diff --git a/app/(tabs)/explore.tsx b/app/(tabs)/explore.tsx
index cb8ba9e..4eb8430 100644
--- a/app/(tabs)/explore.tsx
+++ b/app/(tabs)/explore.tsx
@@ -30,6 +30,7 @@ export default function TabTwoScreen() {
         updateActivationTime,
         sendIdentityCheck,
         transferSampleFile,
+        transferEmptyTestPackage,
     } = useBleExplorer();
 
 
@@ -166,6 +167,11 @@ export default function TabTwoScreen() {
                         onPress={transferSampleFile}
                         disabled={!isConnected || loading.transferring}
                     />
+                    <Button
+                        title={loading.transferring ? 'Transferring...' : 'Transfer Test'}
+                        onPress={transferEmptyTestPackage}
+                        disabled={!isConnected || loading.transferring}
+                    />
                 </ThemedView>
             </ThemedView>
 
diff --git a/ble/core/BleClient.ts b/ble/core/BleClient.ts
index d3e992c..4d76ea7 100644
--- a/ble/core/BleClient.ts
+++ b/ble/core/BleClient.ts
@@ -95,9 +95,11 @@ export class BleClient {
                 autoConnect: false,
                 requestMTU: BLE_UUIDS.REQUEST_MTU
             });
-            if (device.mtu !== BLE_UUIDS.REQUEST_MTU) {
+            if (device.mtu < BLE_UUIDS.REQUEST_MTU) {
                 console.log("MTU not supported, requesting default to ", BLE_UUIDS.REQUEST_MTU);
-                device = await device.requestMTU(BLE_UUIDS.REQUEST_MTU)
+                device = await device.requestMTU(BLE_UUIDS.REQUEST_MTU);
+                // Give some time for the stack to stabilize after MTU change
+                await new Promise(resolve => setTimeout(resolve, 500));
             }
             console.log("Connected to device with MTU = ", device.mtu);
             this.connectedDevice = await device.discoverAllServicesAndCharacteristics();
diff --git a/ble/hooks/useBleExplorer.ts b/ble/hooks/useBleExplorer.ts
index 37d3512..df9e2fb 100644
--- a/ble/hooks/useBleExplorer.ts
+++ b/ble/hooks/useBleExplorer.ts
@@ -456,6 +456,19 @@ export const useBleExplorer = () => {
         }
     }, [state.connectedDevice, fileTransferService, convertToANI, setError]);
 
+    const transferEmptyTestPackage = useCallback(async () => {
+        if (!state.connectedDevice) {
+            setError('No device connected');
+            return;
+        }
+        await fileTransferService.transferTestPackage(
+            state.connectedDevice.id,
+            (progress) => {
+                setState(prev => ({...prev, transferProgress: progress * 100}));
+            }
+        )
+    }, [fileTransferService, setError, state.connectedDevice])
+
     const clearLogs = useCallback(() => setState(prev => ({...prev, logs: []})), []);
 
     return {
@@ -468,6 +481,7 @@ export const useBleExplorer = () => {
         queryDeviceVersion,
         queryActivationStatus,
         transferSampleFile,
+        transferEmptyTestPackage,
         clearLogs,
         updateActivationTime: () => {
         },
diff --git a/ble/protocol/ProtocolManager.ts b/ble/protocol/ProtocolManager.ts
index 47f3535..16451a1 100644
--- a/ble/protocol/ProtocolManager.ts
+++ b/ble/protocol/ProtocolManager.ts
@@ -28,19 +28,20 @@ export class ProtocolManager {
         type: COMMAND_TYPES,
         data: Uint8Array,
         head: FRAME_HEAD = FRAME_CONSTANTS.HEAD_APP_TO_DEVICE,
-        requireFragmentation: boolean = true
+        requireFragmentation: boolean = true,
+        maxDataSize: number = FRAME_CONSTANTS.MAX_DATA_SIZE
     ): Uint8Array[] {
         // Max pages index is 4 bytes, so we can fit up to 65535 pages of data
-        const maxDataSize = 0xffff * (FRAME_CONSTANTS.HEADER_SIZE + FRAME_CONSTANTS.MAX_DATA_SIZE + FRAME_CONSTANTS.FOOTER_SIZE);
-        if (data.length > maxDataSize) {
-            throw new Error(`Data size ${data.length} exceeds max size ${maxDataSize}`);
+        const maxTotalSize = 0xffff * (FRAME_CONSTANTS.HEADER_SIZE + maxDataSize + FRAME_CONSTANTS.FOOTER_SIZE);
+        if (data.length > maxTotalSize) {
+            throw new Error(`Data size ${data.length} exceeds max size ${maxTotalSize}`);
         }
-        if (data.length <= FRAME_CONSTANTS.MAX_DATA_SIZE || !requireFragmentation) {
-            console.debug(`[ProtocolManager] Frame size ${data.length} is less than max size ${FRAME_CONSTANTS.MAX_DATA_SIZE}, not fragmented`);
+        if (data.length <= maxDataSize || !requireFragmentation) {
+            console.debug(`[ProtocolManager] Frame size ${data.length} is less than max size ${maxDataSize}, not fragmented`);
             return [this.createSingleFrame(type, data, head)];
         } else {
-            console.debug(`[ProtocolManager] Frame size ${data.length} is greater than max size ${FRAME_CONSTANTS.MAX_DATA_SIZE}, fragmented`);
-            return this.createFragmentedFrames(type, data, head);
+            console.debug(`[ProtocolManager] Frame size ${data.length} is greater than max size ${maxDataSize}, fragmented`);
+            return this.createFragmentedFrames(type, data, head, maxDataSize);
         }
     }
 
