开发环境

芯片：STM32H750XBH6
开发板：ART-Pi
RT-Thread Studio: V2.0.0
RT-Thread版本：V4.0.3
STM32 CubeMX: V6.1.1

创建项目

RT-Thread Studio中点击菜单 文件-新建-RT-Thread项目，选择基于ART-Pi 开发板的模板工程。

步骤1：RT-Thread Studio项目设置

在设置中启用HWTIMER和PWM设备驱动。
双击项目的RT-Thread Setting，点击右侧箭头

在组件-设备驱动程序中，打开使用HWTIMER设备驱动程序和使用PWM设备驱动程序。

此时我们看到\board\CubeMX_Config\Core\Inc\stm32h7xx_hal_conf.h文件中，
已经启用了两个宏定义:

#define HAL_TIM_MODULE_ENABLED

和

#define HAL_PWR_MODULE_ENABLED

如未启用，请手动取消这两行的注释。

步骤2：打开board.h宏定义

本例打开PI5的PWM输出，对应PWM8的CH1。
在board\board.h中添加如下宏定义：

#define BSP_USING_PWM8
#define BSP_USING_PWM8_CH1
#define BSP_USING_TIM8

步骤3：STM32CubeMX(或者STM32CubeIDE)配置

3.0 新建基于STM32H750XBHx的项目。

3.1 在Pinout view中配置PI5为TIM8_CH1

3.2 配置时钟

3.3 RCC中配置使用外部高速晶振HSE

3.4 TIM8配置CH1

TIM8启用CH1
Prescaler设置为240-1
Counter Period设置为1000-1
这样将PWM频率设为1KHz

3.5 设置代码输出选项

在Project Manager的Code Generator中，选中Generate peripheral initialization as a pair of '.c/.h' files per peripheral

3.6 点击Generate Code

4. 修改board.c和board.h

打开cubeMX导出代码中的Core\Src\tim.c文件
将htim8的声明和如下三个函数复制粘贴到RT-Thread 项目中的board\board.c文件中

TIM_HandleTypeDef htim8;
void MX_TIM8_Init(void)
void HAL_TIM_PWM_MspInit(TIM_HandleTypeDef* htim_pwm)
void HAL_TIM_MspPostInit(TIM_HandleTypeDef* htim)
void HAL_TIM_PWM_MspDeInit(TIM_HandleTypeDef* htim_pwm)

具体函数实现如下（会根据不同的GPIO和PWM Channel有所差异）。

TIM_HandleTypeDef htim8;
void MX_TIM8_Init(void)
{
    
  TIM_MasterConfigTypeDef sMasterConfig = {
    0};
  TIM_OC_InitTypeDef sConfigOC = {
    0};
  TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {
    0};

  htim8.Instance = TIM8;
  htim8.Init.Prescaler = 240-1;
  htim8.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim8.Init.Period = 1000-1;
  htim8.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim8.Init.RepetitionCounter = 0;
  htim8.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_PWM_Init(&htim8) != HAL_OK)
  {
    
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim8, &sMasterConfig) != HAL_OK)
  {
    
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 0;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_LOW;
  sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
  sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
  if (HAL_TIM_PWM_ConfigChannel(&htim8, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    
    Error_Handler();
  }
  sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
  sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
  sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
  sBreakDeadTimeConfig.DeadTime = 0;
  sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
  sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
  sBreakDeadTimeConfig.BreakFilter = 0;
  sBreakDeadTimeConfig.Break2State = TIM_BREAK2_DISABLE;
  sBreakDeadTimeConfig.Break2Polarity = TIM_BREAK2POLARITY_HIGH;
  sBreakDeadTimeConfig.Break2Filter = 0;
  sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
  if (HAL_TIMEx_ConfigBreakDeadTime(&htim8, &sBreakDeadTimeConfig) != HAL_OK)
  {
    
    Error_Handler();
  }
  HAL_TIM_MspPostInit(&htim8);

}
void HAL_TIM_PWM_MspInit(TIM_HandleTypeDef* htim_pwm)
{
    
  if(htim_pwm->Instance==TIM8)
  {
    
  /* USER CODE BEGIN TIM5_MspInit 0 */

  /* USER CODE END TIM5_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_TIM8_CLK_ENABLE();
  /* USER CODE BEGIN TIM5_MspInit 1 */

  /* USER CODE END TIM5_MspInit 1 */
  }

}

void HAL_TIM_MspPostInit(TIM_HandleTypeDef* htim)
{
    
  GPIO_InitTypeDef GPIO_InitStruct = {
    0};
  if(htim->Instance==TIM8)
  {
    
    /* USER CODE BEGIN TIM8_MspPostInit 0 */

    /* USER CODE END TIM8_MspPostInit 0 */

      __HAL_RCC_GPIOI_CLK_ENABLE();
      /**TIM8 GPIO Configuration
      PI5     ------> TIM8_CH1
      */
      GPIO_InitStruct.Pin = GPIO_PIN_5;
      GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
      GPIO_InitStruct.Pull = GPIO_NOPULL;
      GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
      GPIO_InitStruct.Alternate = GPIO_AF3_TIM8;
      HAL_GPIO_Init(GPIOI, &GPIO_InitStruct);

