diff --git a/AGENTS.md b/AGENTS.md
index dfba093..128ce01 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -19,7 +19,8 @@ ESP32-S3-PICO-1-N8R8 (Atom S3R Voice), 2 relais, 2 touch sensors (JR223B), BLE,
 
 - PlatformIO, `platform = espressif32@6.7.0`, board `esp32-s3-devkitc-1`
 - CDC USB serial (`ARDUINO_USB_CDC_ON_BOOT=1`), QIO OPI flash
-- Upload laptop: `pio run -t upload`, port `/dev/ttyACM0`, 115200 baud
+- **Upload:** `pio run -t upload` (via `--no-stub`, OPI flash vereist dit). Poort: **NOOIT `/dev/ttyACM0`** (dat is het Atreus toetsenbord). ESP32 herkennen via `ls /dev/serial/by-id/ | grep -i espressif` en die poort gebruiken. PlatformIO: pas `upload_port` in `platformio.ini` aan naar de gevonden poort.
+- **Direct flashen (handmatig):** `~/.platformio/packages/tool-esptoolpy/esptool.py --no-stub --chip esp32s3 --port /dev/ttyACM1 --baud 115200 --before default_reset --after hard_reset write_flash --flash_mode keep --flash_size keep 0x0 .pio/build/m5stack-atoms3r/bootloader.bin 0x8000 .pio/build/m5stack-atoms3r/partitions.bin 0xE000 ~/.platformio/packages/framework-arduinoespressif32/tools/partitions/boot_app0.bin 0x10000 .pio/build/m5stack-atoms3r/firmware.bin`
 - NVS: namespace "hmac", key "key" (32 bytes HMAC)
 - BLE advertising "SylDa_Server", HMAC-verified relay commands
 
diff --git a/android/app/build.gradle b/android/app/build.gradle
index 3e3b80c..4331f86 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -11,7 +11,7 @@ android {
     // compileSdk/targetSdk stays on 34 (Android 14) by deliberate choice. The target audience
     // consists of physically disabled users who are very reluctant to update their phones. Staying
     // on API 34 maximises device compatibility. Re-evaluate when the user base has migrated.
-    compileSdk 36
+    compileSdk 34
 
     if (hasSigningConfig) {
         def props = new Properties()
@@ -30,7 +30,7 @@ android {
     defaultConfig {
         applicationId "nl.eddydevink.sylda"
         minSdk 26
-        targetSdk 36
+        targetSdk 34
         versionCode 1
         versionName "1.0"
         buildConfigField "String", "BUILD_NUMBER", "\"${new java.text.SimpleDateFormat("yyyyMMddHHmmss").format(new Date())}\""
diff --git a/android/app/src/main/assets/firmware/firmware.bin b/android/app/src/main/assets/firmware/firmware.bin
index 9c849f5..b8d28b7 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/nl/eddydevink/sylda/MainActivity.kt b/android/app/src/main/java/nl/eddydevink/sylda/MainActivity.kt
index 23e4f4e..87cb207 100644
--- a/android/app/src/main/java/nl/eddydevink/sylda/MainActivity.kt
+++ b/android/app/src/main/java/nl/eddydevink/sylda/MainActivity.kt
@@ -23,7 +23,7 @@ class MainActivity : AppCompatActivity(), BleCallbacks {
         private const val REQUEST_SETTINGS = 1
         private const val POST_SETTINGS_RESCAN_MS = 500L
         private const val ON_RESUME_SCAN_DELAY_MS = 300L
-        private const val BUNDLED_FIRMWARE_VERSION = "5"
+        private const val BUNDLED_FIRMWARE_VERSION = "6"
     }
 
     private lateinit var manager: BleRelayManager
diff --git a/android/app/src/main/java/nl/eddydevink/sylda/SettingsActivity.kt b/android/app/src/main/java/nl/eddydevink/sylda/SettingsActivity.kt
index 10d810d..59ea230 100644
--- a/android/app/src/main/java/nl/eddydevink/sylda/SettingsActivity.kt
+++ b/android/app/src/main/java/nl/eddydevink/sylda/SettingsActivity.kt
@@ -64,7 +64,7 @@ class SettingsActivity : AppCompatActivity() {
         private const val REBOOT_WAIT_MS = 5000L
         private const val REBOOT_POLL_MS = 500L
         private const val REBOOT_MAX_WAIT_MS = 15000L
-        private const val EXPECTED_FIRMWARE_VERSION = "5"
+        private const val EXPECTED_FIRMWARE_VERSION = "6"
     }
 
     private enum class UsbAction { NONE, EXCHANGE_KEY, FLASH }
diff --git a/android/app/src/main/res/layout/activity_main.xml b/android/app/src/main/res/layout/activity_main.xml
index 730ca59..1219dc9 100644
--- a/android/app/src/main/res/layout/activity_main.xml
+++ b/android/app/src/main/res/layout/activity_main.xml
@@ -2,77 +2,69 @@
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:fitsSystemWindows="true">
-
-    <FrameLayout
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:padding="16dp">
+    android:padding="16dp">
 
