蓝牙

EC-A1684JD4 FD 支持无线蓝牙,可以通过 hciconfig -a 命令显示蓝牙设备信息:

linaro@bm1684:~$ hciconfig -a
hci0:	Type: Primary  Bus: USB
	BD Address: 20:57:9E:BA:7C:EC  ACL MTU: 1021:8  SCO MTU: 255:16
	UP RUNNING 
	RX bytes:650 acl:0 sco:0 events:41 errors:0
	TX bytes:2170 acl:0 sco:0 commands:41 errors:0
	Features: 0xff 0xff 0xff 0xfa 0xdb 0xbd 0x7b 0x87
	Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
	Link policy: RSWITCH HOLD SNIFF PARK 
	Link mode: SLAVE ACCEPT 
	Name: 'bm1684'
	Class: 0x000000
	Service Classes: Unspecified
	Device Class: Miscellaneous, 
	HCI Version: 4.2 (0x8)  Revision: 0xaba8
	LMP Version: 4.2 (0x8)  Subversion: 0xa0cd
	Manufacturer: Realtek Semiconductor Corporation (93)

注意的是,如果打印如下错误信息:

Can't open HCI socket.: Address family not supported by protocol

则可能是可加载模块的依赖性出现问题,此时重新加载依赖性,并软重启即可:

sudo -i
depmod -a
reboot

查看当前是主设备还是从设备:

linaro@bm1684:~$ hciconfig hci0 lm
hci0:	Type: Primary  Bus: USB
	BD Address: 20:57:9E:BA:7C:EC  ACL MTU: 1021:8  SCO MTU: 255:16
	Link mode: SLAVE ACCEPT # 从设备

启动 PulseAudio 服务作为用于媒体设备:

linaro@bm1684:~$ pulseaudio --start --log-target=syslog

连接蓝牙设备步骤如下:

(1)启动蓝牙管理工具:

linaro@bm1684:~$ bluetoothctl
[NEW] Controller 20:57:9E:BA:7C:EC bm1684 [default]

(2)上电蓝牙控制器:

[bluetooth]# power on
Changing power on succeeded

(3)将蓝牙代理设置为默认值:

[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful

(4)打开可被其他蓝牙设备发现:

[bluetooth]# discoverable on
Changing discoverable on succeeded
[CHG] Controller 20:57:9E:BA:7C:EC Discoverable: yes

(5)此时在智能手机就能发现 EC-A1684JD4 FD 蓝牙设备,手机点击后就能配对上去:

[NEW] Device A4:90:CE:DF:64:4F iQOO Neo6 SE
[CHG] Device A4:90:CE:DF:64:4F Modalias: bluetooth:v001Dp1200d1436
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001105-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 0000110a-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001112-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001115-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001116-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 0000111f-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 0000112d-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 0000112f-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001132-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001800-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 00001801-0000-1000-8000-00805f9b34fb
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 2c042b0a-7f57-4c0a-afcf-1762af70257c
[CHG] Device A4:90:CE:DF:64:4F UUIDs: 8fa9c715-bd1f-596c-a1b0-13162b15c892
[CHG] Device A4:90:CE:DF:64:4F ServicesResolved: yes
[CHG] Device A4:90:CE:DF:64:4F Paired: yes
[CHG] Device A4:90:CE:DF:64:4F ServicesResolved: no
[CHG] Device A4:90:CE:DF:64:4F Connected: no
[CHG] Controller 20:57:9E:BA:7C:EC Discoverable: no

(6)连接手机设备:

[bluetooth]# connect A4:90:CE:DF:64:4F
Attempting to connect to A4:90:CE:DF:64:4F
[CHG] Device A4:90:CE:DF:64:4F Connected: yes
Connection successful
[CHG] Device A4:90:CE:DF:64:4F ServicesResolved: yes
[iQOO Neo6 SE]# 

(7)把手机设备设置成信任:

[iQOO Neo6 SE]# trust A4:90:CE:DF:64:4F
[CHG] Device A4:90:CE:DF:64:4F Trusted: yes
Changing A4:90:CE:DF:64:4F trust succeeded

蓝牙音频

蓝牙音频可以使用 bluez-alsa 工具,这是一个蓝牙音频 ALSA 后端实用程序。

安装 bluez-alsa 工具

EC-A1684JD4 FD 默认没有安装该工具,用户需要自行编译安装,这里演示 1.3.0 版本的步骤,如下:

(1)下载源码包:https://github.com/Arkq/bluez-alsa/releases/tag/v1.3.0

(2)安装依赖:

sudo apt install -y libasound2-dev libbluetooth-dev libglib2.0-dev libsbc-dev libfdk-aac-dev pkgconf

