NuvotonM487 Audio模块测评

1 开发板介绍

1.1 外设

1.2 特性

1.3 块表

1.4 AUDIO硬件原理

2 开发环境搭建(GCC方式)

PC环境：win10

NuMaker-IoT-M487 上手指南

2.1 Env RT-Thread 开发辅助工具

env_released_1.2.0.7z

解压后即可打开env.bat或env.exe即可使用（注意解压路径里最好不能有中文和空格）

2.2 安装Nu-Linker驱动

Nu-Link_IAR 驱动里有Nu-Link_USB_Driver 1.8.exe这个驱动安装文件。

装完驱动后，使用 USB 线连接开发板的 USB ICE Connector 到 PC 机，会检测到COM口，如下图：

2.3 源码获取

Administrator@BKL85SWJMT1GA7J E:\NuMaker

git clone https://gitee.com/rtthread/rt-thread.git

Cloning into 'rt-thread'...

remote: Enumerating objects: 187653, done.

remote: Counting objects: 100% (13282/13282), done.

remote: Compressing objects: 100% (6418/6418), done.

remote: Total 187653 (delta 8657), reused 9783 (delta 6665), pack-reused 174371

Receiving objects: 100% (187653/187653), 524.46 MiB | 3.55 MiB/s, done.

Resolving deltas: 100% (134067/134067), done.

Updating files: 100% (28432/28432), done.

2.4 下载项目(NuMaker-IoT-M487)相关套件

cd bsp\nuvoton\numaker-iot-m487: 切换到numaker-iot-m487的工作目录；

menuconfig --generate: 根据.config生成rtconfig.h文件；

pkgs --update: 从git repo上更新本地包和Env脚本(应该时根据.config文件)；

menuconfig可以修改整个工程配置；

pkgs —printenv也很有用，可以查看Env的环境变量；

Administrator@BKL85SWJMT1GA7J E:\NuMaker

cd bsp\nuvoton\numaker-iot-m487

​

Administrator@BKL85SWJMT1GA7J E:\NuMaker\rt-thread\bsp\nuvoton\numaker-iot-m487

menuconfig --generate

​

Administrator@BKL85SWJMT1GA7J E:\NuMaker\rt-thread\bsp\nuvoton\numaker-iot-m487

pkgs --update

Cloning into 'E:\NuMaker\rt-thread\bsp\nuvoton\numaker-iot-m487\packages\at_device-latest'...

remote: Enumerating objects: 1647, done.

remote: Counting objects: 100% (150/150), done.

remote: Compressing objects: 100% (138/138), done.

remote: Total 1647 (delta 80), reused 39 (delta 8), pack-reused 1497R

Receiving objects: 100% (1647/1647), 689.47 KiB | 222.00 KiB/s, done.

Resolving deltas: 100% (1050/1050), done.

==============================> AT_DEVICE latest is downloaded successfully.

​

==============================> at_device update done

​

Operation completed successfully.

2.5 GCC 编译项目

Env RT-Thread环境中已有arm-none-eabi交叉编译链；

scons进行自动构建，生成rtthread.bin

2.5.1 检测交叉编译链工具

env_released_1.2.0\env

arm-none-eabi-

arm-none-eabi-addr2line.exe arm-none-eabi-gcc-nm.exe arm-none-eabi-nm.exe

arm-none-eabi-ar.exe arm-none-eabi-gcc-ranlib.exe arm-none-eabi-objcopy.exe

arm-none-eabi-as.exe arm-none-eabi-gcc.exe arm-none-eabi-objdump.exe

arm-none-eabi-c++.exe arm-none-eabi-gcov-tool.exe arm-none-eabi-ranlib.exe

arm-none-eabi-c++filt.exe arm-none-eabi-gcov.exe arm-none-eabi-readelf.exe

arm-none-eabi-cpp.exe arm-none-eabi-gdb-py.exe arm-none-eabi-size.exe

arm-none-eabi-elfedit.exe arm-none-eabi-gdb.exe arm-none-eabi-strings.exe

arm-none-eabi-g++.exe arm-none-eabi-gprof.exe arm-none-eabi-strip.exe

arm-none-eabi-gcc-5.4.1.exe arm-none-eabi-ld.bfd.exe

arm-none-eabi-gcc-ar.exe arm-none-eabi-ld.exe

2.5.2 scons构建

注意：一定要切到项目下构建（rt-thread\bsp\nuvoton\numaker-iot-m487）

scons

scons: Reading SConscript files ...

Newlib version:2.4.0

scons: done reading SConscript files.

scons: Building targets ...

scons: building associated VariantDir targets: build

CC build\applications\main.o

CC build\applications\mnt.o

CC build\board\board_dev.o

CC build\board\NuClockConfig\nutool_modclkcfg.o

CC build\board\NuPinConfig\nutool_pincfg.o

此处打印太多省略

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\AudioCodec\audio_test.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\AudioCodec\acodec_nau88l25.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\BMX055\libraries\BMG160_driver\bmg160.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\BMX055\libraries\BMA2x2_driver\bma2x2.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\BMX055\sensor_bmx055.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\BMX055\libraries\BMM050_driver\bmm050.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\Demo\usbd_cdc_vcom_echo.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\Demo\slcd_show_tick.o

CC E:\NuMaker\rt-thread\bsp\nuvoton\libraries\nu_packages\Demo\usbd_hid_dance_mouse.o

LINK rtthread.elf

arm-none-eabi-objcopy -O binary rtthread.elf rtthread.bin

arm-none-eabi-size rtthread.elf

text data bss dec hex filename

277116 5080 57760 339956 52ff4 rtthread.elf

scons: done building targets.

3 开发板烧录

主要烧录方式两种：

NuMicro MCU 虚拟磁盘；

RT-Thread Studio工具烧录。

这里用的是NuMicro MCU 虚拟磁盘方式，区别是要将NuMaker-IoT-M487 上的 ISW1四个开关都拨到 ‘ON’ 的位置;而RT-Thread Studio工具烧录则是ISW1前三个开关拨到 ‘ON’，第四个开关要拨到 ‘OFF’。

NuMicro MCU 虚拟磁盘的ISW1四个开关状态如下图：

配置完成后，将开发板使用 Micro USB 连接线连接计算机，我的计算机将出现一个 NuMicro MCU 虚拟磁盘。

将上一步编译出的rtthread.bin拷贝到该虚拟磁盘根目录，然后NuMaker M487会自动检测、升级和重启。

• RT - Thread Operating System

  / | \ 4.1.0 build Apr 7 2022 22:24:56

  2006 - 2022 Copyright by RT-Thread team

  This chip does not support TRNG!

  [I/I2C] I2C bus [i2c0] registered

  [I/I2C] I2C bus [i2c1] registered

  [I/I2C] I2C bus [i2c2] registered

  [W/drv.qspi] qspi0 clock max frequency is 48000000Hz (!= 50000000Hz)

  [I/SFUD] Find a Winbond flash chip. Size is 4194304 bytes.

  [I/SFUD] flash0 flash device is initialize success.

  [I/SFUD] Probe SPI flash flash0 by SPI device qspi01 success.

  [I/sal.skt] Socket Abstraction Layer initialize success.

  [I/utest] utest is initialize success.

  [I/utest] total utest testcase num: (0)

  Failed to mount elm on /.

  Try to execute 'mkfs -t elm flash0' first, then reboot.

  [I/at.clnt] AT client(V1.3.1) on device uart1 initialize success.

  [I/sensor] rt_sensor[mag_bmx055] init success

  [I/sensor] rt_sensor[acce_bmx055] init success

  [I/sensor] rt_sensor[gyro_bmx055] init success

  [D/FAL] (fal_flash_init:49) Flash device | OnChip_APROM | addr: 0x00000000 | len: 0x00080000 | blk_size: 0x00001000 |initialized finish.

