Android BLE ScanCallback 低延迟答案

【问题标题】：Android BLE ScanCallback LOW LATENCYAndroid BLE ScanCallback 低延迟
【发布时间】：2017-05-24 16:08:46
【问题描述】：

我正在构建 BLE Android。我的应用程序使用 SCAN_MODE_LOW_POWER 作为设置扫描具有 24/7 后台服务的 BLE 设备（这对我的应用程序至关重要）。当我找到与我的应用程序相关的设备时，我会切换到 SCAN_MODE_LOW_LATENCY，因为此时我的应用程序每 1 秒计数一次。使用 SCAN_MODE_LOW_LATENCY，我会密集接收 ScanCallback，但在某些时候，例如当设备处于睡眠模式时，我会密集接收 10-11 回调，然后暂停 3-4 秒，然后再次回调。

这 3-4 秒的延迟/暂停对我的应用毫无帮助。

即使设备处于睡眠或打盹模式，是否可以进行密集的 ScanCallback？

谢谢。

屏幕开启时登录：

05-25 09:26:27.121 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:27.161 14564-14564/? I/TAG_BLE：BLE onScanResult - isScreenOn :是的

05-25 09:26:27.211 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:27.251 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:27.301 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

...密集的 ScanCallback

05-25 09:26:41.101 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:41.151 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:41.201 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:41.251 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:41.291 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:41.341 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

05-25 09:26:41.391 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :true

屏幕关闭时登录：

05-25 09:26:50.141 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.191 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.221 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.271 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.301 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.351 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.401 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.441 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.501 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.531 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.581 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:50.631 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

--->没有回调5s

05-25 09:26:55.151 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.201 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.251 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.301 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.341 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.381 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.421 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.481 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.521 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.571 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

05-25 09:26:55.611 14564-14564/? I/TAG_BLE: BLE onScanResult - isScreenOn :false

【问题讨论】：

相关developer.android.com/training/monitoring-device-state/…和developer.android.com/training/monitoring-device-state/…
您的应用进程中是否运行了前台服务？如果你还没有，如果你需要在后台进行 BLE 扫描，你应该有一个；否则应用程序可能会在一段时间后终止。
不，我没有前台服务，我正在使用 STICKY 后台服务。问题不存在我的服务没有被杀死（我保证服务不会被杀死）。我总是收到 ScanCallback 回调，但有时没有我想要的那么多。例如，当屏幕解锁时，我收到密集的 ScanCallback 锁定后，我仍在接收回调，但中间有 3-4 秒的暂停。
您运行的是哪个 Android 版本？您能否尝试将其设为前台服务，看看会发生什么？前台服务不受打盹模式的影响。
我在前台服务中得到了相同的结果。我的初始测试是在 Galaxy S6 Android 6.0.1 上进行的，当屏幕解锁时，我有密集的 ScanCallback，但一旦它被锁定，我会有 4-5 秒的暂停在回调之间，当我强制空闲模式时，结果相同。但是对于 Nexus 7.0，即使在空闲模式下，我也总是有密集的回调..我现在很困惑..

标签： android bluetooth-lowenergy

【解决方案1】：

不同的制造商使用不同的蓝牙芯片。因此，这种行为是很有可能的。您是否尝试过每隔一秒左右重新启动一次扫描？只是启动和停止它。

【讨论】：

我试过了，但有时我在重新开始扫描时没有得到回调。结果我也有 3-4 秒没有回调。