前面介绍过 ESP32 作为蓝牙音频接收端(蓝牙音箱),这里介绍它作为蓝牙音频的播放端。
首先需要确定蓝牙接收器的名称,用笔记本电脑连接后,可以再设备管理器中看到,这里我使用的是一款蓝牙耳机,名称是“JABRA TALK”:

接下来需要安装 ESP32-A2DP-master 这个库。下面的代码是从这个库的Example 中修改而来,代码如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 | /* Streaming of sound data with Bluetooth to an other Bluetooth device. We provide the complete sound data as a simple c array which can be prepared e.g. in the following way - Open any sound file in Audacity. Make sure that it contains 2 channels - Select Tracks -> Resample and select 44100 - Export -> Export Audio -> Header Raw ; Signed 16 bit PCM - Convert to c file e.g. with "xxd -i file_example_WAV_1MG.raw file_example_WAV_1MG.c" - add the const qualifier to the array definition. E.g const unsigned char file_example_WAV_1MG_raw[] = { Copyright (C) 2020 Phil Schatzmann This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "BluetoothA2DPSource.h" #include "StarWars30.h" BluetoothA2DPSource a2dp_source; //SoundData *data = new TwoChannelSoundData((Channels*)StarWars10_raw,StarWars10_raw_len/4); SoundData * data = new OneChannelSoundData((int16_t * )StarWars30_raw, StarWars30_raw_len / 2 ); void setup () { Serial.begin ( 115200 ); Serial.println ( "Start" ); a2dp_source.start( "JABRA TALK" ); } void loop () { if (a2dp_source.isConnected() = = true ) { Serial.println ( "Connected!" ); if (a2dp_source.hasSoundData() = = true ) { Serial.println ( "Has sound!" ); } else { Serial.println ( "No sound!" ); a2dp_source.writeData(data); } } else { Serial.println ( "Not connected!" ); } delay ( 2000 ); } |
特别注意,因为代码有音频数据需要特别选择 Huge APP 模式:

测试使用的板子是 ESP-WROOM-32,特点是价格偏移兼容性还不错(同样的我试验了 TinkerNode,播放时有卡顿,似乎后台有人一直占用 Soc):


测试的视频:
https://www.bilibili.com/video/BV1wa411A7et/
特别注意:连接时需要比较有耐心多次尝试,先将耳机设置为配对模式,然后ESP32上电。从资料来看,这样的搭配似乎有兼容性问题,淘宝上的卖家都不承诺蓝牙音频端能够兼容客户的蓝牙接收端。
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2023年5月10日