当前位置：首页 > news >正文

Freertos手把手教STM32CubeMx设置STM32F4芯片DMA发送ADC数据（四）

news 2026/7/5 22:47:43

前置文章：

Freertos手把手教STM32CubeMx设置STM32F4芯片DMA发送ADC数据（一）-CSDN博客Freertos手把手教STM32CubeMx设置STM32F4芯片DMA发送ADC数据（二）-CSDN博客

Freertos手把手教STM32CubeMx设置STM32F4芯片DMA发送ADC数据（三）-CSDN博客

在以上章节完成了对框架的初步探索以及对CubeMx的配置

在freertos的task中对buffer进行了一些测试

完成了队列的发送接收测试以及对ADC触发的中断函数进行了编写

下面继续上一章的内容继续完成本次目标

本期目标

理清本工程系统框架

弄懂CubeMx配置相关原理及设置的背后含义

对DMA以及ADC相关的重要API接口使用详解

梳理代码设计流程

xQueueSendFromISR（）

当你在中断里面发送这个函数的时候，如果有优先级更高的队列接收任务，正在等待队列唤醒，他会在发送队列的过程中立马切换任务，去执行优先级更高的任务，以保证系统的实时性

对于立刻切换的这个动作，一定会使用PendSV中断，但是这个中断在任何时候优先级都是最低的，所以就不可能在我们当前这个DMA里面去中断

所以在这里用这个函数会被卡死

ret_queue = xQueueSend( xQueue1, &dma_pattern_cplt, 0 );

而xQueueSendFromISR这个函数相较于xQueueSend ，在任务切换时做了一个延迟的动作

xHigherPriorityTaskWoken

在发送过程中，这个函数（xQueueSendFromISR）如果发现有更高优先级的任务要切换，它将会把xHigherPriorityTaskWoken置为true

如果xHigherPriorityTaskWoken置为true了，系统就会暂时先把PendSV置位，等退出了当前中断函数，并且比PendSV更高优先级的中断都结束了，再去执行PendSV

if( xHigherPriorityTaskWoken ) { taskYIELD (); }

就是这个taskYIELD ，其原理就是会在这里进行一个悬起，在离开这个中断之后就会立即响应此悬起，从而完成任务切换

注意：

xQueue1 = xQueueCreate(10 , 4 ); if(NULL == xQueue1) { printf("Queue create failed \r\n"); return ; }