         <LinearLayout
             android:id="@+id/settingsContainer"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_gravity="end|top"
-            android:layout_marginTop="8dp"
             android:orientation="horizontal"
             android:gravity="center_vertical"
             android:background="?android:attr/selectableItemBackground"
             android:clickable="true"
             android:focusable="true">
 
-            <TextView
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="@string/settings_label"
-                android:textSize="14sp"
-                android:layout_marginEnd="4dp" />
-
-            <ImageButton
-                android:id="@+id/settingsButton"
-                android:layout_width="40dp"
-                android:layout_height="40dp"
-                android:src="@drawable/ic_settings"
-                android:background="?android:attr/selectableItemBackgroundBorderless"
-                android:contentDescription="@string/cd_settings" />
-        </LinearLayout>
-
-        <LinearLayout
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_gravity="center"
-            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:textAllCaps="false"
-                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:textAllCaps="false"
-                android:enabled="false" />
-
-        </LinearLayout>
-
         <TextView
-            android:id="@+id/statusText"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:layout_gravity="bottom|start"
-            android:text="@string/status_default"
-            android:textSize="14sp" />
+            android:text="@string/settings_label"
+            android:textSize="14sp"
+            android:layout_marginEnd="4dp" />
 
-    </FrameLayout>
+        <ImageButton
+            android:id="@+id/settingsButton"
+            android:layout_width="40dp"
+            android:layout_height="40dp"
+            android:src="@drawable/ic_settings"
+            android:background="?android:attr/selectableItemBackgroundBorderless"
+            android:contentDescription="@string/cd_settings" />
+    </LinearLayout>
 
-</FrameLayout>
+    <LinearLayout
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        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:textAllCaps="false"
+            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:textAllCaps="false"
+            android:enabled="false" />
+
+    </LinearLayout>
+
+    <TextView
+        android:id="@+id/statusText"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|start"
+        android:text="@string/status_default"
+        android:textSize="14sp" />
+
+</FrameLayout>
\ No newline at end of file
diff --git a/android/app/src/main/res/layout/activity_settings.xml b/android/app/src/main/res/layout/activity_settings.xml
index 7e4321a..abd743c 100644
--- a/android/app/src/main/res/layout/activity_settings.xml
+++ b/android/app/src/main/res/layout/activity_settings.xml
@@ -3,147 +3,138 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
-    android:fitsSystemWindows="true">
+    android:padding="24dp">
+
+    <RadioGroup
+        android:id="@+id/flashMethodGroup"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:layout_marginBottom="8dp"
+        android:checkedButton="@id/methodBluetooth">
+
+        <RadioButton
+            android:id="@+id/methodBluetooth"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:gravity="center"
+            android:text="@string/method_bluetooth" />
+
+        <RadioButton
+            android:id="@+id/methodUsb"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:gravity="center"
+            android:text="@string/method_usb" />
+    </RadioGroup>
+
+    <Button
+        android:id="@+id/updateModuleButton"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/button_update_module" />
+
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="1dp"
+        android:background="?android:attr/listDivider"
+        android:layout_marginTop="24dp"
+        android:layout_marginBottom="16dp" />
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/section_labels"
+        android:textSize="14sp"
+        android:textStyle="bold"
+        android:layout_marginBottom="8dp" />
 
     <LinearLayout
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:orientation="vertical"
-        android:padding="24dp"
-        android:layout_marginTop="8dp">
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:layout_marginBottom="16dp">
 
