KeyResult.Error("Geen USB OUT endpoint gevonden") }
+        val epIn = UsbUtils.findBulkEndpoint(intf, UsbConstants.USB_DIR_IN)
+            ?: run { connection.close(); return KeyResult.Error("Geen USB IN endpoint gevonden") }
+
+        try {
+            setupCdcControl(connection, device)
+            Thread.sleep(KEY_SETTLE_MS)
+            flushReadBuffer(connection, epIn)
+
+            val setKeyCmd = "SET_KEY:$appKey\n".toByteArray(StandardCharsets.US_ASCII)
+            val w = connection.bulkTransfer(epOut, setKeyCmd, setKeyCmd.size, USB_BULK_TIMEOUT_MS)
+            if (w < 0) return KeyResult.Error("SET_KEY schrijven mislukt")
+            Log.d(TAG, "Sent SET_KEY ($w bytes)")
+
+            Thread.sleep(RESPONSE_WAIT_MS)
+            val okKeyResponse = readResponse(connection, epIn, SET_KEY_TIMEOUT_MS)
+            if (!okKeyResponse.contains("OK")) return KeyResult.Error("ESP bevestigde sleutel niet")
+
+            val setIdCmd = "SET_ID:$appUuid\n".toByteArray(StandardCharsets.US_ASCII)
+            val w2 = connection.bulkTransfer(epOut, setIdCmd, setIdCmd.size, USB_BULK_TIMEOUT_MS)
+            if (w2 < 0) return KeyResult.Error("SET_ID schrijven mislukt")
+
+            Thread.sleep(RESPONSE_WAIT_MS)
+            val okUuidResponse = readResponse(connection, epIn, SET_KEY_TIMEOUT_MS)
+            if (!okUuidResponse.contains("OK")) return KeyResult.Error("ESP bevestigde UUID niet")
+
+            val prefs = PrefsHelper.getPrefs(this)
+            prefs.edit()
+                .putString(PrefsHelper.PREF_UUID, appUuid)
+                .putString(PrefsHelper.PREF_KEY, appKey)
+                .apply()
+            return KeyResult.Success(appUuid, appKey)
+        } catch (e: Exception) {
+            Log.e(TAG, "Write keys error", e)
+            return KeyResult.Error("Fout: ${e.message}")
+        } finally {
+            try { connection.close() } catch (_: Exception) {}
+        }
+    }
 }

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

@@ -13,15 +13,32 @@
         android:background="?android:attr/selectableItemBackgroundBorderless"
         android:contentDescription="Instellingen" />
 
-    <Button
+    <LinearLayout
-        android:id="@+id/relayButton"
+        android:layout_width="wrap_content"
-        android:layout_width="200dp"
+        android:layout_height="wrap_content"
-        android:layout_height="200dp"
         android:layout_gravity="center"
-        android:text="HOLD"
+        android:orientation="horizontal"
+        android:gravity="center">
+
+        <Button
+            android:id="@+id/relay1Button"
+            android:layout_width="150dp"
+            android:layout_height="200dp"
+            android:text="1"
             android:textSize="24sp"
             android:enabled="false" />
 
+        <Button
+            android:id="@+id/relay2Button"
+            android:layout_width="150dp"
+            android:layout_height="200dp"
+            android:layout_marginStart="16dp"
+            android:text="2"
+            android:textSize="24sp"
+            android:enabled="false" />
+
+    </LinearLayout>
+
     <TextView
         android:id="@+id/statusText"
         android:layout_width="wrap_content"

android/app/src/main/res/layout/dialog_overwrite_confirm.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="20dp">
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/msg_overwrite_warning"
+        android:textSize="14sp"
+        android:paddingBottom="16dp" />
+
+    <CheckBox
+        android:id="@+id/confirmCheckBox"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/checkbox_confirm_overwrite" />
+
+</LinearLayout>

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

@@ -15,6 +15,7 @@
     <string name="status_bluetooth_disabled">Bluetooth not enabled</string>
     <string name="status_scanning">Scanning…</string>
     <string name="status_device_not_found">Device not found</string>
+    <string name="status_wrong_device">Verkeerd apparaat — opnieuw scannen…</string>
     <string name="button_retry_scan">Opnieuw scannen</string>
 
     <!-- MainActivity UI -->
@@ -29,6 +30,20 @@
     <string name="key_exchange_failed">Sleutel uitwisselen mislukt - probeer opnieuw</string>
     <string name="flash_failed">Flashen mislukt: %s</string>
 