@@ -62,6 +63,8 @@ export class ProtocolManager {
         // dataLen
         buffer[offset++] = (data.length >> 8) & 0xff;
         buffer[offset++] = data.length & 0xff;
+        const hexHeader = Array.from(buffer.slice(0, offset)).map(b => b.toString(16).padStart(2, '0')).join(' ');
+        console.debug(`chunk length = ${data.length}, buffer 8 header = ${hexHeader}`)
 
         // data
         buffer.set(data, offset);
@@ -75,10 +78,9 @@ export class ProtocolManager {
         return buffer;
     }
 
-    private static createFragmentedFrames(type: COMMAND_TYPES, data: Uint8Array, head: FRAME_HEAD): Uint8Array[] {
+    private static createFragmentedFrames(type: COMMAND_TYPES, data: Uint8Array, head: FRAME_HEAD, maxDataSize: number): Uint8Array[] {
         const frames: Uint8Array[] = [];
         const totalSize = data.length;
-        const maxDataSize = FRAME_CONSTANTS.MAX_DATA_SIZE;
         const totalPages = Math.ceil(totalSize / maxDataSize);
 
         for (let i = 0; i < totalPages; i++) {
@@ -112,8 +114,7 @@ export class ProtocolManager {
             offset += chunk.length;
 
             buffer[offset] = this.calculateChecksum(buffer.slice(0, offset));
-            const verify = this.verifyChecksum(buffer.slice(0, offset), buffer[offset]);
-            console.debug(`[ProtocolManager] Verify checksum: ${verify}`);
+
             frames.push(buffer);
         }
 
diff --git a/ble/services/BleProtocolService.ts b/ble/services/BleProtocolService.ts
index e3957b7..679e039 100644
--- a/ble/services/BleProtocolService.ts
+++ b/ble/services/BleProtocolService.ts
@@ -148,7 +148,16 @@ export class BleProtocolService {
             payload = new Uint8Array(Buffer.from(jsonStr));
         }
 
-        const frames = ProtocolManager.createFrame(type, payload);
+        const device = this.client.getConnectedDevice();
+        const mtu = device?.mtu || 23;
+        // MTU - 3 bytes (ATT overhead) - Protocol Header - Protocol Footer
+        const maxPayloadSize = mtu - 3 - FRAME_CONSTANTS.HEADER_SIZE - FRAME_CONSTANTS.FOOTER_SIZE;
+        // Ensure reasonable bounds (at least 1 byte, max constrained by protocol constant)
+        const safeMaxDataSize = Math.max(1, Math.min(maxPayloadSize, FRAME_CONSTANTS.MAX_DATA_SIZE));
+
+        console.debug(`[BleProtocolService] Sending with MTU=${mtu}, maxDataSize=${safeMaxDataSize}`);
+
+        const frames = ProtocolManager.createFrame(type, payload, FRAME_CONSTANTS.HEAD_APP_TO_DEVICE, true, safeMaxDataSize);
         const total = frames.length;
         console.debug(`Sending ${total} frames`);
         for (let i = 0; i < total; i++) {
@@ -160,6 +169,7 @@ export class BleProtocolService {
             if (onProgress) {
                 onProgress((i + 1) / total);
             }
+
             console.debug("Wrote frame", result);
         }
     }
diff --git a/ble/services/FileTransferService.ts b/ble/services/FileTransferService.ts
index 9790112..c0568c0 100644
--- a/ble/services/FileTransferService.ts
+++ b/ble/services/FileTransferService.ts
@@ -1,12 +1,13 @@
-import { BleProtocolService } from './BleProtocolService';
-import { COMMAND_TYPES } from '../protocol/Constants';
+import {BleProtocolService} from './BleProtocolService';
+import {COMMAND_TYPES} from '../protocol/Constants';
 
 
 export class FileTransferService {
     private static instance: FileTransferService;
     private protocol = BleProtocolService.getInstance();
-    
-    private constructor() {}
+
+    private constructor() {
+    }
 
     public static getInstance(): FileTransferService {
         if (!FileTransferService.instance) {
@@ -22,21 +23,27 @@ export class FileTransferService {
                 throw new Error(`Failed to load file: ${response.statusText}`);
             }
             const blob = await response.blob();
-            
+
             const reader = new FileReader();
             const arrayBuffer = await new Promise<ArrayBuffer>((resolve, reject) => {
                 reader.onload = () => resolve(reader.result as ArrayBuffer);
                 reader.onerror = reject;
                 reader.readAsArrayBuffer(blob);
             });
-            
+
             await this.protocol.send(deviceId, type, arrayBuffer, onProgress);
         } catch (e) {
             console.error("File transfer failed", e);
             throw e;
         }
     }
-    
+
+    public async transferTestPackage(deviceId: string, onProgress?: (progress: number) => void) {
+        const arrayBuffer = new Uint8Array(512);
+        console.debug(`test package size = ${arrayBuffer.byteLength}`)
+        await this.protocol.send(deviceId, COMMAND_TYPES.TRANSFER_ANI_VIDEO, arrayBuffer, onProgress);
+    }
+
     public async transferOta(deviceId: string, filePath: string) {
         return this.transferFile(deviceId, filePath, COMMAND_TYPES.OTA_PACKAGE);
     }