创建队列的代码要放在ADC启动前，ADC一启动，中断立马就产生，但是队列还没创建，会出问题

/* Includes ------------------------------------------------------------------*/ #include "FreeRTOS.h" #include "task.h" #include "main.h" #include "cmsis_os.h" /* Private includes ----------------------------------------------------------*/ /* USER CODE BEGIN Includes */ #include <stdlib.h> #include "queue.h" /* USER CODE END Includes */ /* Private typedef -----------------------------------------------------------*/ /* USER CODE BEGIN PTD */ #define BUFFER_SIZE 1 uint32_t * buffer1 = NULL; uint32_t * buffer2 = NULL; /* USER CODE END PTD */ /* Private define ------------------------------------------------------------*/ /* USER CODE BEGIN PD */ /* USER CODE END PD */ /* Private macro -------------------------------------------------------------*/ /* USER CODE BEGIN PM */ #define DMA_ADC_CPLT_INT 0xA1A1A1A1 /* USER CODE END PM */ /* Private variables ---------------------------------------------------------*/ /* USER CODE BEGIN Variables */ extern ADC_HandleTypeDef hadc1; extern DMA_HandleTypeDef hdma_adc1; QueueHandle_t xQueue1 = NULL; /* USER CODE END Variables */ /* Definitions for defaultTask */ osThreadId_t defaultTaskHandle; const osThreadAttr_t defaultTask_attributes = { .name = "defaultTask", .stack_size = 128 * 4, .priority = (osPriority_t) osPriorityNormal, }; /* Private function prototypes -----------------------------------------------*/ /* USER CODE BEGIN FunctionPrototypes */ /* USER CODE END FunctionPrototypes */ void StartDefaultTask(void *argument); void MX_FREERTOS_Init(void); /* (MISRA C 2004 rule 8.1) */ /** * @brief FreeRTOS initialization * @param None * @retval None */ void MX_FREERTOS_Init(void) { /* USER CODE BEGIN Init */ /* USER CODE END Init */ /* USER CODE BEGIN RTOS_MUTEX */ /* add mutexes, ... */ /* USER CODE END RTOS_MUTEX */ /* USER CODE BEGIN RTOS_SEMAPHORES */ /* add semaphores, ... */ /* USER CODE END RTOS_SEMAPHORES */ /* 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); /* USER CODE BEGIN RTOS_THREADS */ /* add threads, ... */ /* USER CODE END RTOS_THREADS */ /* USER CODE BEGIN RTOS_EVENTS */ /* add events, ... */ /* USER CODE END RTOS_EVENTS */ } /* 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) { /* USER CODE BEGIN StartDefaultTask */ buffer1 = (uint32_t *)malloc((sizeof(uint32_t)* BUFFER_SIZE)); buffer2 = (uint32_t *)malloc((sizeof(uint32_t)* BUFFER_SIZE)); if(NULL == buffer1) { printf("buffer1 malloc failed \r\n"); } if(NULL == buffer2) { printf("buffer2 malloc failed \r\n"); return; } printf("buffer1 , buffer2 malloc success\r\n "); memset(buffer1, 0xff , (sizeof(uint32_t)* BUFFER_SIZE)); memset(buffer2, 0xff , (sizeof(uint32_t)* BUFFER_SIZE)); printf("Unit test ADC + DMA\r\n "); xQueue1 = xQueueCreate(10 , 4 ); if(NULL == xQueue1) { printf("Queue create failed \r\n"); return ; } HAL_StatusTypeDef ret1 = HAL_OK; HAL_StatusTypeDef ret2 = HAL_OK; ret1 = HAL_ADC_Start_DMA(&hadc1, buffer1, BUFFER_SIZE); ret2 = HAL_ADC_Start_DMA(&hadc1, buffer2, BUFFER_SIZE); if(HAL_OK != ret1) { printf("HAL_ADC1 call failed "); } if(HAL_OK != ret2) { printf("HAL_ADC2 call failed "); } //UnitTest Queue send and receive BaseType_t ret_queue = pdPASS; uint32_t queue_data_2 = 0xff; ret_queue = xQueueReceive( xQueue1, &queue_data_2, 0 ); printf("xQueueSend ret_queue = [%ld]\r\n" , ret_queue); printf("xQueueReceive queue_data_2 = [%d]\r\n" , queue_data_2); /* Infinite loop */ for(;;) { printf("hello world \r\n"); //printf("buffer1 data = [%d] \r\n" , buffer1[0]); //printf("buffer2 data = [%d] \r\n" , buffer2[0]); osDelay(1000); } /* USER CODE END StartDefaultTask */ } /* Private application code --------------------------------------------------*/ /* USER CODE BEGIN Application */ void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc) { /* Prevent unused argument(s) compilation warning */ UNUSED(hadc); /* NOTE : This function Should not be modified, when the callback is needed, the HAL_ADC_ConvCpltCallback could be implemented in the user file */ printf("buffer1 data = [%d] \r\n" , buffer1[0]); BaseType_t xHigherPriorityTaskWoken; xHigherPriorityTaskWoken = pdFALSE; uint32_t dma_pattern_cplt = DMA_ADC_CPLT_INT; BaseType_t ret_queue = pdPASS; ret_queue = xQueueSendFromISR( xQueue1, &dma_pattern_cplt, &xHigherPriorityTaskWoken ); if( xHigherPriorityTaskWoken ) { taskYIELD (); } printf("QueueSend ret_queue = [%ld]\r\n" , ret_queue); } void HAL_ADC_ErrorCallback(ADC_HandleTypeDef *hadc) { /* Prevent unused argument(s) compilation warning */ UNUSED(hadc); /* NOTE : This function Should not be modified, when the callback is needed, the HAL_ADC_ErrorCallback could be implemented in the user file */ printf("ADC trasfer error \r\n"); } /* USER CODE END Application */

由此可见成功接收了数据并且在串口打印了出来

查看全文

http://www.cnnetsun.cn/news/70520.html