【STM32N6570-DK测评】音频录制与播放

只看该作者 · 2025-5-11 21:51

这个功能其实笔者已经实现，而且用的就是ST的测试用例，前面RNNOISE降噪的测评文章提到过。但那篇文章没有显式的提出，这里单独出一篇帖子简单提一提。

众所周知，STM32N6系列集成有MDF(Multi-function digital filter),然后阅读原理图发现STM32N6570-DK又板载了一颗MEMS芯片：MP23DB01HP，这是ST家的传感器产品之一，两者配合就可以做到录音功能了。

就播放来说，也很简单。原理图显示，STM32N6570-DK板载了一颗WM8904解码芯片，并有模拟信号上的耳机和喇叭接口，所以预先设置下WM8904芯片参数，然后pcm数据发SAI通道就能做到声音的播放了。

笔者用的是耳机通道

事实上STM32Cube_FW_N6中的一个测试用例（Projects/STM32N6570-DK/Examples/MDF/MDF_AudioRecorder/）展示了录音和播放的效果。它的主要过程是：

配置MDF、配置DMA、配置WM8904和SAI，然后开启MDF的DMA录音，一旦麦克风录到数据就由DMA搬运PcmBuffer中，再由SAI的DMA把PCM数据发SAI，如此循环往复。

这个测试用例是N6多媒体样例中最简单的，所以笔者之前并未单独列一篇测评文章给它，但它基本把音频录制和播放都展示了一遍，简单直接，大伙都喜欢。

另外笔者也未拉起CubeMX这样的大杀器，而是直接写了个CMakeLists.txt文件，这里贴出来和读者分享:

复制

set(CMAKE_SYSTEM_NAME Generic)

set(CMAKE_SYSTEM_VERSION 1)

set(CMAKE_TRY_COMPILE_TARGET_TYPE "STATIC_LIBRARY")

cmake_minimum_required(VERSION 3.20)



set(CMAKE_C_COMPILER arm-none-eabi-gcc)

set(CMAKE_CXX_COMPILER arm-none-eabi-g++)

set(CMAKE_ASM_COMPILER arm-none-eabi-gcc)

set(CMAKE_AR arm-none-eabi-ar)

set(CMAKE_OBJCOPY arm-none-eabi-objcopy)

set(CMAKE_OBJDUMP arm-none-eabi-objdump)

set(SIZE arm-none-eabi-size)



set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)

set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)

set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)



add_compile_options(-mthumb -mcpu=cortex-m55 -mfloat-abi=hard -mfpu=fpv5-d16 -mcmse)

add_compile_options(-ffunction-sections -fdata-sections -fno-builtin -fno-common -Wall -Wshadow -Wdouble-promotion -Werror -Wno-unused-parameter)



add_compile_options(-O2)



project(stm32n6 C ASM)

set(CMAKE_CXX_STANDARD 11)

set(CMAKE_C_STANDARD 99)



include_directories(Drivers/CMSIS/Include

                    Drivers/CMSIS/Device/ST/STM32N6xx/Include

                    Drivers/STM32N6xx_HAL_Driver/Inc

                    Drivers/BSP/STM32N6570-DK

                    Drivers/BSP/Components/wm8904

                    Drivers/BSP/Components/Common

                    Projects/STM32N6570-DK/Examples/MDF/MDF_AudioRecorder/FSBL/Inc)



add_definitions(-DSTM32N657xx)



file(GLOB_RECURSE SOURCES

                "Drivers/STM32N6xx_HAL_Driver/Src/*.c"

                "Drivers/BSP/STM32N6570-DK/stm32n6570_discovery.c"

                "Drivers/BSP/STM32N6570-DK/stm32n6570_discovery_bus.c"

                "Drivers/BSP/Components/wm8904/*.c"

                "Projects/STM32N6570-DK/Examples/MDF/MDF_AudioRecorder/FSBL/Src/*.c"

                "Projects/STM32N6570-DK/Examples/MDF/MDF_AudioRecorder/STM32CubeIDE/FSBL/Application/User/*.c"

                "Projects/STM32N6570-DK/Examples/MDF/MDF_AudioRecorder/STM32CubeIDE/FSBL/Application/Startup/startup_stm32n657x0hxq_fsbl.s"

                )



set(LINKER_SCRIPT ${CMAKE_SOURCE_DIR}/Projects/STM32N6570-DK/Examples/BSP/STM32CubeIDE/FSBL/STM32N657X0HXQ_AXISRAM2_fsbl.ld)

add_link_options(

                -mthumb -mcpu=cortex-m55 -mfloat-abi=hard -mfpu=fpv5-d16 -mcmse

                -Wl,--gc-sections,--print-memory-usage,-Map,${PROJECT_NAME}.map

                --specs=nano.specs

                --specs=nosys.specs)

add_link_options(-T ${LINKER_SCRIPT})



add_executable(${PROJECT_NAME}.elf ${SOURCES} ${LINKER_SCRIPT})



# target_link_libraries(${PROJECT_NAME}.elf printfloat)



set(HEX_FILE ${PROJECT_BINARY_DIR}/${PROJECT_NAME}.hex)

set(BIN_FILE ${PROJECT_BINARY_DIR}/${PROJECT_NAME}.bin)

set(LST_FILE ${PROJECT_BINARY_DIR}/${PROJECT_NAME}.lst)

add_custom_command(TARGET ${PROJECT_NAME}.elf POST_BUILD

        COMMAND ${CMAKE_OBJCOPY} -Oihex [        DISCUZ_CODE_2        ]lt;TARGET_FILE:${PROJECT_NAME}.elf> ${HEX_FILE}

        COMMAND ${CMAKE_OBJCOPY} -Obinary [        DISCUZ_CODE_2        ]lt;TARGET_FILE:${PROJECT_NAME}.elf> ${BIN_FILE}

        COMMAND ${CMAKE_OBJDUMP} --all-headers --demangle --disassemble [        DISCUZ_CODE_2        ]lt;TARGET_FILE:${PROJECT_NAME}.elf> > ${LST_FILE}

        COMMAND ${SIZE} --format=berkeley [        DISCUZ_CODE_2        ]lt;TARGET_FILE:${PROJECT_NAME}.elf>

)