+    <!-- Key conflict dialog -->
+    <string name="title_key_conflict">Sleutels komen niet overeen</string>
+    <string name="msg_key_conflict">De ESP (SylDa_Server) heeft andere sleutels dan deze app. Wat wil je doen?</string>
+    <string name="button_keep_esp_keys">ESP sleutels overnemen</string>
+    <string name="button_overwrite_esp">App sleutels overzetten</string>
+    <string name="button_confirm">Bevestigen</string>
+
+    <!-- Overwrite confirmation dialog -->
+    <string name="title_overwrite_confirm">ESP sleutels overschrijven?</string>
+    <string name="msg_overwrite_warning">Dit vervangt de sleutels van de ESP. De ESP kan daarna niet meer met de oorspronkelijke app communiceren.</string>
+    <string name="checkbox_confirm_overwrite">Ik weet het zeker</string>
+    <string name="title_overwriting_keys">Sleutels overschrijven</string>
+    <string name="msg_writing_keys">Sleutels schrijven naar ESP…</string>
+
     <!-- SettingsActivity dialogs -->
     <string name="title_key_exchange">Sleutel Uitwisselen</string>
     <string name="title_firmware_flash">Firmware Flashen</string>

src/main.cpp

@@ -7,26 +7,36 @@
 #include <mbedtls/md.h>
 #include <Preferences.h>
 
-#define SENSOR_PIN 38
+#define RELAY1_PIN  1
-#define RELAY_PIN  1
+#define RELAY2_PIN  2
+#define TOUCH1_PIN  8
+#define TOUCH2_PIN  6
+#define BUTTON_PIN  41
 #define LED_PIN     46
 
 #define SERVICE_UUID        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
 #define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361f26d8"
+#define UUID_CHAR_UUID      "beb5483e-36e1-4688-b7f5-ea07361f26d9"
 
 #define HMAC_PKT_SIZE 37   // 1 cmd + 4 seq + 32 hmac
 #define HMAC_KEY_LEN  32
+#define ESP_UUID_LEN  16
 #define NVS_NAMESPACE "hmac"
 #define NVS_KEY_NAME  "key"
+#define NVS_UUID_NAME "uuid"
 
 BLECharacteristic *pCharacteristic;
 bool deviceConnected = false;
-bool bleCommand = false;
+bool bleRelay1 = false;
-bool relayState = false;
+bool bleRelay2 = false;
+bool relay1State = false;
+bool relay2State = false;
 uint32_t lastSeq = 0;
 
 uint8_t hmacKey[HMAC_KEY_LEN];
+uint8_t deviceUuid[ESP_UUID_LEN];
 bool keyProvisioned = false;
+bool uuidProvisioned = false;
 Preferences preferences;
 
 class MyServerCallbacks : public BLEServerCallbacks {
@@ -37,7 +47,8 @@ class MyServerCallbacks : public BLEServerCallbacks {
     }
     void onDisconnect(BLEServer *pServer) override {
         deviceConnected = false;
-        bleCommand = false;
+        bleRelay1 = false;
+        bleRelay2 = false;
         lastSeq = 0;
         Serial.println("BLE: device disconnected");
         BLEDevice::startAdvertising();
@@ -109,23 +120,29 @@ class MyCharacteristicCallbacks : public BLECharacteristicCallbacks {
         uint32_t seq = lastSeq;
 
         if (cmd == 0x01) {
-            bleCommand = true;
+            bleRelay1 = true;
-            Serial.printf("BLE: relay ON (seq=%lu)\n", seq);
+            Serial.printf("BLE: relay1 ON (seq=%lu)\n", seq);
-        } else {
+        } else if (cmd == 0x00) {
-            bleCommand = false;
+            bleRelay1 = false;
-            Serial.printf("BLE: relay OFF (seq=%lu)\n", seq);
+            Serial.printf("BLE: relay1 OFF (seq=%lu)\n", seq);
+        } else if (cmd == 0x02) {
+            bleRelay2 = true;
+            Serial.printf("BLE: relay2 ON (seq=%lu)\n", seq);
+        } else if (cmd == 0x03) {
+            bleRelay2 = false;
+            Serial.printf("BLE: relay2 OFF (seq=%lu)\n", seq);
         }
     }
 };
 
 void setup() {
-    delay(2000);
     Serial.begin(115200);
-    delay(500);
+    delay(2000);
     Serial.println("=== Atom VoiceS3R BLE Relay ===");
 
     preferences.begin(NVS_NAMESPACE, true);
     size_t len = preferences.getBytes(NVS_KEY_NAME, hmacKey, HMAC_KEY_LEN);
+    size_t uuidLen = preferences.getBytes(NVS_UUID_NAME, deviceUuid, ESP_UUID_LEN);
     preferences.end();
 
     if (len == HMAC_KEY_LEN) {
@@ -136,8 +153,28 @@ void setup() {
         Serial.println("No HMAC key provisioned — connect USB and run SET_KEY");
     }
 
