android - Alt Beacon Android 不稳定

Question

我正在构建一个基于 Alt Beacon 的 Android 应用程序。我应该以这样的事实作为序言:我的测试设备是运行 Android 4.4 的 Digiland (P-O-S) 平板电脑。

我正在使用 Radius Networks USB 信标及其 Alt Beacon 库:https://github.com/AltBeacon/android-beacon-library

在我自己的应用程序和库提供的引用应用程序中，我发现信标明显不稳定/检测时间极慢。例如，您可以在下面看到引用应用程序的日志。平板电脑始终与信标保持不超过 1/2 米的距离。

以前有人见过这种行为吗？难道我做错了什么？信标上的广播速率似乎设置为 10Hz，功率似乎设置为最大。我应该买一个不同的设备并尝试一下吗？我看到其他一些帖子建议我关闭 wifi，这个日志是在 wifi 关闭的情况下进行的试验。

我应该注意的一件事是，我在应用程序子类中使用以下代码块增加了扫描频率:

beaconManager.setBackgroundBetweenScanPeriod(9000l);
beaconManager.setBackgroundScanPeriod(1000l);
beaconManager.setForegroundBetweenScanPeriod(9000l);
beaconManager.setForegroundScanPeriod(1000l);
try{
    beaconManager.updateScanPeriods();
}catch (RemoteException e){
    e.printStackTrace();
}

我不确定这是否做得不当，但是当我删除它时，我仍然看到下面日志中描述的相同行为，只是持续了更长的一段时间。

人们提出的任何建议都将不胜感激，因为我觉得我正在为此而努力!

07-01 15:23:59.005  10771-10771/org.altbeacon.beaconreference D/ReferenceApplication﹕ setting up background monitoring for beacons and power saving
07-01 15:23:59.655  10771-10816/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:23:59.655  10771-10816/org.altbeacon.beaconreference D/ReferenceApplication﹕ auto launching MainActivity
07-01 15:24:20.154  10771-11297/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:24:39.174  10771-11486/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:25:00.132  10771-11647/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:25:09.472  10771-11730/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:25:30.123  10771-11871/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:25:39.173  10771-11954/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:26:00.065  10771-12070/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:26:29.099  10771-12083/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:26:29.100  10771-12083/org.altbeacon.beaconreference D/ReferenceApplication﹕ Sending notification.
07-01 15:26:40.112  10771-12096/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:27:19.120  10771-12127/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:27:19.120  10771-12127/org.altbeacon.beaconreference D/ReferenceApplication﹕ Sending notification.
07-01 15:27:40.041  10771-12208/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:27:59.110  10771-12786/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:28:30.144  10771-13052/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:28:39.202  10771-13131/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:28:50.133  10771-13226/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:29:09.125  10771-13375/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:29:30.119  10771-13452/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:29:49.144  10771-13473/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:30:00.060  10771-13510/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:30:19.134  10771-13552/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:30:19.135  10771-13552/org.altbeacon.beaconreference D/ReferenceApplication﹕ Sending notification.
07-01 15:30:30.096  10771-13560/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:31:09.124  10771-13575/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:31:09.125  10771-13575/org.altbeacon.beaconreference D/ReferenceApplication﹕ Sending notification.
07-01 15:31:20.110  10771-13576/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:31:29.101  10771-13578/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.
07-01 15:31:29.101  10771-13578/org.altbeacon.beaconreference D/ReferenceApplication﹕ Sending notification.
07-01 15:32:40.101  10771-13647/org.altbeacon.beaconreference D/ReferenceApplication﹕ did exit region
07-01 15:32:59.131  10771-13651/org.altbeacon.beaconreference D/ReferenceApplication﹕ did enter region.

需要注意的一件更有趣的事情是，当我在日志中对 onScanResult 进行过滤时，我会看到以下内容:

07-01 15:45:49.074  10771-10839/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=24:4B:03:2E:00:D9 RSSI=-91
07-01 15:45:49.117    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=00:07:80:1E:7E:B7, rssi=-56
07-01 15:45:49.120  10771-10784/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=00:07:80:1E:7E:B7 RSSI=-56
07-01 15:45:49.365    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=62:44:C6:64:4D:A5, rssi=-76
07-01 15:45:49.368  10771-10783/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=62:44:C6:64:4D:A5 RSSI=-76
07-01 15:45:59.082    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=62:44:C6:64:4D:A5, rssi=-77
07-01 15:45:59.084  10771-10784/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=62:44:C6:64:4D:A5 RSSI=-77
07-01 15:45:59.130    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=00:07:80:1E:7E:B7, rssi=-59
07-01 15:45:59.133  10771-10783/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=00:07:80:1E:7E:B7 RSSI=-59
07-01 15:45:59.140    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=24:4B:03:2E:00:D9, rssi=-76
07-01 15:45:59.141  10771-10839/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=24:4B:03:2E:00:D9 RSSI=-76
07-01 15:46:09.115    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=00:07:80:1E:7E:B7, rssi=-58
07-01 15:46:09.117  10771-10783/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=00:07:80:1E:7E:B7 RSSI=-58
07-01 15:46:09.124    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=24:4B:03:2E:00:D9, rssi=-86
07-01 15:46:09.126  10771-10839/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=24:4B:03:2E:00:D9 RSSI=-86
07-01 15:46:09.135    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=62:44:C6:64:4D:A5, rssi=-76
07-01 15:46:09.139  10771-10784/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=62:44:C6:64:4D:A5 RSSI=-76
07-01 15:46:19.060    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=24:4B:03:2E:00:D9, rssi=-91
07-01 15:46:19.062  10771-10839/org.altbeacon.beaconreference D/BluetoothAdapter﹕ onScanResult() - Device=24:4B:03:2E:00:D9 RSSI=-91
07-01 15:46:19.092    1425-1495/? D/BtGatt.GattService﹕ onScanResult() - address=00:07:80:1E:7E:B7, rssi=-64

00:07:80 设备是我的信标，但我完全不知道 24:4B:03 设备是什么时候。有谁知道我如何获得有关该设备的更多数据？它有可能干扰我的实际信号吗？我尝试过同时使用

Region region = new Region("backgroundRegion",
                Identifier.parse("2F234454-CF6D-4A0F-ADF2-F4911BA9FFA6"), null, null);

和

Region region = new Region("backgroundRegion",null, null, null); 

不幸的是，我在这两种变化中都遇到了这种随机波动。

更新:

我还在激活 beaconManager.setDebug(true) 标志的情况下运行了此命令。这是resulting log

更新2:

我将信标切换为仅广播 iBeacon，问题似乎在大约 10 分钟后消失了。不幸的是问题很快又回来了。通过查看日志，我现在看到的情况完全不同了。日志可见here 。我的假设是问题出在这一行:

07-01 21:46:31.035    2499-2499/com.avtar.truckkeeper D/CycledLeScanner﹕ cancel wakeup alarm: PendingIntent{41f32070: android.os.BinderProxy@41d8f750}

任何想法/帮助将不胜感激!

Answer 1

根据对答案底部链接的“结果日志”的分析，我怀疑发生了几件事:

1. 发送信标配置为发送 AltBeacon 和 iBeacon 数据包。
2. Android Beacon 库尚未配置为检测 iBeacon 数据包，仅检测默认的 AltBeacon 数据包。
3. 发射信标处于可连接模式。
4. 当信标处于可连接模式时，Digiland (P-O-S) 平板电脑在每个扫描周期只能检测来自每个不同蓝牙 LE 设备的一个数据包。 (其他几个 Android 型号也有这种行为，包括 Nexus 4 和 Moto G)
5. 扫描间隔已配置为超长 - 每 10 秒扫描一秒。

所有这些事情一起创造了一场完美 Storm ，导致了这些问题:

由于 (4) 中描述的缺陷以及信标处于 (3) 中描述的可连接模式这一事实，这意味着每个扫描周期只会拾取一个数据包。因为信标正在发送如 (1) 中所述的交错广告，这意味着该数据包有 50-50 的机会是 iBeacon 数据包。如果是 iBeacon 数据包，由于库尚未配置为检测 iBeacons(如(2)中所述)，因此在该周期中不会进行任何检测。并且由于扫描周期为10秒长(如5中所述)，这将导致间歇性区域退出和重新进入。 (如果 10 秒内没有看到信标，库会触发区域退出。)

更改其中任何一项都可能会使问题消失:

1. 重新配置您的信标以关闭 iBeacon 传输(或配置库以检测 iBeacon 传输。)

2. 缩短信标的连接超时时间——例如60秒后。一旦无法连接，平板电脑将能够在每个扫描周期获取多个数据包，问题就会消失。

3. 减少扫描周期的时间长度。如果您在前台保留默认的 1100 毫秒扫描时间和 0 毫秒的扫描时间间隔，则在 10 秒区域超时触发之前，库将有 9 个周期来检测信标。 9 个周期内未检测到信标的 50-50 几率将变为 0.5^9 = 0.1% 几率。