STM32F103 PWM 带定时器和 DMA 用于 WS2812 中断功能不断调用

Question

我正在尝试使用定时器生成的 PWM 和用于节省内存的循环 DMA 缓冲区为 WS2812 LED 制作自己的驱动程序。 我设法获得了正确的时序，但是，使用逻辑分析仪查看信号时，我注意到两个主要问题：

• 例如，当应该发送 72 位时，只发送 27 位。
• 即使在有限的 27 位中，也发送了错误的数据并且没有以适当的顺序发送。

这是否真的与不断被调用的中断有关，我不完全确定。 我猜这是问题所在，因为没有发送全部位，我还尝试在任一中断上切换 GPIO 引脚，结果是该引脚始终保持关闭状态，可能表明该中断被连续调用所以引脚没有足够的时间打开。 我不确定是否有任何其他方法可以测试中断发生的时间和时间间隔。

如果这确实是连续调用中断的情况，那可能是什么问题？ 据我所知，我正在使用适当的回调函数，并且我的初始化是有序的。 然而，我发现奇怪的部分是，每当我注释掉 DMA PWM 停止函数时，它就会开始正确地发送位，即正确的数量和正确的顺序。 如果连续调用中断，我认为这不会起作用，因为 DMA 缓冲区会不断被中断例程更改，这会导致错误输出。 我会感谢任何提示或建议！ 这是代码：

主程序

#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "ws2812.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
 TIM_HandleTypeDef htim2;
DMA_HandleTypeDef hdma_tim2_ch1;

/* USER CODE BEGIN PV */
uint8_t fbuffer[NUM_LEDS*3];
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_TIM2_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */
  /* 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_DMA_Init();
  MX_TIM2_Init();
  /* USER CODE BEGIN 2 */
//  if(sbyte & (1 << 7)) lh = 65;
//  else lh = 25;
  fbuffer[0] = 255;
  fbuffer[1] = 0;
  fbuffer[2] = 0;
  fbuffer[3] = 0;
  fbuffer[4] = 0;
  fbuffer[5] = 0;
  fbuffer[6] = 0;
  fbuffer[7] = 255;
  fbuffer[8] = 0;
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    ws2812_show(fbuffer);
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief TIM2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_TIM2_Init(void)
{

  /* USER CODE BEGIN TIM2_Init 0 */

  /* USER CODE END TIM2_Init 0 */

  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};

  /* USER CODE BEGIN TIM2_Init 1 */

  /* USER CODE END TIM2_Init 1 */
  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 0;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 89;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
  if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_PWM_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &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(&htim2, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN TIM2_Init 2 */

  /* USER CODE END TIM2_Init 2 */
  HAL_TIM_MspPostInit(&htim2);

}

/**
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void)
{

  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA1_Channel5_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Channel5_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Channel5_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_RESET);

  /*Configure GPIO pin : PA0 */
  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

}

ws2812.c

#include "main.h"
#include "ws2812.h"

extern TIM_HandleTypeDef htim2;
extern DMA_HandleTypeDef hdma_tim2_ch1;
extern uint8_t fbuffer[NUM_LEDS*3];

uint16_t indby = 3;
uint32_t bcolors = 0;
uint8_t circbuffer[24] = {0};

uint8_t rd_flag = 0;
uint8_t in_flag = 0;

// Interrupt for when half of the DMA buffer is reached.
void HAL_TIM_PWM_PulseFinishedHalfCpltCallback(TIM_HandleTypeDef *htim)
{
    if (htim->Instance == htim2.Instance) {
        if(indby < NUM_LEDS*3) {
            // Fill the first half of the DMA buffer
            bcolors = (fbuffer[indby+1] << 16) | (fbuffer[indby] << 8) | fbuffer[indby+2];
            for(uint8_t i = 23; i > 11; i--) {
                if(bcolors & (1<<i)) circbuffer[23-i] = HT;
                else circbuffer[23-i] = LT;
            }
        }
    }
}

// Interrupt for when all of the DMA buffer is passed.
void HAL_TIM_PWM_PulseFinishedCallback(TIM_HandleTypeDef *htim)
{
    if (htim->Instance == htim2.Instance) {
        if(indby < NUM_LEDS*3) {
            // Set the latter half of the DMA buffer
            for(uint8_t i = 11; i > 0; i--) {
                if(bcolors & (1<<i)) circbuffer[23-i] = HT;
                else circbuffer[23-i] = LT;
            }
            if(bcolors & (1<<0)) circbuffer[23] = HT;
            else circbuffer[23] = LT;
            indby += 3;
            //HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_0);
        }
        // Stop PWM if last LED bit reached.
        else {
            HAL_TIM_PWM_Stop_DMA(&htim2, TIM_CHANNEL_1);
            rd_flag = 0;
        }
    }
}

