问题描述
目前我正在尝试操作 WS2811 LED 灯带。我看到它的方式是使用 STM32 MC（我有 nucleo-f303k8）通过 DMA 传输脉冲值，因此定时器在 STM 引脚上创建连续的 PWM 信号，WS2811 获得 gata 并以正确的颜色点亮正确的 LED。
但是，现在我在 DMA 方面遇到了一个大问题：使用 CubeMX 和 Keil Uvision，我在 CubeMX 的默认设置（仅配置预分频器、计数器和脉冲）的计时器上配置了 DMA。使用 hal_tim_pwm_start_dma 函数并没有给我我需要的结果：无论我在函数中使用的变量中输入什么值，它都会在 100% 的周期内为我提供 3.3V 信号。谷歌搜索让我找到了 0 个相同的问题。
这是来自 main.c 的代码。其他文件中的所有内容都保持不变。
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define DATA_LENGTH 6
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim2;
DMA_HandleTypeDef hdma_tim2_ch2_ch4;
UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
uint32_t ws2811_data [DATA_LENGTH] = {6,1,3,17,9};
/* 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_USART2_UART_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_USART2_UART_Init();
MX_TIM2_Init();
/* USER CODE BEGIN 2 */
//TIM2->EGR |= TIM_EGR_UG;
//TIM2->CCR2 = ws2811_data[0];
//HAL_TIM_PWM_Start(&htim2,TIM_CHANNEL_2);
HAL_TIM_PWM_Start_DMA(&htim2,TIM_CHANNEL_2,ws2811_data,DATA_LENGTH);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* 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_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
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_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct,FLASH_LATENCY_0) != 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 */
TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};
/* USER CODE END TIM2_Init 1 */
htim2.Instance = TIM2;
htim2.Init.Prescaler = 79;
htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
htim2.Init.Period = 20;
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_ENABLE;
if (HAL_TIM_PWM_ConfigChannel(&htim2,&sConfigOC,TIM_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
__HAL_TIM_disABLE_OCxPRELOAD(&htim2,TIM_CHANNEL_2);
/* USER CODE BEGIN TIM2_Init 2 */
htim2.Init.RepetitionCounter = 1;
sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
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.AutomaticOutput = TIM_AUTOMATICOUTPUT_disABLE;
if (HAL_TIMEx_ConfigBreakDeadTime(&htim2,&sBreakDeadTimeConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE END TIM2_Init 2 */
HAL_TIM_MspPostinit(&htim2);
}
/**
* @brief USART2 Initialization Function
* @param None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.Baudrate = 38400;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_disABLE;
huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_Init 2 */
}
/**
* Enable DMA controller clock
*/
static void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Channel7_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel7_IRQn,0);
HAL_NVIC_EnableIRQ(DMA1_Channel7_IRQn);
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOF_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_Failed(uint8_t *file,uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,ex: printf("Wrong parameters value: file %s on line %d\r\n",file,line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
/************************ (C) copYRIGHT STMicroelectronics *****END OF FILE****/
解决方法
所以问题出在计时器上。我试图让我的程序运行，使用 TIM2，但输出看起来不像我想要的任何东西。然后我决定切换到 TIM1，出于某种神奇的原因，一切都开始工作了！
也就是说，如果您遇到同样的问题，请尝试在 STM32 的定时器之间切换。