STM32之MicroPython

发表于 2021-07-28 更新于 2023-08-22 分类于编程开发， python ， usages

买了2块mini开发板，一块STM32F407VE，另一块STM32H743VI。无他，唯体积小。看到OpenMV大行其道，开始折腾MicroPython。

环境： Ubuntu 16.04 x64
开发板： DevEBox STM32H7XX_M Ver:V2.0 SN:1907

STM32H743VI开发板外观如下（STM32F407VE板样子都一样）。

1、安装`make`和`gcc`

# 安装gcc相关
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update 
# 顺便安装g++-9
sudo apt-get install make gcc-9 g++-9

# 安装交叉编译相关
sudo add-apt-repository ppa:team-gcc-arm-embedded/ppa
sudo apt update
sudo apt install gcc-arm-embedded

2、下载`micropython`源码

cd <SRC_ROOT>
git clone https://github.com/micropython/micropython.git
cd micropython
git submodule update --init

# （更新）拉取远程库
# git pull --progress -v --no-rebase "origin"

3、下载开发板的配置代码

cd <SRC_ROOT>/micropython/ports/stm32/boards
# H743的移植文件
git clone https://github.com/mcauser/MCUDEV_DEVEBOX_H7XX_M.git

# F407VE的一移植文件
# git clone https://github.com/mcauser/MCUDEV_DEVEBOX_F407VET6.git

# 修改后：
#  H743: https://github.com/njuFerret/MCUDEV_DEVEBOX_H7XX_M.git
#  F407Ve https://github.com/njuFerret/MCUDEV_DEVEBOX_F407VET6

此处编译出错，按照MCUDEV_DEVEBOX_H7XX_M中的Issues/1说明，编辑 MCUDEV_DEVEBOX_H7XX_M/mpconfigboard.h如下：

/*-----------------------------------原定义----------------------------------------*/
// // HSE is 25MHz
// #define MICROPY_HW_CLK_PLLM (25) // divide external clock by this to get 1MHz
// #define MICROPY_HW_CLK_PLLN (160) // PLL clock in MHz
// #define MICROPY_HW_CLK_PLLP (RCC_PLLP_DIV2) // divide PLL clock by this to get core clock
// #define MICROPY_HW_CLK_PLLQ (4) // divide core clock by this to get 40MHz

/*---------------------------------修改后定义---------------------------------------*/
// The board has an 25MHz HSE, the following gives 480MHz CPU speed
#define MICROPY_HW_CLK_PLLM (5)
#define MICROPY_HW_CLK_PLLN (192)
#define MICROPY_HW_CLK_PLLP (2)
#define MICROPY_HW_CLK_PLLQ (5)
#define MICROPY_HW_CLK_PLLR (2)

// The USB clock is set using PLL3
#define MICROPY_HW_CLK_PLL3M (5)
#define MICROPY_HW_CLK_PLL3N (48)
#define MICROPY_HW_CLK_PLL3P (2)
#define MICROPY_HW_CLK_PLL3Q (5)
#define MICROPY_HW_CLK_PLL3R (2)

4、编译

cd <SRC_ROOT>/micropython
make -C mpy-cross
cd ports/stm32
make submodules
make BOARD=MCUDEV_DEVEBOX_H7XX_M clean
make BOARD=MCUDEV_DEVEBOX_H7XX_M

5、烧入开发板

编译完成后，在micropython/ports/stm32目录下会出现build-MCUDEV_DEVEBOX_H7XX_M目录，找到固件文件firmware.hex，使用STM32 ST-LINK Utility烧入即可。

烧写完成后出现low power的情况，插入usb之后会出现windows安装设备等提示，以一个U盘形式出现。

6、使用方法

两种模式，解释器模式和文件模式。前者使用putty打开串口，与其他解释器一样使用。后者直接修改main.py文件。IDE方面，VScode略显不便，可以采用Thonny，写完代码可以直接烧入开发板，比较方便。

7、例子

查看当前运行主频：

import machine
machine.freq()

# 或
#>>> import pyb
#>>> pyb.freq()
#(480000000, 240000000, 120000000, 120000000)

首先点个灯：

import pyb

tim = pyb.Timer(4,freq=2)	# 2Hz ,500ms
tim.callback(lambda t:pyb.LED(1).toggle())
# tim.callback(None) # 停止回调

如果用sleep函数，必须等待其执行完成，或 Ctrl+C终止执行

import time
>>> for _ in range(30):
...     pyb.LED(1).toggle()
...     time.sleep(0.5)

再来一个PWM：

import pyb 

p = pyb.Pin('D12')	# Tim4, PWM ch1, PD12
tim = pyb.Timer(4, freq=1000)
ch = tim.channel(1, pyb.Timer.PWM, pin=p)
ch.pulse_width_percent(50)