uint8_t ws2812_show(uint8_t fbuffer[])
{
    // State machine like switch to make sure the functions runs properly on
    // consecutive calls
    switch(0 ^ in_flag ^ (rd_flag<<1)) {
    // Initialization state
    case 0:
        in_flag = 1;
        rd_flag = 1;
        bcolors = (fbuffer[1] << 16) | (fbuffer[0] << 8) | fbuffer[2];
        for(uint8_t i = 23; i > 0; i--) {
            if(bcolors & (1<<i)) circbuffer[23-i] = HT;
            else circbuffer[23-i] = LT;
        }
        if(bcolors & (1<<0)) circbuffer[23] = HT;
        else circbuffer[23] = LT;
        HAL_TIM_PWM_Start_DMA(&htim2, TIM_CHANNEL_1, (uint32_t *)circbuffer, 24);
        return 0;
        break;
    // Running state
    case 3:
        return 0;
        break;
    // Finished state
    case 1:
        in_flag = 0;
        return 1;
        break;
    // Something is up state
    case 2:
        rd_flag = 0;
        return 0;
        break;
    default:
        return 0;
    }
}

stm32f1xx_hal_msp.c

#include "main.h"
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */
extern DMA_HandleTypeDef hdma_tim2_ch1;

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD */

/* USER CODE END TD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN Define */

/* USER CODE END Define */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN Macro */

/* USER CODE END Macro */

/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* External functions --------------------------------------------------------*/
/* USER CODE BEGIN ExternalFunctions */

/* USER CODE END ExternalFunctions */

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

void HAL_TIM_MspPostInit(TIM_HandleTypeDef *htim);
                    /**
  * Initializes the Global MSP.
  */
void HAL_MspInit(void)
{
  /* USER CODE BEGIN MspInit 0 */

  /* USER CODE END MspInit 0 */

  __HAL_RCC_AFIO_CLK_ENABLE();
  __HAL_RCC_PWR_CLK_ENABLE();

  /* System interrupt init*/

  /** NOJTAG: JTAG-DP Disabled and SW-DP Enabled
  */
  __HAL_AFIO_REMAP_SWJ_NOJTAG();

  /* USER CODE BEGIN MspInit 1 */

  /* USER CODE END MspInit 1 */
}

/**
* @brief TIM_Base MSP Initialization
* This function configures the hardware resources used in this example
* @param htim_base: TIM_Base handle pointer
* @retval None
*/
void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* htim_base)
{
  if(htim_base->Instance==TIM2)
  {
  /* USER CODE BEGIN TIM2_MspInit 0 */

  /* USER CODE END TIM2_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_TIM2_CLK_ENABLE();

    /* TIM2 DMA Init */
    /* TIM2_CH1 Init */
    hdma_tim2_ch1.Instance = DMA1_Channel5;
    hdma_tim2_ch1.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_tim2_ch1.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_tim2_ch1.Init.MemInc = DMA_MINC_ENABLE;
    hdma_tim2_ch1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
    hdma_tim2_ch1.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_tim2_ch1.Init.Mode = DMA_CIRCULAR;
    hdma_tim2_ch1.Init.Priority = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_tim2_ch1) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_CC1],hdma_tim2_ch1);

    /* TIM2 interrupt Init */
    HAL_NVIC_SetPriority(TIM2_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(TIM2_IRQn);
  /* USER CODE BEGIN TIM2_MspInit 1 */

  /* USER CODE END TIM2_MspInit 1 */
  }

}

void HAL_TIM_MspPostInit(TIM_HandleTypeDef* htim)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(htim->Instance==TIM2)
  {
  /* USER CODE BEGIN TIM2_MspPostInit 0 */

  /* USER CODE END TIM2_MspPostInit 0 */

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**TIM2 GPIO Configuration
    PA15     ------> TIM2_CH1
    */
    GPIO_InitStruct.Pin = GPIO_PIN_15;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    __HAL_AFIO_REMAP_TIM2_PARTIAL_1();

  /* USER CODE BEGIN TIM2_MspPostInit 1 */

  /* USER CODE END TIM2_MspPostInit 1 */
  }

}
/**
* @brief TIM_Base MSP De-Initialization
* This function freeze the hardware resources used in this example
* @param htim_base: TIM_Base handle pointer
* @retval None
*/
void HAL_TIM_Base_MspDeInit(TIM_HandleTypeDef* htim_base)
{
  if(htim_base->Instance==TIM2)
  {
  /* USER CODE BEGIN TIM2_MspDeInit 0 */

  /* USER CODE END TIM2_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_TIM2_CLK_DISABLE();

    /* TIM2 DMA DeInit */
    HAL_DMA_DeInit(htim_base->hdma[TIM_DMA_ID_CC1]);

    /* TIM2 interrupt DeInit */
    HAL_NVIC_DisableIRQ(TIM2_IRQn);
  /* USER CODE BEGIN TIM2_MspDeInit 1 */

  /* USER CODE END TIM2_MspDeInit 1 */
  }

}

如果需要，我可以稍后提供逻辑分析仪波形。

Answer 1

字面上忘记了简单地重置字节计数变量indby 。 以此为教训，非常仔细地检查您的代码！