device disconects when trying to update the firmware

Question

i'm trying to update the firmware version of my Movesense sensors in my Flutter App, after investigating i found out that the steps to do that is put the device into update mode using the mds package, then start the device firmware update using the nordic package. here's what i'm doing:

  @override
  Future<void> startDeviceFirmwareUpdate(String deviceId, String serial, int value) async {
final Map<String, int> contract = {};
contract["NewState"] = value;
await MdsAsync.put(Mds.createRequestUri(serial, "/System/Mode"), jsonEncode(contract));

  NordicDfu().startDfu(
    deviceId,
    'assets/dfu.zip',
    fileInAsset: true,
    onDeviceDisconnecting: (string) {
      print('deviceAddress: $string');
    },
    onDeviceConnected: (address) {
      print("device is connected");
    },
    onDeviceConnecting: (address) {
      print("Device is connecting");
    },
    forceDfu: true,
    onError: (address, error, errorType, message) {
      print(" error  $error, errorType: $errorType, message: $message");
    },
    onProgressChanged: (
      deviceAddress,
      percent,
      speed,
      avgSpeed,
      currentPart,
      partsTotal,
    ) {
      print('deviceAddress: $deviceAddress, percent: $percent');
    },
  );

}

  void connectMovesenseBleDeviceById({
required BleDevice device,
required VoidCallback onConnect,
required VoidCallback onDisconnect,
 }) 
 bleDataSource.connectMovesenseDeviceById(
      device.id,
      onConnnect: (serial) async {
        final metaData = await bleDataSource.getMovesenseSensorInfo(device.serial);
        final deviceAppData = await bleDataSource.getMovesenseSensorAppInfo(device.serial);
        device.metaData = metaData;
        device.appData = deviceAppData;
        // HERE'S where I'm calling it ===>
        bleDataSource.startDeviceFirmwareUpdate(device.id, device.serial, 12);
        if (device.metaData!.isCompatible && device.appData!.isCompatible) {
          onConnect();
          bleDeviceLocalDataSource.persistBleDevice(bleDeviceModel: device as BleDeviceModel);
        }
        if (!_connectedDevicesStreamController.isClosed)
          _connectedDevicesStreamController
              .add(device.copyWith(status: BleDeviceConnectionStatus.connected) as BleDeviceModel);
      },
      onDisconnect: () {
        onDisconnect();
        if (!_connectedDevicesStreamController.isClosed)
          _connectedDevicesStreamController
              .add(device.copyWith(status: BleDeviceConnectionStatus.disconnected) as BleDeviceModel);
      },
      onError: () {
        //TODO: add translations and exception
        throw BluetoothException('Error occured when pairing the device');
      },
    );
  }

my problem here is that after putting the device into update mode, it disconnects from the phone, meaning i cant update it successfully. how can I achieve that?

Answer 1

The DFU mode has a different BLE MAC address than the application mode. In Android you can connect directly to the DFU mode using the MAC address that you find from the "GET /Info".

In iOS devices one cannot connect directly using MAC address (it's hidden by the OS). There you have to scan for the device in the DFU mode which can be found with name "DfuTarg".

Full disclosure: I work for the Movesense team