Question

我希望对广播的设备进行实时响应。自Android Lollipop（SDK 21）以来，有新API，我在

上进行了测试

https://developer.android.com/reference/android/bluetooth/le/ScanSettings.html   ScanSettings.SCAN_MODE_LOW_LATENCY


使用最高占空比扫描。建议仅在应用程序在前台运行时才使用此模式。

这是代码开始扫描

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    List<ScanFilter> filters = new ArrayList<ScanFilter>();
    ScanSettings scanSettings = new ScanSettings.Builder().setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY).build();
    bluetoothLeScanner.startScan(filters, scanSettings, scanCallback );
}

它只是测量ScanCallback（）

中的帧速率

private MeasureFps measureFps = new MeasureFps(6);
private final ScanCallback scanCallback = new ScanCallback() {
    @Override
    public void onScanResult(int callbackType, ScanResult result) {
        measureFps.AddRecord(true);
    }
};

MeasureFps的源代码是here。

我在Nexus 5X上运行测试，这是Android Marshmallow。结果大多超过300毫秒，可能是2秒这些是预期的吗？
如果它们稳定在300毫秒以下就会很棒。

22:18:34.203  I/MeasureFps: Average frame time = 2237.4 ms
22:18:36.792  I/MeasureFps: Average frame time = 485.6 ms
22:18:40.481  I/MeasureFps: Average frame time = 724.0 ms
22:18:43.467  I/MeasureFps: Average frame time = 343.8 ms
22:18:44.904  I/MeasureFps: Average frame time = 251.8 ms
22:18:47.238  I/MeasureFps: Average frame time = 427.8 ms
22:18:48.491  I/MeasureFps: Average frame time = 73.4 ms
22:18:56.139  I/MeasureFps: Average frame time = 288.6 ms
22:18:57.411  I/MeasureFps: Average frame time = 237.4 ms
22:18:58.393  I/MeasureFps: Average frame time = 182.2 ms
22:18:59.953  I/MeasureFps: Average frame time = 310.4 ms
22:19:02.446  I/MeasureFps: Average frame time = 497.2 ms
22:19:04.349  I/MeasureFps: Average frame time = 342.8 ms
22:19:12.984  I/MeasureFps: Average frame time = 1715.0 ms

使用Android BLE ScanSettings.SCAN_MODE_LOW_LATENCY时，ScanCallback的合理频率是多少？

0 个答案: