• PCM Wave Player Super Lite with Nim language on STM32 MCUs
  • Supported Board/MCU
  • Supported SD card
  • Supported PCM Format
  • Default action
  • Hardware setting/Schematic: (16bit sound resolution)
  • SD Card connection
  • PWM output port
  • LED indicator
  • Nim compiler
  • C compiler: arm-none-eabi-gcc
  • Compiling source code
  • Output music filename through UART port
  • Simple less bits mode
  • Pursue small code size
  • Other links

PCM Wave Player Super Lite with Nim language on STM32 MCUs

---

16bit resolution PWM wave player with SD card, super lite version.

Music by Audionautix.com

Supported Board/MCU

---

MCU	Boards
STM32F0	NULCEO-F030R8 STM32F0Discovery
STM32L1	NUCLEO-L152RE
STM32F3	STM32F3Discovery
STM32F4	NULCEO-F401RE NULCEO-F411RE

Supported SD card

---

• SDSC/SDHC card, FAT16 and FAT32.
  1. At first, format SD card with SD Card Formatter
  2. Copy PCM wav files to the SD card on the root directory.

Supported PCM Format

---

• PCM wav file that have file extension ".wav" on root directory.
• 16bit/8bit, fs(sampling rate)=32kHz,44.1kHz,48kHz.
• Stereo/Mono.

Default action

---

• After power on, loop playback automatically and infinitly.
• USER_BUTTON on board operation: (PC_13 or PA_0)
  • Next song: One click in Play mode.
  • Pause : Push long time .
  • Play : One click from Pause.

Hardware setting/Schematic: (16bit sound resolution)

---

• Refer to the file, port_setting.md.
• See folder doc/*
  

SD Card connection

---

Pin side
 --------------.
         9     = \   DAT2/NC
             1 ===|  CS/DAT3    [CS]
             2 ===|  CMD/DI     [DI]
             3 ===|  VSS1
 Bottom      4 ===|  VDD
 View        5 ===|  CLK        [CLK]
             6 ===|  VSS2
             7 ===|  DO/DAT0    [DO]
         8       =|  DAT1/IRQ
 -----------------'
                                                 NUCLEO-F030R8
                                       Arduino   NUCLEO-F411   
 Logo side
 -----------------.
         8       =|  DAT1/IRQ
             7 ===|  DO/DAT0    [DO]   D12        D12/PA_6      
             6 ===|  VSS2
 Top         5 ===|  CLK        [CLK]  D13        D13/PA_5      
 View        4 ===|  VDD
             3 ===|  VSS1
             2 ===|  CMD/DI     [DI]   D11        D11/PA_7      
             1 ===|  CS/DAT3    [CS]   D8         D10/PB_6      
         9     = /   DAT2/NC
 ---------------'

PWM output port

---

• Left upper(Hi) PWM 8bit out: PB_5 (TM3_CH2)
• Right upper(Hi) PWM 8bit out: PB_4 (TM3_CH1)
• Left lower(Low) PWM 8bit out: PC_9 (TM3_CH4)
• Right lower(Low) PWM 8bit out: PC_8 (TM3_CH3)

LED indicator

---

• See port_setting.md.
• If set up LED device to "LED indicator port", it will be dimmer during play mode (regular speed) and pause mode (fast speed).

Nim compiler

---

• Recomended nim compiler version is nim-1.6.12 at this time.

C compiler: arm-none-eabi-gcc

---

• v4.8.3 or later.
• Recomend GNU Arm Embedded Toolchain

Compiling source code

---

• Example: (NUCLEO-F411RE board)

  $ cd src/F4/f401xe/nucleo-f411re
  $ make
  .........................................................
  CC: xprintf
  CC: startup_stm32f411xe
  CC: stdlib_system.nim
  CC: ../stm32f401xe.nim
  CC: ../../../lib/reginfo.nim
  CC: ../uart.nim
  CC: ../pwm.nim
  CC: board.nim
  CC: ../spi.nim
  CC: ../../../lib/systick.nim
  CC: ../../../lib/sd_card.nim
  CC: ../../../lib/fat_lib.nim
  CC: ../../../wave_player_main.nim
  CC: ../../../main.nim
  CC: start.nim
  Hint:  [Link]
  Hint: gc: arc; opt: speed; options: -d:danger
  90709 lines; 11.377s; 96.109MiB peakmem; proj: .\start; out: ...
     text    data     bss     dec     hex filename
     4148      16      88    4252    109c BINHEX\nucleo_f411re.elf

  Generated files are

  BINHEX/nucleo_f411re.bin  
  BINHEX/nucleo_f411re.hex  
  ...
  

You can just copy the bin file to mbed drive,
or can flash the hex file with ST-Link utility.

If you don't like to compile from source code, you can immediately upload doc/hex/*.hex or *.bin files to flash.

Output music filename through UART port

---

By default music filename is send through default UART(USB-CDC on Nucleo boards) port.
Baudrate is 115200bps.

If you don't need UART output feature, set UART_INFO* = false in src/conf_sys.nim and
recompile the project.

Simple less bits mode

---

If set PWM16BIT* = false in src/conf_sys.nim and recompile the project, simple less bits mode is enabled.
In spite of less parts, wirings and PCM bit length, it has fairly sound quality.

Table 1. Sound resolution in simple less bits mode

Board	Sound resolution	TIM_PWM_BASE_CLOCK
nulceo_f030r8	10bit	48MHz
nucleo_l152re	9bit	32MHz
nulceo_f401re	10bit	84MHz
nulceo_f411re	11bit	96MHz
STM32F0Discovery	10bit	48MHz
STM32F3Discovery	10bit	64MHz
STM32F4Discovery	10bit	84MHz

Pursue small code size

---

In src/conf_sys.nim,by eliminating some functionalities,
the code size can be further reduced. For instance, set as follows:

Flags	Descriptions
UART_INFO* = false	Not show information through UART
PWM16BIT* = false	Enable simple less bits mode
DATA_8BIT_SUPPORT* = false	Not support PCM 8bit data format
HAVE_LED_IND_PWM* = false	Not support LED indicator functionality
FS_48KHZ_QUP* = false	Not support quality up at fs=48KHz

would result in about

text    data     bss     dec     hex filename
3480      16      80    3576     df8 BINHEX\nucleo_f411re.elf

Now it can do auto playback after power on,
operate play,pause and next song with push button,
play fairly quality sound according to Table 1,
recognize PCM 16bit wav file (but sound quality is reduced accoding to Table 1.)
and support stereo/mono, fs=32KHz,44.1KHz.

Other links

---

• Wave player project, Super lite series
  • Nim language
    Arduino Wave Player PWM Super Lite Nim / Nim (Completed.)
  • Mbed2 C/C++ language
    Wave Player Super Lite / STM32(F0,L1,F4) / Mbed2 / C++ (Completed.)
  • Jal language
    Pwm Wave Player Jalv2 / PIC16F1xxx / Jal (Completed.)