diff --git a/android/app/src/main/assets/firmware/firmware.bin b/android/app/src/main/assets/firmware/firmware.bin
index aad7d4e..e5bf28e 100644
Binary files a/android/app/src/main/assets/firmware/firmware.bin and b/android/app/src/main/assets/firmware/firmware.bin differ
diff --git a/android/app/src/main/java/com/eddy/atomrelay/MainActivity.kt b/android/app/src/main/java/com/eddy/atomrelay/MainActivity.kt
index b6cb3a8..08321f0 100644
--- a/android/app/src/main/java/com/eddy/atomrelay/MainActivity.kt
+++ b/android/app/src/main/java/com/eddy/atomrelay/MainActivity.kt
@@ -213,7 +213,7 @@ class MainActivity : AppCompatActivity() {
     @Deprecated("Deprecated in Java")
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
         super.onActivityResult(requestCode, resultCode, data)
-        if (requestCode == REQUEST_SETTINGS && resultCode == Activity.RESULT_OK) {
+        if (requestCode == REQUEST_SETTINGS && resultCode == SettingsActivity.RESULT_SCAN) {
             stopScan()
             bluetoothGatt?.close()
             bluetoothGatt = null
@@ -260,7 +260,7 @@ class MainActivity : AppCompatActivity() {
 
     private fun hexStringToBytes(hex: String): ByteArray? {
         val cleaned = hex.uppercase().filter { it in "0123456789ABCDEF" }
-        if (cleaned.length != 64) return null
+        if (cleaned.isEmpty() || cleaned.length % 2 != 0) return null
         return cleaned.chunked(2).map { it.toInt(16).toByte() }.toByteArray()
     }
 
diff --git a/src/main.cpp b/src/main.cpp
index 77c60fb..ffb428c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,5 +1,6 @@
 #include <Arduino.h>
 #include <NimBLEDevice.h>
+#include <NimBLEAdvertising.h>
 
 #include <mbedtls/md.h>
 #include <Preferences.h>
@@ -202,13 +203,19 @@ void setup() {
     pUuidChar->setValue(deviceUuid, ESP_UUID_LEN);
 
     NimBLEAdvertising *pAdvertising = NimBLEDevice::getAdvertising();
+    pAdvertising->setName("SylDa_Server");
     pAdvertising->addServiceUUID(SERVICE_UUID);
+
+    NimBLEAdvertisementData scanResp;
+    scanResp.setCompleteServices(NimBLEUUID(SERVICE_UUID));
+    pAdvertising->setScanResponseData(scanResp);
     pAdvertising->enableScanResponse(true);
+
     pAdvertising->setMinInterval(32);
     pAdvertising->setMaxInterval(64);
-    NimBLEDevice::startAdvertising();
-
-    Serial.println("BLE: advertising started as 'SylDa_Server'");
+    bool advOk = pAdvertising->start();
+    Serial.printf("BLE: advertising started as 'SylDa_Server' (start=%d, isAdv=%d)\n",
+                  advOk, pAdvertising->isAdvertising());
 
     if (keyProvisioned) {
         Serial.print("HMAC Key: ");