-    pinMode(SENSOR_PIN, INPUT_PULLUP);
+    if (uuidLen == ESP_UUID_LEN) {
-    pinMode(RELAY_PIN, OUTPUT);
+        uuidProvisioned = true;
+        Serial.print("UUID loaded from NVS: ");
+        for (int i = 0; i < ESP_UUID_LEN; i++) Serial.printf("%02X", deviceUuid[i]);
+        Serial.println();
+    } else {
+        uuidProvisioned = false;
+        for (int i = 0; i < ESP_UUID_LEN; i++) deviceUuid[i] = (uint8_t)(esp_random() & 0xFF);
+        preferences.begin(NVS_NAMESPACE, false);
+        preferences.putBytes(NVS_UUID_NAME, deviceUuid, ESP_UUID_LEN);
+        preferences.end();
+        uuidProvisioned = true;
+        Serial.print("Generated new UUID: ");
+        for (int i = 0; i < ESP_UUID_LEN; i++) Serial.printf("%02X", deviceUuid[i]);
+        Serial.println();
+    }
+
+    pinMode(TOUCH1_PIN, INPUT_PULLUP);
+    pinMode(TOUCH2_PIN, INPUT_PULLUP);
+    pinMode(BUTTON_PIN, INPUT);
+    pinMode(RELAY1_PIN, OUTPUT);
+    pinMode(RELAY2_PIN, OUTPUT);
     pinMode(LED_PIN, OUTPUT);
 
     for (int i = 0; i < 3; i++) {
@@ -148,7 +185,7 @@ void setup() {
     }
     Serial.println("LED blink done, starting BLE...");
 
-    BLEDevice::init("AtomS3R-Relay");
+    BLEDevice::init("SylDa_Server");
 
     BLEServer *pServer = BLEDevice::createServer();
     pServer->setCallbacks(new MyServerCallbacks());
@@ -164,6 +201,12 @@ void setup() {
     pCharacteristic->setValue("0");
     pService->start();
 
+    BLECharacteristic *pUuidChar = pService->createCharacteristic(
+        UUID_CHAR_UUID,
+        BLECharacteristic::PROPERTY_READ
+    );
+    pUuidChar->setValue(deviceUuid, ESP_UUID_LEN);
+
     BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
     pAdvertising->addServiceUUID(SERVICE_UUID);
     pAdvertising->setScanResponse(true);
@@ -171,7 +214,7 @@ void setup() {
     pAdvertising->setMinPreferred(0x12);
     BLEDevice::startAdvertising();
 
-    Serial.println("BLE: advertising started as 'AtomS3R-Relay'");
+    Serial.println("BLE: advertising started as 'SylDa_Server'");
 
     if (keyProvisioned) {
         Serial.print("HMAC Key: ");
@@ -194,7 +237,10 @@ void loop() {
         if (c == '\n') {
             serialBuf.trim();
             if (serialBuf == "KEY?") {
-                if (keyProvisioned) {
+                if (keyProvisioned && uuidProvisioned) {
+                    Serial.print("DEVICE_ID:");
+                    for (int i = 0; i < ESP_UUID_LEN; i++) Serial.printf("%02X", deviceUuid[i]);
+                    Serial.println();
                     Serial.print("HMAC_KEY:");
                     for (int i = 0; i < HMAC_KEY_LEN; i++) {
                         Serial.printf("%02X", hmacKey[i]);
@@ -217,35 +263,77 @@ void loop() {
                 } else {
                     Serial.println("ERROR: invalid key format");
                 }
+            } else if (serialBuf.startsWith("SET_ID:")) {
+                String hex = serialBuf.substring(7);
+                hex.toUpperCase();
+                if (hex.length() == 32 && isHexKey(hex)) {
+                    for (int i = 0; i < ESP_UUID_LEN; i++) {
+                        deviceUuid[i] = (uint8_t)strtoul(hex.substring(i * 2, i * 2 + 2).c_str(), nullptr, 16);
+                    }
+                    preferences.begin(NVS_NAMESPACE, false);
+                    preferences.putBytes(NVS_UUID_NAME, deviceUuid, ESP_UUID_LEN);
+                    preferences.end();
+                    uuidProvisioned = true;
+                    Serial.println("OK");
+                    Serial.println("UUID stored in NVS");
+                } else {
+                    Serial.println("ERROR: invalid UUID format");
+                }
             }
             serialBuf = "";
         }
     }
 
