对 Android 中的 BLE 定向广告 (ADV_DIRECT_IND) 做出反应

Question

如何对Android中的定向广告 (ADV_DIRECT_IND == 0001)做出反应？

有一个 BLE 小工具可以将定向广告发送到 Android phone（目前使用 phone 的硬编码 MAC 地址）并且在我的 Android app 我想做出反应并启动与小工具的连接并从小工具读取 org.bluetooth.characteristic.location_and_speed 值：

请告知是否可以通过Android 5 API。

Answer 1

直接广告 确实有效 - 至少在 HTC M8 phone 和 Android 5.0 (API 21 级及以上）。

解决方案是将设备地址添加到 ScanFilter。

如果将过滤器留空，将不会调用扫描回调。

这是我的工作代码：

public static final String TAG = "My_BLE_app";

public static final String DEVICE_1 = "D4:BE:84:72:5B:8E";
public static final String DEVICE_2 = "C4:39:07:19:60:E2";

private Context mContext;
private BluetoothAdapter mBluetoothAdapter;
private BluetoothLeScanner mScanner;
private ScanSettings mSettings;
private List<ScanFilter> mFilters = new ArrayList<ScanFilter>();

首先是初始化BLE的方法：

public boolean init() {
    BluetoothManager bluetoothManager = (BluetoothManager) mContext.getSystemService(Context.BLUETOOTH_SERVICE);
    mBluetoothAdapter = bluetoothManager.getAdapter();
    if (mBluetoothAdapter == null)
        return false;

    mScanner = mBluetoothAdapter.getBluetoothLeScanner();
    mSettings = new ScanSettings.Builder().setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY).build();

    mFilters.add(new ScanFilter.Builder().setDeviceAddress(DEVICE_1).build());
    mFilters.add(new ScanFilter.Builder().setDeviceAddress(DEVICE_2).build());

    return mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE);
}

然后是扫描回调：

private ScanCallback mDirectedScanCallback = new ScanCallback() {
    @Override
    public void onScanResult(int callbackType, ScanResult result) {
        processResult(result);
    }

    @Override
    public void onBatchScanResults(List<ScanResult> results) {
        for (ScanResult result: results) {
            processResult(result);
        }
    }

    private void processResult(ScanResult result) {
        BluetoothDevice device = result.getDevice();
        if (device == null)
            return;

        String address = device.getAddress();
        if (!BluetoothAdapter.checkBluetoothAddress(address))
            return;

        int rssi = result.getRssi();

        Log.d(TAG, "address=" + address + ", rssi=" + rssi);

        // TODO connect to the device in under 1 second
    }
};

最后是开始扫描的代码：

mScanner.startScan(mFilters, mSettings, mDirectedScanCallback);

一个问题仍然悬而未决：

我不知道如何在Android端检测扫描类型——也就是说扫描是否是定向的。

Answer 2

部分回答开放式问题：
我注意到 ScanRecord.getBytes() 是空的——全是“\0”——用于定向扫描 (ADV_DIRECT_IND)——但否则会包含广告数据 (ADV_IND)。

对 Android 中的 BLE 定向广告 (ADV_DIRECT_IND) 做出反应

Reacting to BLE directed advertising (ADV_DIRECT_IND) in Android

android

bluetooth

bluetooth-lowenergy

android-bluetooth

android-ble