-        <RadioGroup
-            android:id="@+id/flashMethodGroup"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:orientation="horizontal"
-            android:layout_marginBottom="8dp"
-            android:checkedButton="@id/methodBluetooth">
-
-            <RadioButton
-                android:id="@+id/methodBluetooth"
-                android:layout_width="0dp"
-                android:layout_height="wrap_content"
-                android:layout_weight="1"
-                android:gravity="center"
-                android:text="@string/method_bluetooth" />
-
-            <RadioButton
-                android:id="@+id/methodUsb"
-                android:layout_width="0dp"
-                android:layout_height="wrap_content"
-                android:layout_weight="1"
-                android:gravity="center"
-                android:text="@string/method_usb" />
-        </RadioGroup>
-
-        <Button
-            android:id="@+id/updateModuleButton"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:text="@string/button_update_module" />
-
-        <View
-            android:layout_width="match_parent"
-            android:layout_height="1dp"
-            android:background="?android:attr/listDivider"
-            android:layout_marginTop="24dp"
-            android:layout_marginBottom="16dp" />
-
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:text="@string/section_labels"
-            android:textSize="14sp"
-            android:textStyle="bold"
-            android:layout_marginBottom="8dp" />
-
-        <LinearLayout
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:orientation="horizontal"
-            android:layout_marginBottom="16dp">
-
-            <EditText
-                android:id="@+id/labelRelay1"
-                android:layout_width="0dp"
-                android:layout_height="wrap_content"
-                android:layout_weight="1"
-                android:hint="@string/hint_label_relay1"
-                android:maxLines="1"
-                android:inputType="text"
-                android:imeOptions="actionDone"
-                android:gravity="center" />
-
-            <EditText
-                android:id="@+id/labelRelay2"
-                android:layout_width="0dp"
-                android:layout_height="wrap_content"
-                android:layout_weight="1"
-                android:hint="@string/hint_label_relay2"
-                android:maxLines="1"
-                android:inputType="text"
-                android:imeOptions="actionDone"
-                android:gravity="center" />
-        </LinearLayout>
-
-        <View
-            android:layout_width="match_parent"
-            android:layout_height="1dp"
-            android:background="?android:attr/listDivider"
-            android:layout_marginBottom="16dp" />
-
-        <TextView
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:text="@string/section_theme"
-            android:textSize="14sp"
-            android:textStyle="bold"
-            android:layout_marginBottom="8dp" />
-
-        <LinearLayout
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:orientation="horizontal"
-            android:weightSum="3">
-
-            <RadioGroup
-                android:id="@+id/themeGroup"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content"
-                android:orientation="horizontal">
-
-                <RadioButton
-                    android:id="@+id/themeSystem"
-                    android:layout_width="0dp"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:gravity="center"
-                    android:text="@string/theme_system" />
-
-                <RadioButton
-                    android:id="@+id/themeLight"
-                    android:layout_width="0dp"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:gravity="center"
-                    android:text="@string/theme_light" />
-
-                <RadioButton
-                    android:id="@+id/themeDark"
-                    android:layout_width="0dp"
-                    android:layout_height="wrap_content"
-                    android:layout_weight="1"
-                    android:gravity="center"
-                    android:text="@string/theme_dark" />
-            </RadioGroup>
-        </LinearLayout>
-
-        <View
+        <EditText
+            android:id="@+id/labelRelay1"
             android:layout_width="0dp"
-            android:layout_height="0dp"
-            android:layout_weight="1" />
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:hint="@string/hint_label_relay1"
+            android:maxLines="1"
+            android:inputType="text"
+            android:imeOptions="actionDone"
+            android:gravity="center" />
 
+        <EditText
+            android:id="@+id/labelRelay2"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:hint="@string/hint_label_relay2"
+            android:maxLines="1"
+            android:inputType="text"
+            android:imeOptions="actionDone"
+            android:gravity="center" />
     </LinearLayout>
 
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="1dp"
+        android:background="?android:attr/listDivider"
+        android:layout_marginBottom="16dp" />
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/section_theme"
+        android:textSize="14sp"
+        android:textStyle="bold"
+        android:layout_marginBottom="8dp" />
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:weightSum="3">
+
+        <RadioGroup
+            android:id="@+id/themeGroup"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="horizontal">
+
+            <RadioButton
+                android:id="@+id/themeSystem"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:gravity="center"
+                android:text="@string/theme_system" />
+
+            <RadioButton
+                android:id="@+id/themeLight"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:gravity="center"
+                android:text="@string/theme_light" />
+
+            <RadioButton
+                android:id="@+id/themeDark"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:gravity="center"
+                android:text="@string/theme_dark" />
+        </RadioGroup>
+    </LinearLayout>
+
+    <View
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        android:layout_weight="1" />
+
 </LinearLayout>
diff --git a/platformio.ini b/platformio.ini
index 4f488bb..11bd9a7 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -14,4 +14,5 @@ build_flags =
 lib_deps =
     h2zero/NimBLE-Arduino@^2
 upload_port = /dev/ttyACM1
-upload_speed = 115200
\ No newline at end of file
+upload_speed = 115200
+upload_flags = --no-stub
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index c8f2568..8062e2e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -35,7 +35,7 @@
 #define NVS_NAMESPACE "hmac"
 #define NVS_KEY_NAME  "key"
 #define NVS_UUID_NAME "uuid"
-#define FIRMWARE_VERSION "5"
+#define FIRMWARE_VERSION "6"
 
 NimBLECharacteristic *pCharacteristic;
 bool deviceConnected = false;
@@ -338,8 +338,8 @@ void setup() {
     }
     Serial.println("LED blink done, starting BLE...");
 
-    NimBLEDevice::setMTU(512);
     NimBLEDevice::init("SylDa_Server");
+    NimBLEDevice::setMTU(248);
 
     NimBLEServer *pServer = NimBLEDevice::createServer();
     pServer->setCallbacks(new MyServerCallbacks());