8、使用板载`Flash` vs `MCU`内置`Flash`

上述编译中，使用的是MCU内置flash，hex固件约1.26M，烧完之后，几乎没啥空间了，考虑折腾板载的外置Flash。

H7xx开发板板载一颗W25Q64的8MByte flash，F407开发板板载的是W25Q16的2MByte flash。前者支持QSPI，后者不支持。

SPI协议包括：Standard SPI、Dual SPI和Queued SPI三种协议，分别对应3-wire, 4-wire, 6-wire。

Standard SPI，有4根信号线，分别为CLK、CS、MOSI和MISO。数据线工作在全双工。

Dual SPI，只针对SPI Flash而言，不是针对所有SPI外设。对于SPI Flash，全双工并不常用，因此扩展了mosi和miso的用法，让它们工作在半双工，用以加倍数据传输。也就是对于Dual SPI Flash，可以发送一个命令字节进入dual mode，这样mosi变成SIO0（serial io 0），mosi变成SIO1（serial io 1）,这样一个时钟周期内就能传输2个bit数据，加倍了数据传输。

类似的，QSPI也是针对SPI Flash，Qual SPI Flash增加了两根I/O线（SIO2,SIO3），目的是一个时钟内传输4个bit

8.1 增加管脚定义

micropython自带的PYBD_SF开发板是很好的参考资料，位于ports\stm32\boards\PYBD_SF2

可参考ports/stm32/boards/PYBD_SF2中相关内容

也可参考 MCUDEV_DEVEBOX_F407VET6中相关内容

打开MCUDEV_DEVEBOX_H7XX_M/mpconfigboard.h，增加如下内容：

// 1 = use internal flash (2048 KByte)
// 0 = use onboard SPI flash (8 MByte) Winbond W25Q64 with QSPI
#define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE (0)

// If using onboard SPI flash
#if !MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE

#define MICROPY_HW_SPIFLASH_ENABLE_CACHE (1)

// Winbond W25Q16 SPI Flash = 64 Mbit (8 MByte)
#define MICROPY_HW_SPIFLASH_SIZE_BITS (64 * 1024 * 1024)
#define MICROPY_HW_QSPIFLASH_SIZE_BITS_LOG2 (26)
// 引脚参照原理图
#define MICROPY_HW_QSPIFLASH_CS         (pin_B6)
#define MICROPY_HW_QSPIFLASH_SCK        (pin_B2)
#define MICROPY_HW_QSPIFLASH_IO0        (pin_D11)
#define MICROPY_HW_QSPIFLASH_IO1        (pin_D12)
#define MICROPY_HW_QSPIFLASH_IO2        (pin_E2)
#define MICROPY_HW_QSPIFLASH_IO3        (pin_D13)

#define MICROPY_BOARD_EARLY_INIT    Mcudev_Devebox_H743VI_board_early_init
void Mcudev_Devebox_H743VI_board_early_init(void);

extern const struct _mp_spiflash_config_t spiflash_config;
extern struct _spi_bdev_t spi_bdev;
#define MICROPY_HW_BDEV_IOCTL(op, arg) ( \
    (op) == BDEV_IOCTL_NUM_BLOCKS ? (MICROPY_HW_SPIFLASH_SIZE_BITS / 8 / FLASH_BLOCK_SIZE) : \
    (op) == BDEV_IOCTL_INIT ? spi_bdev_ioctl(&spi_bdev, (op), (uint32_t)&spiflash_config) : \
    spi_bdev_ioctl(&spi_bdev, (op), (arg)) \
)

#define MICROPY_HW_BDEV_READBLOCKS(dest, bl, n) spi_bdev_readblocks(&spi_bdev, (dest), (bl), (n))
#define MICROPY_HW_BDEV_WRITEBLOCKS(src, bl, n) spi_bdev_writeblocks(&spi_bdev, (src), (bl), (n))

#endif

8.2 补全`QSPI`实现函数

增加bdev.c和board_init.c文件

// bdev.c

#include "storage.h"

#if !MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE

// External SPI flash uses QSPI interface
STATIC const mp_soft_qspi_obj_t qspi_bus = {
    .cs  = MICROPY_HW_QSPIFLASH_CS,
    .clk = MICROPY_HW_QSPIFLASH_SCK,
    .io0 = MICROPY_HW_QSPIFLASH_IO0,
    .io1 = MICROPY_HW_QSPIFLASH_IO1,
    .io2 = MICROPY_HW_QSPIFLASH_IO2,
    .io3 = MICROPY_HW_QSPIFLASH_IO3,
};

STATIC mp_spiflash_cache_t spi_bdev_cache;

const mp_spiflash_config_t spiflash_config = {
    .bus_kind = MP_SPIFLASH_BUS_QSPI,
    .bus.u_qspi.data = (void*)&qspi_bus,
    .bus.u_qspi.proto = &mp_soft_qspi_proto, 
#if MICROPY_HW_SPIFLASH_ENABLE_CACHE
    .cache = &spi_bdev_cache,
#endif
};

spi_bdev_t spi_bdev;