  [D/FAL] (fal_flash_init:49) Flash device | OnChip_LDROM | addr: 0x00100000 | len: 0x00101000 | blk_size: 0x00001000 |initialized finish.

  [I/FAL] ==================== FAL partition table ====================

  [I/FAL] | name | flash_dev | offset | length |

  [I/FAL] -------------------------------------------------------------

  [I/FAL] | ldrom | OnChip_LDROM | 0x00000000 | 0x00001000 |

  [I/FAL] | aprom | OnChip_APROM | 0x00060000 | 0x00020000 |

  [I/FAL] =============================================================

  [I/FAL] RT-Thread Flash Abstraction Layer initialize success.

  [I/dancemouse] Ready.

  msh />[I/at.dev.esp] esp0 device wifi is disconnect.

  msh />[E/at.clnt] execute command (AT+CWJAP="NT_ZY_BUFFALO","12345678") failed!

  [W/at.dev.esp] esp0 device wifi connect failed, check ssid(NT_ZY_BUFFALO) and password(12345678).

  [I/at.dev.esp] esp0 device network initialize successfully.

  [E/at.clnt] execute command (AT+CWJAP=”NT_ZY_BUFFALO”,”12345678”) failed!表示wifi的ssid和密码不对！

4 AUDIO测试

4.1 wavpayer组件

进入menuconfig界面，选择wavpayer组件

.config - RT-Thread Configuration

→ RT-Thread online packages

→ multimedia packages

→ WavPlayer: Minimal music player for wav file play and record ─

┌──────────────────────────────────────────────────┐

│ --- WavPlayer: Minimal music player for wav file play and record │

│ [ *] Enable support for play (NEW) │

│ (sound0) The play device name (NEW) │

│ [* ] Enable support for record │

│ (sound0) The record device name (NEW) │

│ Version (latest) ---> │

└──────────────────────────────────────────────────┘

├──────────────────────────────────────────────────┤

│ < Exit > < Help > < Save > < Load > │
└──────────────────────────────────────────────────┘
更新组件到本地
pkgs --update
重新编译，生成rtthread.bin
scons
将生成的rtthread.bin用虚拟磁盘方式烧录进去，可以看到有wavplay和wavrecord命令：
msh />wavplay -h
usage: wavplay [option] [target] ...
usage options:
-h, --help Print defined help message.
-s URI, --start=URI Play wav music with URI(local files).
-t, --stop Stop playing music.
-p, --pause Pause the music.
-r, --resume Resume the music.
-v lvl, --volume=lvl Change the volume(0~99).
-d, --dump Dump play relevant information.
msh />wavrecord -h
usage: wavrecord [option] [target] ...
usage options:
-h, --help Print defined help message.
-s file --start=file
record wav music to filesystem.
-t, --stop Stop record.
4.2 挂载elm文件系统
wavrecord录制wav文件到文件系统上，elm是fatfs文件系统。
msh />mkfs -t elm flash0
msh />mount flash0 / elm
mount device flash0(elm) onto / ... succeed!
msh />mount
filesystem device mountpoint

