使用NFC标签启动Android智能手机和Raspberry Pi之间的BLE连接

Question

基本上，我正在开发一款Android应用，只要用户点击手机上的NFC标签，就需要与Raspberry Pi建立BLE连接。该应用程序的目的是当用户通过应用程序本身或通过NFC标签访问视频时，通过Raspberry Pi在电视上播放视频。我计划在其中一个NFC标签中存储RPi的MAC地址，当点击时，应用程序会将该地址传递到应用程序中的蓝牙服务以启动连接。请注意，我必须能够使用此方法启动BLE连接。可能吗？

目前，这是我得到的

蓝牙服务类

public int onStartCommand (Intent intent, int flags, int startId){
    tag = intent.getStringExtra("condition");
    if(tag != null && tag.equals("start")){
        //start ble connection
        tag2 = intent.getStringExtra("macaddress");
        String ADDRESS = tag2;
        bluetoothManager = (BluetoothManager)getSystemService(Context.BLUETOOTH_SERVICE);
        mBluetoothAdapter = bluetoothManager.getAdapter();
        device = mBluetoothAdapter.getRemoteDevice(ADDRESS);
        Log.d("Capstone", device.getAddress());

        bluetoothGatt = device.connectGatt(bluetooth.this, true, new BluetoothGattCallback() {
            @Override
            public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                super.onConnectionStateChange(gatt, status, newState);
                Log.d("Capstone", "BLE connected");
                if (newState == BluetoothProfile.STATE_CONNECTED) {
                    gatt.discoverServices();
                    sendstatus("1");
                }
            }
            @Override
            public void onServicesDiscovered(BluetoothGatt gatt, int status) {
                super.onServicesDiscovered(gatt, status);
                Log.d("Capstone", "Services discovered");
                charCapstone = gatt.getService(UUID.fromString(CAPSTONE_SERVICE_UUID))
                        .getCharacteristic(UUID.fromString(CAPSTONE_CHARACTERISTICS_UUID));
                bluetoothGatt = gatt;

            }});
    }
    else if(tag != null && tag.equals("started")){
        tag3 = intent.getStringExtra("command");
        Log.d("Capstone", tag3);
        if(!tag3.equals("0")){
        charCapstone.setValue(new byte[]{(byte)Integer.parseInt(tag3)});
        bluetoothGatt.writeCharacteristic(charCapstone);
        }
    }
    return START_NOT_STICKY;
}

我如何阅读NFC

private void handleIntent(Intent intent) {
        Parcelable[] messages = intent.getParcelableArrayExtra(
                NfcAdapter.EXTRA_NDEF_MESSAGES);
        for(int i = 0;i < messages.length;i++) {
            NdefMessage message = (NdefMessage) messages[i];
            NdefRecord[] records = message.getRecords();
            NdefRecord record = records[0];
            if(new String(record.getType()).equals("T")) {
                byte[] original = record.getPayload();
                byte[] value = Arrays.copyOfRange(original, 3, original.length);
                String payload = new String(value);
                if(payload.equals(ble)){
                    NdefRecord record2 = records[1];
                    if(new String(record2.getType()).equals("T")) {
                        byte[] original2 = record2.getPayload();
                        byte[] value2 = Arrays.copyOfRange(original2, 3, original2.length);
                        String payload2 = new String(value2);
                        startBluetooth(payload2);
                    }
                }
                else if(a.equals(def)){
                    activityfilter(payload);}
                else {
                    bluetooth(payload);
                }
            }
        }
    }

我使用的两种蓝牙方法将NFC数据传递给蓝牙服务类。

public void startBluetooth(String c){
        Intent serviceIntent = new Intent(this, bluetooth.class);
        serviceIntent.putExtra("condition", "start");
        serviceIntent.putExtra("macaddress", c);
        this.startService(serviceIntent);

 public void bluetooth(String b)
    {
        String s1="1";
        String s2="2";

        Intent serviceIntent1 = new Intent(this, bluetooth.class);
        serviceIntent1.putExtra("condition", "started");
        serviceIntent1.putExtra("command", b);
        Log.d("Capstone", "bluetooth: " + b);
        this.startService(serviceIntent1);

        if(b.equals(s1)){
            Intent videocontrol1 = new Intent(ModeChoose.this, videocontroller.class);
            startActivity(videocontrol1);}

        if(b.equals(s2)){
            Intent videocontrol2 = new Intent(ModeChoose.this, videocontroller.class);
            startActivity(videocontrol2);}
    }



    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            a = intent.getStringExtra("status");
            String b="1";
            if(a.equals(b))
            {
                Toast.makeText(ModeChoose.this,
                        "Bluetooth1 Connected", Toast.LENGTH_LONG).show();
            }

        }
    };

我能够阅读NFC标签。但是我似乎无法与Raspberry Pi建立BLE连接。我是Android的新手。任何帮助将不胜感激。