diff --git a/example/android/app/build.gradle b/example/android/app/build.gradle
index 986ee288..6f492fc6 100644
--- a/example/android/app/build.gradle
+++ b/example/android/app/build.gradle
@@ -26,7 +26,7 @@ apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion 33
+    compileSdkVersion 34
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
diff --git a/example/lib/src/ble/ble_device_connector.dart b/example/lib/src/ble/ble_device_connector.dart
index 536ff8b0..91ac08c7 100644
--- a/example/lib/src/ble/ble_device_connector.dart
+++ b/example/lib/src/ble/ble_device_connector.dart
@@ -19,7 +19,7 @@ class BleDeviceConnector extends ReactiveState<ConnectionStateUpdate> {
   final _deviceConnectionController = StreamController<ConnectionStateUpdate>();
 
   // ignore: cancel_subscriptions
-  late StreamSubscription<ConnectionStateUpdate> _connection;
+  StreamSubscription<ConnectionStateUpdate>? _connection;
 
   Future<void> connect(String deviceId) async {
     _logMessage('Start connecting to $deviceId');
@@ -37,7 +37,7 @@ class BleDeviceConnector extends ReactiveState<ConnectionStateUpdate> {
   Future<void> disconnect(String deviceId) async {
     try {
       _logMessage('disconnecting to device: $deviceId');
-      await _connection.cancel();
+      await _connection?.cancel();
     } on Exception catch (e, _) {
       _logMessage("Error disconnecting from a device: $e");
     } finally {
diff --git a/example/lib/src/ui/device_detail/characteristic_interaction_dialog.dart b/example/lib/src/ui/device_detail/characteristic_interaction_dialog.dart
index 17f09231..98fd0301 100644
--- a/example/lib/src/ui/device_detail/characteristic_interaction_dialog.dart
+++ b/example/lib/src/ui/device_detail/characteristic_interaction_dialog.dart
@@ -35,7 +35,7 @@ class _CharacteristicInteractionDialogState extends State<_CharacteristicInterac
   late String writeOutput;
   late String subscribeOutput;
   late TextEditingController textEditingController;
-  late StreamSubscription<List<int>>? subscribeStream;
+  StreamSubscription<List<int>>? subscribeStream;
 
   @override
   void initState() {
diff --git a/example/lib/src/ui/device_detail/device_interaction_tab.dart b/example/lib/src/ui/device_detail/device_interaction_tab.dart
index 02a2fb98..1759713f 100644
--- a/example/lib/src/ui/device_detail/device_interaction_tab.dart
+++ b/example/lib/src/ui/device_detail/device_interaction_tab.dart
@@ -285,7 +285,7 @@ class _ServiceDiscoveryListState extends State<_ServiceDiscoveryList> {
             child: ExpansionPanelList(
               expansionCallback: (int index, bool isExpanded) {
                 setState(() {
-                  if (isExpanded) {
+                  if (!isExpanded) {
                     _expandedItems.remove(index);
                   } else {
                     _expandedItems.add(index);