devfs (NULL) /dev
elm flash0 /
mkfs -t elm flash0: 对设备flash0制作elm文件系统
mount flash0 / elm: 挂载设备flash0到/节点上，该设备是elm文件系统
4.3 录音测试
wavrecord -s /test.wav 8000 2 16: 开始录音，PCM格式为采样率8K/双通道/16bit精度，封装格式为WAV。
wavrecord -t：停止录音
演示：
msh />wavrecord -s /test.wav 8000 2 16
[I/i2s] Stop record.
[I/i2s] Close I2S.
[I/acodec.nau88l25] Software Reset.
[I/acodec.nau88l25] Initialized done.
[I/i2s] Open I2S.
[W/i2s] Real sample rate: 46875 Hz != preferred sample rate: 48000 Hz
[I/i2s] Start record.
Information:
samplerate 8000
channels 2
[I/i2s] Stop record.
[I/i2s] Close I2S.
[I/acodec.nau88l25] Software Reset.
[I/acodec.nau88l25] Initialized done.
[I/i2s] Open I2S.
[W/i2s] Real sample rate: 8152 Hz != preferred sample rate: 8000 Hz
[I/i2s] Start record.
msh />
msh />wavrecord -t
[I/i2s] Stop record.
[I/i2s] Close I2S.
msh />ls
Directory /:
test.wav 442412
通过ls命令查看到test.wav文件。
4.4 播放测试
播放录音文件test.wav
wavplay -s /test.wav: 开始播放test.wav文件，wav封装头中有音频的采样率/通道/精度，不用再指定这些参数；
演示：
msh />wavplay -s /test.wav
[I/WAV_PLAYER] play start, uri=/test.wav
[I/i2s] Stop replay.
[I/i2s] Close I2S.
[I/acodec.nau88l25] Software Reset.
[I/acodec.nau88l25] Initialized done.
[I/i2s] Open I2S.
[W/i2s] Real sample rate: 8152 Hz != preferred sample rate: 8000 Hz
[I/i2s] Start replay.
[I/i2s] Stop replay.
[I/i2s] Close I2S.
[I/WAV_PLAYER] play end
这里可以手动在发命令结束播放，也可以等待播放完毕。
wavplay -t: 结束播放；
演示：
msh />wavplay -s /test.wav
[I/WAV_PLAYER] play start, uri=/test.wav
[I/i2s] Stop replay.
[I/i2s] Close I2S.
[I/acodec.nau88l25] Software Reset.
[I/acodec.nau88l25] Initialized done.
[I/i2s] Open I2S.
[W/i2s] Real sample rate: 8152 Hz != preferred sample rate: 8000 Hz
[I/i2s] Start replay.
msh />wavplay -t
[I/i2s] Stop replay.
[I/i2s] Close I2S.
[I/WAV_PLAYER] play end
wavplay -v 70: 在正在播放时，可以调节音量，比如70
msh />wavplay -v 70
[I/WAV_PLAYER] set volume = 70
这里有”[I/WAV_PLAYER] set volume = 70”这句打印需要修改wavplayer.c中wavplayer_volume_set里的打印LOG_D为LOG_I。
wavplay -p: 暂停播放；
wavplay -r: 恢复播放；
5 测试结果
这里总体音频测试结果不是很理想，主要现象表现为播放时有时声音时正常的，有时都是全是噪音或变调；

参数
结果(测十次)
测试命令

8000/1/16
3次有声音(环境噪明显), 7次全噪
wavrecord -s 8000_1.wav 8000 1; wavrecord -t; wavplay -s 8000_1.wav

8000/2/16
6次正常，4次全是噪声
wavrecord -s 8000_2.wav 8000 2; wavrecord -t; wavplay -s 8000_2.wav

16000/1/16
5次正常，5次全是噪声
wavrecord -s 16000_1.wav 16000 1; wavrecord -t; wavplay -s 16000_1.wav

16000/2/16
5次正常，5次全是噪声
wavrecord -s 16000_2.wav 16000 2; wavrecord -t; wavplay -s 16000_2.wav

44100/1/16
5次变调加噪声，5次全是噪声
wavrecord -s 44100_1.wav 44100 1; wavrecord -t; wavplay -s 44100_1.wav

44100/2/16
5次变调，5次全是噪声
wavrecord -s 44100_2.wav 44100 2; wavrecord -t; wavplay -s 44100_2.wav

48000/1/16
1次变调加噪声，9次全是噪声
wavrecord -s 48000_1.wav 48000 1; wavrecord -t; wavplay -s 48000_1.wav

48000/2/16
1次变调加噪声，9次全是噪声
wavrecord -s 48000_2.wav 48000 2; wavrecord -t; wavplay -s 48000_2.wav

原作者：rt_wei