-    int sensorState = digitalRead(SENSOR_PIN);
+    static bool t1Stable = false;
+    static bool t2Stable = false;
+    static bool btnStable = false;
+    static uint32_t t1Change = 0;
+    static uint32_t t2Change = 0;
+    static uint32_t btnChange = 0;
+    #define DEBOUNCE_MS 50
+    bool t1Raw = (digitalRead(TOUCH1_PIN) == LOW);
+    bool t2Raw = (digitalRead(TOUCH2_PIN) == LOW);
+    bool btnRaw = (digitalRead(BUTTON_PIN) == LOW);
+    if (t1Raw != t1Stable) { t1Change = millis(); t1Stable = t1Raw; }
+    if (t2Raw != t2Stable) { t2Change = millis(); t2Stable = t2Raw; }
+    if (btnRaw != btnStable) { btnChange = millis(); btnStable = btnRaw; }
+    bool t1Active = (millis() - t1Change > DEBOUNCE_MS) && t1Stable;
+    bool t2Active = (millis() - t2Change > DEBOUNCE_MS) && t2Stable;
+    bool btnActive = (millis() - btnChange > DEBOUNCE_MS) && btnStable;
 
-    bool touchActive = (sensorState == LOW);
+    relay1State = t1Active || btnActive || (deviceConnected && bleRelay1);
-    bool bleActive = (deviceConnected && bleCommand);
+    relay2State = t2Active || (deviceConnected && bleRelay2);
 
-    relayState = touchActive || bleActive;
+    digitalWrite(RELAY1_PIN, relay1State ? HIGH : LOW);
+    digitalWrite(RELAY2_PIN, relay2State ? HIGH : LOW);
 
-    digitalWrite(RELAY_PIN, relayState ? HIGH : LOW);
+    digitalWrite(LED_PIN, (relay1State || relay2State) ? HIGH : LOW);
 
-    static bool lastRelay = false;
+    static bool lastRelay1 = false;
-    if (relayState != lastRelay) {
+    static bool lastRelay2 = false;
-        Serial.printf("Relay %s (touch=%s, ble=%s)\n",
+    if (relay1State != lastRelay1 || relay2State != lastRelay2) {
-            relayState ? "ON" : "OFF",
+        Serial.printf("Relays: R1=%s R2=%s (t1=%s t2=%s btn=%s ble1=%s ble2=%s)\n",
-            sensorState == LOW ? "YES" : "no",
+            relay1State ? "ON" : "OFF",
-            deviceConnected ? "connected" : "disconnected");
+            relay2State ? "ON" : "OFF",
-        lastRelay = relayState;
+            t1Active ? "YES" : "no",
+            t2Active ? "YES" : "no",
+            btnActive ? "YES" : "no",
+            bleRelay1 ? "ON" : "OFF",
+            bleRelay2 ? "ON" : "OFF");
+        lastRelay1 = relay1State;
+        lastRelay2 = relay2State;
     }
 
     static uint32_t heartbeat = 0;
     if (millis() - heartbeat > 5000) {
-        Serial.printf("[heartbeat] relay=%s touch=%s ble=%s\n",
+        Serial.printf("[heartbeat] R1=%s R2=%s t1=%s t2=%s btn=%s ble1=%s ble2=%s\n",
-            relayState ? "ON" : "OFF",
+            relay1State ? "ON" : "OFF",
-            sensorState == LOW ? "YES" : "no",
+            relay2State ? "ON" : "OFF",
-            deviceConnected ? "connected" : "disconnected");
+            t1Active ? "YES" : "no",
+            t2Active ? "YES" : "no",
+            btnActive ? "YES" : "no",
+            bleRelay1 ? "ON" : "OFF",
+            bleRelay2 ? "ON" : "OFF");
         heartbeat = millis();
     }