蓝牙：Basic Audio Profile：Broadcast Assistant Shell

本文档介绍如何运行 BAP Broadcast Assistant 功能。请注意，在下面的示例中，已删除部分调试信息行，以便缩短篇幅并提供更清晰的概览。

Broadcast Assistant 负责为资源受限设备卸载扫描任务，从而避免扫描耗尽电池电量。Broadcast Assistant 应支持对周期性广播进行扫描，并可选择支持周期性广播同步传输（PAST）协议。

Broadcast Assistant 通常是手机或笔记本电脑。Broadcast Assistant 会扫描周期性广播并将信息传输到服务器。

要以交互方式使用 Broadcast Assistant，必须启用 CONFIG_BT_BAP_BROADCAST_ASSISTANT_LOG_LEVEL_DBG。

蓝牙协议栈初始化（ bt init ）并连接设备后，Broadcast Assistant 可以调用 bap_broadcast_assistant discover 发现已连接设备上的 BASS；该命令会开始发现 BASS UUID 并存储句柄，同时订阅所有通知。

uart:~$ bap_broadcast_assistant --help
bap_broadcast_assistant - Bluetooth BAP broadcast assistant client shell
                        commands
Subcommands:
discover          : Discover BASS on the server
scan_start        : Start scanning for broadcasters
scan_stop         : Stop scanning for BISs
add_src           : Add a source <address: P:XX:XX:XX:XX:XX:XX or
                     R:XX:XX:XX:XX:XX:XX> <adv_sid> <sync_pa> <broadcast_id>
                     [<sync_bis>] [<pa_interval>] [<metadata>]
add_broadcast_id  : Add a source by broadcast ID <broadcast_id> <sync_pa>
                     [<sync_bis>] [<metadata>]
add_broadcast_name: Add a source by broadcast name <broadcast_name> <sync_pa>
                     [<sync_bis>] [<metadata>]
add_pa_sync       : Add a PA sync as a source <sync_pa> <broadcast_id>
                     [bis_index [bis_index [bix_index [...]]]]>
mod_src           : Set sync <src_id> <sync_pa> [<pa_interval> | "unknown"] [<sync_bis>]
                     [<metadata>]
broadcast_code    : Send a string-based broadcast code of up to 16 bytes
                     <src_id> <broadcast code>
rem_src           : Remove a source <src_id>
read_state        : Remove a source <index>

用法示例

设置

uart:~$ bt init
uart:~$ bap init
uart:~$ bt connect P:xx:xx:xx:xx:xx:xx

连接后

开始扫描服务器的周期性广播：

备注

Broadcast Assistant 实际上不会开始扫描周期性广播，因为在撰写本文时该功能尚未实现。

uart:~$ bap_broadcast_assistant discover
BASS discover done with 1 recv states
uart:~$ bap_broadcast_assistant scan_start true
BASS scan start successful
Found broadcaster with ID 0x05BD38 and addr R:1E:4D:0A:AA:6E:49 and sid 0x00

使用 add_src 添加源端到接收状态：

uart:~$ bap_broadcast_assistant add_src P:11:22:33:44:55:66 5 1 1
BASS recv state: src_id 0, addr P:11:22:33:44:55:66, sid 5, sync_state 1, encrypt_state 000000000000000000000000000000000
     [0]: BIS sync 0, metadata_len 0

使用 add_broadcast_id 添加源端到接收状态（推荐）：

uart:~$ bap_broadcast_assistant add_broadcast_id 0x05BD38 true
[DEVICE]: R:1E:4D:0A:AA:6E:49, AD evt type 5, RSSI -28 Broadcast Audio Source C:0 S:0 D:0 SR:0 E:1 Prim: LE 1M, Secn: LE 2M, Interval: 0x03c0 (1200000 us), SID: 0x0
Found BAP broadcast source with address R:1E:4D:0A:AA:6E:49 and ID 0x05BD38
BASS recv state: src_id 0, addr R:1E:4D:0A:AA:6E:49, sid 0, sync_state 0, encrypt_state 0
      [0]: BIS sync 0x0000, metadata_len 0
BASS add source successful
BASS recv state: src_id 0, addr R:1E:4D:0A:AA:6E:49, sid 0, sync_state 2, encrypt_state 0
      [0]: BIS sync 0x0000, metadata_len 0
BASS recv state: src_id 0, addr R:1E:4D:0A:AA:6E:49, sid 0, sync_state 2, encrypt_state 0
      [0]: BIS sync 0x0000, metadata_len 4
               Metadata length 2, type 2, data: 0100

修改接收状态：

uart:~$ bap_broadcast_assistant mod_src 0 true 0x03c0 0x02
BASS modify source successful
BASS recv state: src_id 0, addr R:1E:4D:0A:AA:6E:49, sid 0, sync_state 2, encrypt_state 0
      [0]: BIS sync 0x0001, metadata_len 4
               Metadata length 2, type 2, data: 0100

提供广播代码：

uart:~$ bap_broadcast_assistant broadcast_code 0 secretCode
Sending broadcast code:
00000000: 73 65 63 72 65 74 43 6f 64 65 00 00 00 00 00 00 |secretCo de....|
uart:~$ BASS broadcast code successful