【发布时间】：2019-01-12 23:11:03
【问题描述】：
在执行 apt-get 更新/升级后，使用已知工作 Python 示例的 BLE 扫描在全新的 Raspberry Pi 3 B+（金属罐 CPU）上失败。要重新创建，使用 NOOBS 2.8.2，设置 Pi 并执行 apt-get update 和 upgrade，接受所有建议的更改。然后使用this sample code 扫描BLE 设备。作为诊断的一部分，命令：
hcitool lescan
用于查看是否可以打开 hci0 设备。这导致了错误：
hcitool lescan Set scan parameters failed: Input/output error
此解决方法成功解决了该错误：
hciconfig hci0 down
hciconfig hci0 up
hcitool lescan
但只有在 'hcitool lescan' 开始成功运行之后。目前尚不清楚我们是否必须实际捕获白名单中的扫描设备才能成功（过快而无法捕获和停止）。
示例代码在这些新系统版本上失败：
ii bluez 5.43-2+rpt2+deb9u2 armhf Bluetooth tools and daemons
ii bluez-firmware 1.2-3+rpt6 all Firmware for Bluetooth devices
ii bluez-hcidump 5.43-2+rpt2+deb9u2 armhf Analyses Bluetooth HCI packets
ii libbluetooth-dev 5.43-2+rpt2+deb9u2 armhf Development files for using the BlueZ Linux Bluetooth library
ii libbluetooth3:armhf 5.43-2+rpt2+deb9u2 armhf Library to use the BlueZ Linux Bluetooth stack
ii pi-bluetooth 0.1.8 all Raspberry Pi 3 bluetooth
ii python-bluez 0.22-1 armhf Python wrappers around BlueZ for rapid bluetooth development
但是在这个系统上工作，一次升级回来：
ii bluez 5.43-2+rpt2+deb9u2 armhf Bluetooth tools and daemons
ii bluez-firmware 1.2-3+rpt5 all Firmware for Bluetooth devices
ii libbluetooth-dev 5.43-2+rpt2+deb9u2 armhf Development files for using the BlueZ Linux Bluetooth library
ii libbluetooth3:armhf 5.43-2+rpt2+deb9u2 armhf Library to use the BlueZ Linux Bluetooth stack
ii pi-bluetooth 0.1.7 all Raspberry Pi 3 bluetooth
ii python-bluez 0.22-1 armhf Python wrappers around BlueZ for rapid bluetooth development
编辑：btmon 命令的输出（新的非工作单元）：
Bluetooth monitor ver 5.43
= Note: Linux version 4.14.52-v7+ (armv7l) 0.695265
= Note: Bluetooth subsystem version 2.22 0.695276
= New Index: B8:27:EB:A0:39:EC (Primary,UART,hci0) [hci0] 0.695279
= Open Index: B8:27:EB:A0:39:EC [hci0] 0.695281
= Index Info: B8:27:EB:A0:39:EC (Broadcom Corporation) [hci0] 0.695284
@ RAW Open: python (privileged) version 2.22 {0x0003} [hci0] 0.695289
@ RAW Open: hcitool (privileged) version 2.22 {0x0002} [hci0] 0.695291
@ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.695294
@ MGMT Open: btmon (privileged) version 1.14 {0x0004} 0.695367
> HCI Event: LE Meta Event (0x3e) plen 40 [hci0] 2.692582
LE Advertising Report (0x02)
Num reports: 1
Event type: Scannable undirected - ADV_SCAN_IND (0x02)
Address type: Random (0x01)
Address: 51:46:AD:CA:4C:2F (Resolvable)
Data length: 28
16-bit Service UUIDs (complete): 1 entry
Google (0xfe9f)
Service Data (UUID 0xfe9f): 0000000000000000000000000000000000000000
RSSI: -84 dBm (0xac)
来自较旧的工作单位：
Bluetooth monitor ver 5.43
= Note: Linux version 4.14.34-v7+ (armv7l) 0.396738
= Note: Bluetooth subsystem version 2.22 0.396744
= New Index: B8:27:EB:31:E6:62 (Primary,UART,hci0) [hci0] 0.396746
= Open Index: B8:27:EB:31:E6:62 [hci0] 0.396748
= Index Info: B8:27:EB:31:E6:62 (Broadcom Corporation) [hci0] 0.396749
@ RAW Open: python (privileged) version 2.22 {0x0002} [hci0] 0.396752
@ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.396753
@ MGMT Open: btmon (privileged) version 1.14 {0x0003} 0.396800
> HCI Event: LE Meta Event (0x3e) plen 42 [hci0] 0.534168
LE Advertising Report (0x02)
Num reports: 1
Event type: Non connectable undirected - ADV_NONCONN_IND (0x03)
Address type: Public (0x00)
Address: 0C:F3:EE:B3:B8:53 (EM Microelectronic)
Data length: 30
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
Company: Apple, Inc. (76)
Type: iBeacon (2)
UUID: a6ffa91b-91f4-f2ad-0f4a-6dcf5444232f
Version: 0.256
TX power: -76 dB
RSSI: -70 dBm (0xba)
【问题讨论】：
-
您能否澄清一下“我们是否必须实际捕获白名单中的扫描设备才能使扫描成功（过快而无法捕获和停止）”是什么意思？跨度>
-
请在尝试扫描时发布“sudo btmon”的输出。
-
@davidgyoung 抱歉混淆了这个问题。忘记“过得太快的部分”。现在需要加入白名单吗？
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@emil 添加了包含第一个扫描数据包的 btmon 输出。
标签： python bluetooth-lowenergy raspberry-pi3 ibeacon