    /* USER CODE BEGIN TIM8_MspPostInit 1 */

    /* USER CODE END TIM8_MspPostInit 1 */
    }

}
/**
* @brief TIM_PWM MSP De-Initialization
* This function freeze the hardware resources used in this example
* @param htim_pwm: TIM_PWM handle pointer
* @retval None
*/
void HAL_TIM_PWM_MspDeInit(TIM_HandleTypeDef* htim_pwm)
{
    
  if(htim_pwm->Instance==TIM8)
  {
    
  /* USER CODE BEGIN TIM5_MspDeInit 0 */

  /* USER CODE END TIM5_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_TIM8_CLK_DISABLE();
  /* USER CODE BEGIN TIM5_MspDeInit 1 */

  /* USER CODE END TIM5_MspDeInit 1 */
  }

}

然后修改board\board.h，添加如下几行:

void MX_TIM8_Init(void);
void HAL_TIM_PWM_MspInit(TIM_HandleTypeDef* htim_pwm);
void HAL_TIM_PWM_MspDeInit(TIM_HandleTypeDef* htim_pwm);
void HAL_TIM_MspPostInit(TIM_HandleTypeDef* htim);

5. 修改main.c

main.c代码使用一个线程来调节PWM输出，注意首先要导入
board.h头文件，并在main函数中调用MX_TIM8_Init();。

#include <rtthread.h>
#include <rtdevice.h>
#include "drv_common.h"
#include "board.h"

#define LOG_TAG              "thread_app"
#define LOG_LVL              LOG_LVL_DBG
#include <ulog.h>


#define THREAD_PRIORITY         25
#define THREAD_STACK_SIZE       512
#define THREAD_TIMESLICE        5

#define PWM_DEV_NAME        "pwm8"  /* PWM设备名称 */
#define PWM_DEV_CHANNEL     1       /* PWM通道 */
struct rt_device_pwm *pwm_dev;      /* PWM设备句柄 */

static rt_thread_t pwm_tid;

static void pwm_thread_entry(void *parameter)
{
    
    rt_uint32_t period, pulse, dir;
        period = 1000000;    /* 1KHz周期为1ms,这里单位是纳秒ns，1ms等于10的6次方纳秒ns*/
        pulse = 0;          /* PWM脉冲宽度值，单位为纳秒ns */
        dir = 1;
        /* 查找设备 */
        pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);
        if (pwm_dev == RT_NULL)
             {
    
                 rt_kprintf("pwm sample run failed! can't find %s device!\n", PWM_DEV_NAME);
             }
            rt_kprintf("pwm sample run ! find %s device!\n", PWM_DEV_NAME);
        /* 设置PWM周期和脉冲宽度 */
        rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
        /* 使能设备 */
        rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);

        while (1)
            {
    
                rt_thread_mdelay(50);
                if (dir)
                {
    
                    pulse += 20000;      /* 从0值开始每次增加20000ns */
                }
                else
                {
    
                    pulse -= 20000;      /* 从最大值开始每次减少20000ns */
                }
                if (pulse >= period)
                {
    
                    dir = 0;
//                    rt_kprintf("pwm sample change direction! to --\n");
                }
                if (0 == pulse)
                {
    
                    dir = 1;
//                    rt_kprintf("pwm sample change direction to ++ !\n");
                }

                /* 设置PWM周期和脉冲宽度并启动 */
                rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
                rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);
            }
}

int main(void)
{
    

    MX_TIM8_Init();

    pwm_tid = rt_thread_create("pwm_thread",
                                    pwm_thread_entry, RT_NULL,
                                    THREAD_STACK_SIZE,
                                    THREAD_PRIORITY, THREAD_TIMESLICE);

            /* 如果获得线程控制块，启动这个线程 */
            if (pwm_tid != RT_NULL)
                {
    
                    //启动线程1
                    rt_thread_startup(pwm_tid);
                    LOG_D("pwm_thread created successful");
                }
            else {
    
                    LOG_D("pwm_thread created failed");
                    }

    return RT_EOK;
}



#include "stm32h7xx.h"
static int vtor_config(void)
{
    
    /* Vector Table Relocation in Internal QSPI_FLASH */
    SCB->VTOR = QSPI_BASE;
    return 0;
}
INIT_BOARD_EXPORT(vtor_config);

如果项目开启了finsh，可以通过list_device查看到pwm8这个设备，如下图所示。

6. 避坑指南

前面说我们创建的是基于ART-Pi开发板的模板工程，那么是有一个需要修改的地方，这一点在目前任何网上一个教程都没有提到。默认情况下，ART-Pi开发板模板工程默认是将libraries\drivers\drv_pwm.c排除在构建之外的，需要修改libraries\drivers\SConscript文件，添加drv_pwm.c文件，才能正确配置pwm设备。如下图。