(3)解压:

tar xzvf bluez-alsa-1.3.0.tar.gz
cd bluez-alsa-1.3.0

(4)编译与安装:

autoreconf --install
mkdir build && cd build
../configure --enable-aac --enable-debug
make && make install

音频测试

安装完成后可以连接蓝牙耳机或者音箱进行音乐播放,首先将蓝牙配置成主设备模式:

sudo hciconfig hci0 lm master

开启 bluez-alsa 服务,注意 PulseAudio 服务与 bluez-alsa 是互斥的:

# 去掉 PulseAudio 进程
killall pulseaudio
# 开启 bluez-alsa 服务用于连接蓝牙耳机或音响
bluealsa -p a2dp-source -p hsp-ag &

连接蓝牙耳机:

[bluetooth]# connect 0C:AE:BD:9B:BB:5C
Attempting to connect to 0C:AE:BD:9B:BB:5C
[CHG] Device 0C:AE:BD:9B:BB:5C Connected: yes
Connection successful
[CHG] Device 0C:AE:BD:9B:BB:5C ServicesResolved: yes
[EDIFIER LolliPods 2022版]# 

另外开启一个登录,执行以下命令播放音频:

aplay -D bluealsa:HCI=hci0,DEV=0C:AE:BD:9B:BB:5C,PROFILE=a2dp example.wav

关于 bluez-alsa 更多使用可参考源代码仓库:https://github.com/Arkq/bluez-alsa/tree/v1.3.0

文件收发

蓝牙文件收发可以使用 OBEX 协议,它以对象模型封装信息数据,以会话协议规范传输应用。

在 Linux 中需要用到 Obex 服务,首先 EC-A1684JD4 FD 根据前面的步骤连接好蓝牙设备,然后开启 Obex 守护进程,并设置接收的目录为 /home/linaro/

/usr/lib/bluetooth/obexd -r /home/linaro -a -d &

使用 obex push 服务

首先将蓝牙配置成主设备模式:

sudo hciconfig hci0 lm master

查找手机 Obex Push 服务的通道:

linaro@bm1684:~$ sdptool search --bdaddr A4:90:CE:DF:64:4F OPUSH
Searching for OPUSH on A4:90:CE:DF:64:4F ...
Service Name: OBEX Object Push
Service RecHandle: 0x1000d
Service Class ID List:
  "OBEX Object Push" (0x1105)
Protocol Descriptor List:
  "L2CAP" (0x0100)
  "RFCOMM" (0x0003)
    Channel: 12
  "OBEX" (0x0008)
Profile Descriptor List:
  "OBEX Object Push" (0x1105)
    Version: 0x0102

Searching for OPUSH on A4:90:CE:DF:64:4F ...
Service Search failed: Invalid argument

可以看到通道为 12,紧接着就能把文件 push 到手机上:

linaro@bm1684:~$ obexftp --nopath --noconn --uuid none --bluetooth A4:90:CE:DF:64:4F --channel 12 --put sn.txt
Suppressing FBS.
Connecting..\done
Sending "sn.txt".../done
Disconnecting..-done

此时手机端就可看到是否接收文件的弹窗。

使用 obexctl 交互命令行

以下演示 EC-A1684JD4 FD 收文件的步骤:

(1)设备端(从设备)开启 obex 服务:

root@firefly:~# systemctl --user start obex

(2)进入交互命令行:

root@firefly:~# obexctl 
[NEW] Client /org/bluez/obex 

(3)连接 EC-A1684JD4 FD (主设备):

[obex]# connect 20:57:9E:BA:7C:EC
Attempting to connect to 20:57:9E:BA:7C:EC
...
[NEW] Session /org/bluez/obex/client/session2 [default]
[NEW] ObjectPush /org/bluez/obex/client/session2 

(4)发送文件:

[20:57:9E:BA:7C:EC]# send /root/test.txt
Attempting to send /root/test.txt to /org/bluez/obex/client/session1
[NEW] Transfer /org/bluez/obex/client/session1/transfer1
Transfer /org/bluez/obex/client/session1/transfer1
        Status: queued
        Name: test.txt
        Size: 0
        Filename: /root/test.txt
        Session: /org/bluez/obex/client/session1
[CHG] Transfer /org/bluez/obex/client/session1/transfer1 Status: complete

(5)查看 EC-A1684JD4 FD 的 /home/linaro/目录有 test.txt 文件:

linaro@bm1684:~$ ls -l test.txt
-rw------- 1 linaro linaro 0 Nov 25 15:49 test.txt