#endif

// board_init.c

#include "py/mphal.h"

void Mcudev_Devebox_H743VI_board_early_init(void) {
#include "py/mphal.h"

void Mcudev_Devebox_H743VI_board_early_init(void) {
    // set SPI flash CS pin high
    // mp_hal_pin_output(pin_A15);
    // mp_hal_pin_write(pin_A15, 0);
}

8.3 补全管脚定义

打开MCUDEV_DEVEBOX_H7XX_M/pins.csv，增加如下内容

QSPIFLASH_CS,PB6
QSPIFLASH_SCK,PB2
QSPIFLASH_IO0,PD11
QSPIFLASH_IO1,PD12
QSPIFLASH_IO2,PE2
QSPIFLASH_IO3,PD13

8.4 编译

可根据情况，选取是否使用SPI Flash，修改宏定义后，重新编译即可。

1
2
3

// 1 = use internal flash (2048 KByte)
// 0 = use onboard SPI flash (8 MByte) Winbond W25Q64 with QSPI
#define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE (0)

9、 `Mini F407VE`板

F407VE板已经自带了bdev.c和board_init.c，只是缺少一个开启cache的宏，可以参考PYBD_SF2在bdev.c中分开加，也可以参考STM32L476DISC在mpconfigboard.h中一次性加入。
另外需要注意的是，F407VE板使用的是标准SPI，可以直接copySTM32L476DISC内容，只是需要增加一个开启关闭使用外部Flash的宏，最后注意SPI低电平有效，需要预先将管脚位置低。

最后放上patch。

 board_init.c    |  3 ++-
 mpconfigboard.h | 19 +++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/board_init.c b/board_init.c
index c60141e..896f698 100644
--- a/board_init.c
+++ b/board_init.c
@@ -3,5 +3,6 @@
 void Mcudev_Devebox_F407VE_board_early_init(void) {
     // set SPI flash CS pin high
     mp_hal_pin_output(pin_A15);
-    mp_hal_pin_write(pin_A15, 1);
+    // mp_hal_pin_write(pin_A15, 1);
+    mp_hal_pin_write(pin_A15, 0);
 }
diff --git a/mpconfigboard.h b/mpconfigboard.h
index 13f6306..e7a2b31 100644
--- a/mpconfigboard.h
+++ b/mpconfigboard.h
@@ -1,10 +1,6 @@
 #define MICROPY_HW_BOARD_NAME       "MCUDEV DEVEBOX STM32F407VE"
 #define MICROPY_HW_MCU_NAME         "STM32F407VE"
-#define MICROPY_HW_FLASH_FS_LABEL   "DEVEBOXF407VE"
-
-// 1 = use internal flash (512 KByte)
-// 0 = use onboard SPI flash (2 MByte) Winbond W25Q16
-#define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE (1)
+#define MICROPY_HW_FLASH_FS_LABEL   "MiniF407VE"
 
 #define MICROPY_HW_HAS_SWITCH       (1)		// has 1 button KEY0
 #define MICROPY_HW_HAS_FLASH        (1)
@@ -15,9 +11,9 @@
 #define MICROPY_HW_ENABLE_SDCARD    (0)		// it has a sd scard, but i am not sure what the detect pin is, yet
 
 // HSE is 8MHz
-#define MICROPY_HW_CLK_PLLM (8) // divide external clock by this to get 1MHz
-#define MICROPY_HW_CLK_PLLN (336) // PLL clock in MHz
-#define MICROPY_HW_CLK_PLLP (RCC_PLLP_DIV2) // divide PLL clock by this to get core clock
+#define MICROPY_HW_CLK_PLLM (4) // divide external clock by this to get 1MHz
+#define MICROPY_HW_CLK_PLLN (168) // PLL clock in MHz
+#define MICROPY_HW_CLK_PLLP (2) // divide PLL clock by this to get core clock
 #define MICROPY_HW_CLK_PLLQ (7) // divide core clock by this to get 48MHz
 
 // The board has a 32kHz crystal for the RTC
@@ -106,9 +102,16 @@
 #define MICROPY_HW_LED_ON(pin)      (mp_hal_pin_low(pin))
 #define MICROPY_HW_LED_OFF(pin)     (mp_hal_pin_high(pin))
 
+// 1 = use internal flash (512 KByte)
+// 0 = use onboard SPI flash (2 MByte) Winbond W25Q16
+#define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE (0)
+
 // If using onboard SPI flash
 #if !MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE
 
+// fix "error: unknown type name 'mp_spiflash_cache_t'"
+#define MICROPY_HW_SPIFLASH_ENABLE_CACHE (1)
+
 // Winbond W25Q16 SPI Flash = 16 Mbit (2 MByte)
 #define MICROPY_HW_SPIFLASH_SIZE_BITS (16 * 1024 * 1024)
 #define MICROPY_HW_SPIFLASH_CS      (pin_A15)

参考

https://blog.csdn.net/liaoze22/article/details/106708796
https://blog.csdn.net/wangguchao/article/details/105593303

1、安装make和gcc

2、下载micropython源码