Bluetooth04

蓝牙问题汇总

https://race604.com/android-ble-in-action/

1. 连接断开之后可以根据实际情况进行重连，但如果是连接失败的情况，建议不要立即重连，而是调用void closeBluetoothGatt()清空一下状态，并延迟一段时间等待复位，否则会把gatt阻塞，导致手机不重启蓝牙就再也无法连接任何设备的严重情况。

   https://github.com/Jasonchenlijian/FastBle/blob/master/README_1.2.x.md

2. 每当设备断开连接时，请确保在BluetoothGatt对象上调用close()并将其设置为null,

   解决方法:始终在断开连接时关闭gatt实例，并在每次连接时创建一个新的gatt实例。

   在onLeScan(..)中启动一个新线程，然后进行连接

   https://stackoom.com/question/1Cyqr/Android-%E8%93%9D%E7%89%99%E4%BD%8E%E5%8A%9F%E8%80%97%E4%B8%8D%E7%A8%B3%E5%AE%9A

BluetoothLeScanner: could not find callback wrapper

3. 连接失败处理

   分两个平台来说，iOS端也有连接失败的委托，但是好像几乎不会发生这种情况，至少我从来没遇见过，而对于同款设备，android常常会出现连接失败的情况，status != BluetoothGatt.GATT_SUCCESS ，android端开发请不要把连接失败和断开连接放在一块处理，因为断开连接可以直接尝试重新连接，而连接失败后尝试重新连接，需要加一些延时，并且需要gatt.close，清空一下状态，否则会把gatt阻塞导致手机不重启蓝牙就再也无法连接任何设备的情况。

http://liuyanwei.jumppo.com/2017/01/23/zhihu-live-a-hour-for-bluetooth-0.html

4. 扫描广播包

所有外设，只有在发出广播包的情况下，才能被central发现，绝大多数情况下，外设被连接后就不会发出广播（也有例外），很多人遇到无法找到设备的问题，大多属于这种情况。 重复扫描问题——————

http://liuyanwei.jumppo.com/2017/01/23/zhihu-live-a-hour-for-bluetooth-0.html

5. Android 7+ will stop scanning if it continues without stopping at all for 30 minutes or more. This was added as a feature to prevent battery drain in case developers had inadvertently or abusively left scanning on forever.

   https://github.com/AltBeacon/android-beacon-library/issues/528

https://blog.csdn.net/m0_37796683/article/details/83657204

6. status 133

   https://blog.csdn.net/baidu_26352053/article/details/54571688

7. unregisterApp() - mClientIf=5

8. filter

   https://juejin.im/post/5d37d4d6f265da1bc414958a

9. 防止Android7中的BLE扫描滥用，从而做了一些限制，即不要在30s内对蓝牙扫描
   重复开启-关闭超过5次。

   https://blog.classycode.com/undocumented-android-7-ble-behavior-changes-d1a9bd87d983

• 蓝牙添加扫描间隔

​ https://github.com/haodynasty/AndroidBleManager

​ https://github.com/AltBeacon/android-beacon-library

应用如何做自动重连

其实自动重连比想象的要简单许多，无论是android还是ios端，只需要在设备断开连接的委托方法中，重新调用gatt.connet或者是centralManager.connet方法就可以了，无论当时设备是否有点，是否在周围，当设备再次开会或者连接到可连接范围内，都会自动被连上，就是这么简单。

http://liuyanwei.jumppo.com/2017/01/23/zhihu-live-a-hour-for-bluetooth-0.html

Intent mIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(mIntent, 1);

mBluetoothAdapter.enable();
mBluetoothAdapter.disable();

https://blog.csdn.net/u014418171/article/details/81219297

扫描

过滤

Scanning by device name

Looking for a device by it’s name has 2 main use cases: to look for 1 specific device or to look for 1 specific device model. For example, my Polar H7 chest strap advertises itself as “Polar H7 391BB014”. The latter part (‘391BB014’) is a unique number (or serial number) and the first part is generic for all Polar H7 devices. This is very common practice. Unfortunately the device name scan filter can only be used to find specific devices as it does full string matching. If you want to find all Polar H7 devices you will need to do a ‘substring’ compare on ‘Polar H7’, but you can’t do that with a filter. You just need to pass null as the filter and do the substring comparison yourself in onScanResult.

So here is an example of how to scan for devices by exact name

String[] names = new String[]{"Polar H7 391BB014"};
List<ScanFilter> filters = null;
if(names != null) {
    filters = new ArrayList<>();
    for (String name : names) {
        ScanFilter filter = new ScanFilter.Builder()
                .setDeviceName(name)
                .build();
        filters.add(filter);
    }
}
scanner.startScan(filters, scanSettings, scanCallback);

https://medium.com/@martijn.van.welie/making-android-ble-work-part-1-a736dcd53b02

android蓝牙自动连接

http://www.cocoachina.com/articles/83844

Ble library

Android-BLE-Library

LoggableBleManager public void log(final int priority, @NonNull final String message)
是日志打印出口
是 BleManager public void log(final int priority, @NonNull final String message)的实现

nRF-Logger-API是手机日志查看工具

public abstract class LoggableBleManager<T extends BleManagerCallbacks> extends BleManager<T> {
   private ILogSession logSession;

   /**
    * The manager constructor.
    * <p>
    * After constructing the manager, the callbacks object must be set with
    * {@link #setManagerCallbacks(BleManagerCallbacks)}.
    *
    * @param context the context.
    */
   public LoggableBleManager(@NonNull final Context context) {
      super(context);
   }

   /**
    * Sets the log session to log into.
    *
    * @param session nRF Logger log session to log inti, or null, if nRF Logger is not installed.
    */
   public void setLogger(@Nullable final ILogSession session) {
      logSession = session;
   }

   @Override
   public void log(final int priority, @NonNull final String message) {
      Logger.log(logSession, LogContract.Log.Level.fromPriority(priority), message);
      Log.println(priority, "BleManager", message);
//    Timber.i("BleManager   "+ message);
   }
}