求助一个基于HAL库的PWM+DMA的例程代码，一直弄不出来啊。....

int main(void)

{

  /* USER CODE BEGIN 1 */

        uint16_t i;

  /* USER CODE END 1 */

  



  /* MCU Configuration--------------------------------------------------------*/



  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */

  HAL_Init();



  /* USER CODE BEGIN Init */



  /* USER CODE END Init */



  /* Configure the system clock */

  SystemClock_Config();



  /* USER CODE BEGIN SysInit */



  /* USER CODE END SysInit */



  /* Initialize all configured peripherals */

  MX_GPIO_Init();

  MX_TIM3_Init();

  MX_DMA_Init();

  /* USER CODE BEGIN 2 */

        

        for(i = 0; i < SEND_SIZE; i++)

        {

                pwm_buf[i] = 200;

        }

  /* USER CODE END 2 */



  /* Infinite loop */

  /* USER CODE BEGIN WHILE */

  while (1)

  {

    /* USER CODE END WHILE */



    /* USER CODE BEGIN 3 */

                

                HAL_TIM_PWM_Start_DMA(&htim3, TIM_CHANNEL_3, (uint32_t *)(&(pwm_buf[0])), SEND_SIZE*2);

                HAL_Delay(200);

  }

  /* USER CODE END 3 */

}

static void MX_TIM3_Init(void)

{



  /* USER CODE BEGIN TIM3_Init 0 */



  /* USER CODE END TIM3_Init 0 */



  TIM_ClockConfigTypeDef sClockSourceConfig = {0};

  TIM_MasterConfigTypeDef sMasterConfig = {0};

  TIM_OC_InitTypeDef sConfigOC = {0};



  /* USER CODE BEGIN TIM3_Init 1 */



  /* USER CODE END TIM3_Init 1 */

  htim3.Instance = TIM3;

  htim3.Init.Prescaler = 0;

  htim3.Init.CounterMode = TIM_COUNTERMODE_UP;

  htim3.Init.Period = 10000;

  htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;

  htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;

  if (HAL_TIM_Base_Init(&htim3) != HAL_OK)

  {

    Error_Handler();

  }

  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;

  if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)

  {

    Error_Handler();

  }

  if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)

  {

    Error_Handler();

  }

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;

  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;

  if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)

  {

    Error_Handler();

  }

  sConfigOC.OCMode = TIM_OCMODE_PWM1;

  sConfigOC.Pulse = 0;

  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;

  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;

  if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)

  {

    Error_Handler();

  }

  __HAL_TIM_DISABLE_OCxPRELOAD(&htim3, TIM_CHANNEL_3);

  /* USER CODE BEGIN TIM3_Init 2 */



  /* USER CODE END TIM3_Init 2 */

  HAL_TIM_MspPostInit(&htim3);



}

static void MX_DMA_Init(void) 

{



  /* DMA controller clock enable */

  __HAL_RCC_DMA1_CLK_ENABLE();



  /* DMA interrupt init */

  /* DMA1_Channel2_3_IRQn interrupt configuration */

  HAL_NVIC_SetPriority(DMA1_Channel2_3_IRQn, 0, 0);

  HAL_NVIC_EnableIRQ(DMA1_Channel2_3_IRQn);



}

static void MX_GPIO_Init(void)

{



  /* GPIO Ports Clock Enable */

  __HAL_RCC_GPIOB_CLK_ENABLE();



}

void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* htim_base)

{

  if(htim_base->Instance==TIM3)

  {

  /* USER CODE BEGIN TIM3_MspInit 0 */



  /* USER CODE END TIM3_MspInit 0 */

    /* Peripheral clock enable */

    __HAL_RCC_TIM3_CLK_ENABLE();

  

    /* TIM3 DMA Init */

    /* TIM3_CH3 Init */

    hdma_tim3_ch3.Instance = DMA1_Channel2;

    hdma_tim3_ch3.Init.Direction = DMA_MEMORY_TO_PERIPH;

    hdma_tim3_ch3.Init.PeriphInc = DMA_PINC_DISABLE;

    hdma_tim3_ch3.Init.MemInc = DMA_MINC_ENABLE;

    hdma_tim3_ch3.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;

    hdma_tim3_ch3.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;

    hdma_tim3_ch3.Init.Mode = DMA_CIRCULAR;

    hdma_tim3_ch3.Init.Priority = DMA_PRIORITY_VERY_HIGH;

    if (HAL_DMA_Init(&hdma_tim3_ch3) != HAL_OK)

    {

      Error_Handler();

    }



    __HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_CC3],hdma_tim3_ch3);



  /* USER CODE BEGIN TIM3_MspInit 1 */



  /* USER CODE END TIM3_MspInit 1 */

  }



}

void HAL_TIM_MspPostInit(TIM_HandleTypeDef* htim)

{

  GPIO_InitTypeDef GPIO_InitStruct = {0};

  if(htim->Instance==TIM3)

  {

  /* USER CODE BEGIN TIM3_MspPostInit 0 */



  /* USER CODE END TIM3_MspPostInit 0 */

  

    __HAL_RCC_GPIOB_CLK_ENABLE();

    /**TIM3 GPIO Configuration    

    PB0     ------> TIM3_CH3 

    */

    GPIO_InitStruct.Pin = GPIO_PIN_0;

    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

    GPIO_InitStruct.Pull = GPIO_NOPULL;

    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;

    GPIO_InitStruct.Alternate = GPIO_AF1_TIM3;

    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);



  /* USER CODE BEGIN TIM3_MspPostInit 1 */



  /* USER CODE END TIM3_MspPostInit 1 */

  }



}