STM32CUBEIDE FreeRTOS操作教程（九）：eventgroup事件标志组

STM32CUBEIDE FreeRTOS操作教程（九）：eventgroup事件标志组

STM32CUBE开发环境集成了STM32 HAL库进行FreeRTOS配置和开发的组件，不需要用户自己进行FreeRTOS的移植。这里介绍最简化的用户操作类应用教程。以STM32F401RCT6开发板为例，只用到USB，USART1极少的接口，体现FreeRTOS的各种操作过程。

操作教程（九）配置FreeRTOS及相关环境，实现LED闪灯功能及基于eventgroup事件标志组的USB虚拟串口发收环回。从电脑端连接USB虚拟串口后，发送出去的串口数据，会被保存且一个事件标志位被设置，在任务中发现该事件标志位有效，则将数据通过USB虚拟串口返回电脑端。本例程也设置了一个timer软件定时器，定时设置一个事件标志位，任务发现定时器设置的事件标志位有效，通过虚拟串口向外打印出固定信息。

FreeRTOS的教程较多，推荐参考正点原子所出的《STM32F407 FreeRTOS开发手册》了解相关知识。

STM32CUBEIDE工程配置

选择TIM1(也可以是其它TIM)作为FreeRTOS操作系统占用的时钟源：

配置时钟树包括USB的48MHz时钟：

配置PC13为低电平点灯的管脚：

配置USB串口:

配置UART1串口（但本例中不用到UART1):

FreeRTOS配置

、

保存并生成基础工程代码：

在生成代码的这个部分可以看到FreeRTOS代码部分：

任务实现

基于前述的配置，main.c代码里会加载Free-RTOS的配置，并启动几个任务的调度，当然，此时的任务都是什么也不干。实现LED闪灯，就在LED闪灯任务里加入代码即可：

void StartTask_TASK_LED_FLASH(void *argument)
{
  /* USER CODE BEGIN StartTask_TASK_LED_FLASH */
  /* Infinite loop */
  for(;;)
  {
    osDelay(1000);
    HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_13);
  }
  /* USER CODE END StartTask_TASK_LED_FLASH */
}

也就实现了LED闪灯功能，其中osDelay(1000);实现1秒时间的操作系统调度延时，也就是1秒执行一次LED灯的亮灭。osDelay(1）；是最小的调度延时，为1毫秒。要实现更小的延时，则可以用微秒延时函数实现，参考《STM32 HAL us delay（微秒延时）的指令延时实现方式及优化》。

在USB的接收中断里，保存接收到的数据和数据长度，并设置事件标志位：

static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
{
  /* USER CODE BEGIN 6 */
	extern uint8_t USB_VCOM_BUFF[1024];
	extern uint32_t USB_VCOM_INDEX;

	extern osEventFlagsId_t USB_VCOM_Event01Handle;
	extern BaseType_t USB_VCOM_pxHigherPriorityTaskWaken;

	memcpy(USB_VCOM_BUFF, Buf, *Len);
	USB_VCOM_INDEX = *Len;

	xEventGroupSetBitsFromISR( USB_VCOM_Event01Handle, 0x01, USB_VCOM_pxHigherPriorityTaskWaken);


  USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
  USBD_CDC_ReceivePacket(&hUsbDeviceFS);
  return (USBD_OK);
  /* USER CODE END 6 */
}

main.c文件里软件定时器设置事件标志位：

void USB_VCOM_Timer01_Callback01(void *argument)
{
  /* USER CODE BEGIN USB_VCOM_Timer01_Callback01 */

	xEventGroupSetBitsFromISR( USB_VCOM_Event01Handle, 0x02, USB_VCOM_pxHigherPriorityTaskWaken);

  /* USER CODE END USB_VCOM_Timer01_Callback01 */
}

main.c文件里任务处理：

void StartTask_TASK_USB_VCOM(void *argument)
{
  /* USER CODE BEGIN StartTask_TASK_USB_VCOM */
   EventBits_t Flags = 0;
  /* Infinite loop */
  for(;;)
  {
    osDelay(10);
    Flags = xEventGroupGetBits( USB_VCOM_Event01Handle );
    if(Flags&0x01)
    {
    	usbprintarray(USB_VCOM_BUFF, USB_VCOM_INDEX);
    	xEventGroupClearBits( USB_VCOM_Event01Handle, 0x01);
    }

    if(Flags&0x02)
    {
    	usbprintstring("\r\nSoftware Timer Outputs\r\n");
    	xEventGroupClearBits( USB_VCOM_Event01Handle, 0x02);
    }


  }
  /* USER CODE END StartTask_TASK_USB_VCOM */
}

完整的main.c文件：

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2023 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
//Example 9: LED flash + USB VCOM loop back with event-group & timer
//Written by Pegasus Yu
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "cmsis_os.h"
#include "usb_device.h"

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

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
__IO float usDelayBase = 7.63238716; //For STM32F401RCT6 working in 84MHz main clock

void PY_Delay_us_t(uint32_t Delay)
{
  __IO uint32_t delayReg;
  __IO uint32_t usNum = (uint32_t)(Delay*usDelayBase);

  delayReg = 0;
  while(delayReg!=usNum) delayReg++;
}
/* 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 ---------------------------------------------------------*/
UART_HandleTypeDef huart1;
DMA_HandleTypeDef hdma_usart1_rx;

/* Definitions for defaultTask */
osThreadId_t defaultTaskHandle;
const osThreadAttr_t defaultTask_attributes = {
  .name = "defaultTask",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityNormal,
};
/* Definitions for TASK_LED_FLASH */
osThreadId_t TASK_LED_FLASHHandle;
const osThreadAttr_t TASK_LED_FLASH_attributes = {
  .name = "TASK_LED_FLASH",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityLow,
};
/* Definitions for TASK_UART1 */
osThreadId_t TASK_UART1Handle;
const osThreadAttr_t TASK_UART1_attributes = {
  .name = "TASK_UART1",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityLow,
};
/* Definitions for TASK_USB_VCOM */
osThreadId_t TASK_USB_VCOMHandle;
const osThreadAttr_t TASK_USB_VCOM_attributes = {
  .name = "TASK_USB_VCOM",
  .stack_size = 128 * 4,
  .priority = (osPriority_t) osPriorityLow,
};
/* Definitions for USB_VCOM_Timer01 */
osTimerId_t USB_VCOM_Timer01Handle;
const osTimerAttr_t USB_VCOM_Timer01_attributes = {
  .name = "USB_VCOM_Timer01"
};
/* Definitions for USB_VCOM_Event01 */
osEventFlagsId_t USB_VCOM_Event01Handle;
const osEventFlagsAttr_t USB_VCOM_Event01_attributes = {
  .name = "USB_VCOM_Event01"
};
/* USER CODE BEGIN PV */

/* 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_USART1_UART_Init(void);
void StartDefaultTask(void *argument);
void StartTask_TASK_LED_FLASH(void *argument);
void StartTask_TASK_UART1(void *argument);
void StartTask_TASK_USB_VCOM(void *argument);
void USB_VCOM_Timer01_Callback01(void *argument);

/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t CDC_Transmit_FS(uint8_t* Buf, uint16_t Len);
void usbprintstring(char * data)
{
	if(CDC_Transmit_FS((uint8_t *)data, strlen(data))==USBD_BUSY)
	{
		PY_Delay_us_t(1000000);
	    CDC_Transmit_FS((uint8_t *)data, strlen(data));
	}
}

void usbprintarray(uint8_t * data, uint16_t len)
{
	if(CDC_Transmit_FS(data, len)==USBD_BUSY)
	{
		PY_Delay_us_t(1000000);
		CDC_Transmit_FS(data, len);
	}
}

uint8_t USB_VCOM_BUFF[1024];
uint32_t USB_VCOM_INDEX = 0;

BaseType_t USB_VCOM_pxHigherPriorityTaskWaken = 0;
TickType_t USB_VCOM_xBlockTime = 0;
uint32_t Timer_Period_ms = 10;
/* 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_USART1_UART_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Init scheduler */
  osKernelInitialize();

  /* USER CODE BEGIN RTOS_MUTEX */
  /* add mutexes, ... */
  /* USER CODE END RTOS_MUTEX */

  /* USER CODE BEGIN RTOS_SEMAPHORES */
  /* add semaphores, ... */
  /* USER CODE END RTOS_SEMAPHORES */

  /* Create the timer(s) */
  /* creation of USB_VCOM_Timer01 */
  USB_VCOM_Timer01Handle = osTimerNew(USB_VCOM_Timer01_Callback01, osTimerPeriodic, NULL, &USB_VCOM_Timer01_attributes);

  /* USER CODE BEGIN RTOS_TIMERS */
  /* start timers, add new ones, ... */
  /* USER CODE END RTOS_TIMERS */

  /* USER CODE BEGIN RTOS_QUEUES */
  /* add queues, ... */
  /* USER CODE END RTOS_QUEUES */

  /* Create the thread(s) */
  /* creation of defaultTask */
  defaultTaskHandle = osThreadNew(StartDefaultTask, NULL, &defaultTask_attributes);

  /* creation of TASK_LED_FLASH */
  TASK_LED_FLASHHandle = osThreadNew(StartTask_TASK_LED_FLASH, NULL, &TASK_LED_FLASH_attributes);

  /* creation of TASK_UART1 */
  TASK_UART1Handle = osThreadNew(StartTask_TASK_UART1, NULL, &TASK_UART1_attributes);

  /* creation of TASK_USB_VCOM */
  TASK_USB_VCOMHandle = osThreadNew(StartTask_TASK_USB_VCOM, NULL, &TASK_USB_VCOM_attributes);

  /* USER CODE BEGIN RTOS_THREADS */
  /* add threads, ... */
  /* USER CODE END RTOS_THREADS */

  /* Create the event(s) */
  /* creation of USB_VCOM_Event01 */
  USB_VCOM_Event01Handle = osEventFlagsNew(&USB_VCOM_Event01_attributes);

  /* USER CODE BEGIN RTOS_EVENTS */
  /* add events, ... */
  /* USER CODE END RTOS_EVENTS */

  /* Start scheduler */
  osKernelStart();

  /* We should never get here as control is now taken by the scheduler */

  /* 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};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);

  /** 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.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 25;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  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 USART1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART1_UART_Init(void)
{

  /* USER CODE BEGIN USART1_Init 0 */

  /* USER CODE END USART1_Init 0 */

  /* USER CODE BEGIN USART1_Init 1 */

  /* USER CODE END USART1_Init 1 */
  huart1.Instance = USART1;
  huart1.Init.BaudRate = 115200;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART1_Init 2 */

  /* USER CODE END USART1_Init 2 */

}

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

  /* DMA controller clock enable */
  __HAL_RCC_DMA2_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA2_Stream2_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 5, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LED_GPIO_Port, LED_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : LED_Pin */
  GPIO_InitStruct.Pin = LED_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(LED_GPIO_Port, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/* USER CODE BEGIN Header_StartDefaultTask */
/**
  * @brief  Function implementing the defaultTask thread.
  * @param  argument: Not used
  * @retval None
  */
/* USER CODE END Header_StartDefaultTask */
void StartDefaultTask(void *argument)
{
  /* init code for USB_DEVICE */
  MX_USB_DEVICE_Init();
  /* USER CODE BEGIN 5 */
    Timer_Period_ms = 2000;
	xTimerChangePeriodFromISR( USB_VCOM_Timer01Handle, Timer_Period_ms, &USB_VCOM_pxHigherPriorityTaskWaken );
	xTimerStartFromISR( USB_VCOM_Timer01Handle, &USB_VCOM_pxHigherPriorityTaskWaken );  //Start Timer
  /* Infinite loop */
  for(;;)
  {
    osDelay(1);
  }
  /* USER CODE END 5 */
}

/* USER CODE BEGIN Header_StartTask_TASK_LED_FLASH */
/**
* @brief Function implementing the TASK_LED_FLASH thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_StartTask_TASK_LED_FLASH */
void StartTask_TASK_LED_FLASH(void *argument)
{
  /* USER CODE BEGIN StartTask_TASK_LED_FLASH */
  /* Infinite loop */
  for(;;)
  {
    osDelay(1000);
    HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_13);
  }
  /* USER CODE END StartTask_TASK_LED_FLASH */
}

/* USER CODE BEGIN Header_StartTask_TASK_UART1 */
/**
* @brief Function implementing the TASK_UART1 thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_StartTask_TASK_UART1 */
void StartTask_TASK_UART1(void *argument)
{
  /* USER CODE BEGIN StartTask_TASK_UART1 */
  /* Infinite loop */
  for(;;)
  {
    osDelay(1);
  }
  /* USER CODE END StartTask_TASK_UART1 */
}

/* USER CODE BEGIN Header_StartTask_TASK_USB_VCOM */
/**
* @brief Function implementing the TASK_USB_VCOM thread.
* @param argument: Not used
* @retval None
*/
/* USER CODE END Header_StartTask_TASK_USB_VCOM */
void StartTask_TASK_USB_VCOM(void *argument)
{
  /* USER CODE BEGIN StartTask_TASK_USB_VCOM */
   EventBits_t Flags = 0;
  /* Infinite loop */
  for(;;)
  {
    osDelay(10);
    Flags = xEventGroupGetBits( USB_VCOM_Event01Handle );
    if(Flags&0x01)
    {
    	usbprintarray(USB_VCOM_BUFF, USB_VCOM_INDEX);
    	xEventGroupClearBits( USB_VCOM_Event01Handle, 0x01);
    }

    if(Flags&0x02)
    {
    	usbprintstring("\r\nSoftware Timer Outputs\r\n");
    	xEventGroupClearBits( USB_VCOM_Event01Handle, 0x02);
    }


  }
  /* USER CODE END StartTask_TASK_USB_VCOM */
}

/* USB_VCOM_Timer01_Callback01 function */
void USB_VCOM_Timer01_Callback01(void *argument)
{
  /* USER CODE BEGIN USB_VCOM_Timer01_Callback01 */

	xEventGroupSetBitsFromISR( USB_VCOM_Event01Handle, 0x02, USB_VCOM_pxHigherPriorityTaskWaken);

  /* USER CODE END USB_VCOM_Timer01_Callback01 */
}

/**
  * @brief  Period elapsed callback in non blocking mode
  * @note   This function is called  when TIM1 interrupt took place, inside
  * HAL_TIM_IRQHandler(). It makes a direct call to HAL_IncTick() to increment
  * a global variable "uwTick" used as application time base.
  * @param  htim : TIM handle
  * @retval None
  */
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
  /* USER CODE BEGIN Callback 0 */

  /* USER CODE END Callback 0 */
  if (htim->Instance == TIM1) {
    HAL_IncTick();
  }
  /* USER CODE BEGIN Callback 1 */

  /* USER CODE END Callback 1 */
}

/**
  * @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 */

例程下载

STM32 STM32CUBEIDE FreeRTOS操作教程（九）：eventgroup事件标志组 例程

例程测试

例程测试效果如下：

--End--