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从STM32开始的RoboMaster生活:进阶篇 II [Interrupt]
1.0 什么是Interrupt?中断是指计算机运行过程中,出现某些意外情况需主机干预时,机器能自动停止正在运行的程序并转入处理新情况的程序,处理完毕后又返回原被暂停的程序继续运行。 2.0 为什么需要Interrupt?在将Interrupt前,必须提一下Polling。我打个比方,比如有个快递要今天送过来,但你现在正在做RoboMaster,而快递小哥也不知道你长啥样,如果在他来的时候没来人拿,那他就走了,包裹就没了(这个传来的数据是即时的,数据可不会等你)。 如果是Polling,那就是,你一直时不时盯着小区门口,看快递小哥来没来,结果可想而知,可能一整天都没做多少RoboMaster,甚至可能在做的时候,正好小哥来了又走了,结果快递也没拿到。 那有没有办法,可以既能够放心做RoboMaster,又不用担心错过快递呢?这就是Interrupt登场的时候了,方法也很简单,让快递小哥在快递送到的时候给你打个电话(中断信号),你放下手中的RoboMaster任务(被中断),去门口拿快递(执行中断程序),拿完后继续做RoboMaster(继续被中断的任务)就行了。
3.0 STM32内部实现线路 & NVICNVIC全称为Nested Vectored Interrupt Controller,是STM32专门划分独立出来的模块,专门负责Interrupt事宜,其中技术细节和使用细节非常冗杂,但是实际在RoboMaster中能使用到的部分却是比较简单的,所以本文也不展开细说。 4.0 Interrupt的生命周期要谈这个,避免不了要讲讲Priority 优先级 为使系统能及时响应并处理发生的所有中断,系统根据引起中断事件的重要性和紧迫程度,硬件将中断源分为若干个级别,称作中断优先级。 在实际系统中,常常遇到多个中断源同时请求中断的情况,这时MCU必须确定首先为哪一个中断源服务,以及服务的次序。解决的方法是中断优先排队,即根据中断源请求的轻重缓急,排好中断处理的优先次序即优先级( Priority ),又称优先权,先响应优先级最高的中断请求。另外,当MCU正在处理某一中断时,要能响应另一个优先级更高的中断请求,而屏蔽掉同级或较低级的中断请求,形成中断嵌套。
中断优先级原则
CPU首先响应高优先级的中断请求; 如果优先级相同,MCU按查询次序响应排在前面的中断; 正在进行的中断过程不能被新的同级或低优先级的中断请求所中断; 正在进行的低优先级中断过程,能被高优先级中断请求所中断。
而在STM32中,又有两种不同的优先级
Preempt Priority
Subpriority
5.0 如何使用Interrupt - void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
- ......
- }
复制代码在<项目>/Drivers/STM32F4xx_HAL_Driver/Src的stm32f4xx_hal_gpio.c文件中,我们可以看到其定义 - __weak void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
- {
- /* Prevent unused argument(s) compilation warning */
- UNUSED(GPIO_Pin);
- /* NOTE: This function Should not be modified, when the callback is needed,
- the HAL_GPIO_EXTI_Callback could be implemented in the user file
- */
- }
复制代码这里的__weak指明了,该函数如果没被用户创建,就使用上面的代码被默认创建,而如果用户在main.c中自主创建该函数,则用户创建的函数覆盖默认定义的函数。 6.0 练习项目
6.1 项目简介与从STM32开始的RoboMaster生活:进阶篇 I [GPIO]里面的项目相同,但是用Interrupt来实现, 链接地址
6.2 芯片配置6.3 项目代码我只放了main.c,完整的工程文件可以在 这里找到! Src/main.c
- /* USER CODE BEGIN Header */
- /**
- ******************************************************************************
- * @file : main.c
- * @brief : Main program body
- ******************************************************************************
- * @attention
- *
- * <h2><center>© Copyright (c) 2020 STMicroelectronics.
- * All rights reserved.</center></h2>
- *
- * This software component is licensed by ST under BSD 3-Clause license,
- * the "License"; You may not use this file except in compliance with the
- * License. You may obtain a copy of the License at:
- * opensource.org/licenses/BSD-3-Clause
- *
- ******************************************************************************
- */
- /* USER CODE END Header */
-
- /* 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 */
- /* USER CODE END PD */
-
- /* Private macro -------------------------------------------------------------*/
- /* USER CODE BEGIN PM */
-
- /* USER CODE END PM */
-
- /* Private variables ---------------------------------------------------------*/
-
- /* USER CODE BEGIN PV */
-
- /* USER CODE END PV */
-
- /* Private function prototypes -----------------------------------------------*/
- void SystemClock_Config(void);
- static void MX_GPIO_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();
- /* USER CODE BEGIN 2 */
-
- /* 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};
-
- /** Configure the main internal regulator output voltage
- */
- __HAL_RCC_PWR_CLK_ENABLE();
- __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
- /** Initializes the CPU, AHB and APB busses clocks
- */
- 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 busses 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 GPIO Initialization Function
- * @param None
- * @retval None
- */
- static void MX_GPIO_Init(void)
- {
- GPIO_InitTypeDef GPIO_InitStruct = {0};
-
- /* GPIO Ports Clock Enable */
- __HAL_RCC_GPIOG_CLK_ENABLE();
- __HAL_RCC_GPIOB_CLK_ENABLE();
- __HAL_RCC_GPIOE_CLK_ENABLE();
- __HAL_RCC_GPIOF_CLK_ENABLE();
-
- /*Configure GPIO pin Output Level */
- HAL_GPIO_WritePin(GPIOG, LD8_Pin|LD7_Pin|LD6_Pin|LD5_Pin
- |LD4_Pin|LD3_Pin|LD2_Pin|LD1_Pin, GPIO_PIN_RESET);
-
- /*Configure GPIO pin Output Level */
- HAL_GPIO_WritePin(LD_RED_GPIO_Port, LD_RED_Pin, GPIO_PIN_RESET);
-
- /*Configure GPIO pin Output Level */
- HAL_GPIO_WritePin(LD_GREEN_GPIO_Port, LD_GREEN_Pin, GPIO_PIN_RESET);
-
- /*Configure GPIO pins : LD8_Pin LD7_Pin LD6_Pin LD5_Pin
- LD4_Pin LD3_Pin LD2_Pin LD1_Pin */
- GPIO_InitStruct.Pin = LD8_Pin|LD7_Pin|LD6_Pin|LD5_Pin
- |LD4_Pin|LD3_Pin|LD2_Pin|LD1_Pin;
- GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
- HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
-
- /*Configure GPIO pin : Button_Pin */
- GPIO_InitStruct.Pin = Button_Pin;
- GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- HAL_GPIO_Init(Button_GPIO_Port, &GPIO_InitStruct);
-
- /*Configure GPIO pin : LD_RED_Pin */
- GPIO_InitStruct.Pin = LD_RED_Pin;
- GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
- HAL_GPIO_Init(LD_RED_GPIO_Port, &GPIO_InitStruct);
-
- /*Configure GPIO pin : LD_GREEN_Pin */
- GPIO_InitStruct.Pin = LD_GREEN_Pin;
- GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
- GPIO_InitStruct.Pull = GPIO_NOPULL;
- GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
- HAL_GPIO_Init(LD_GREEN_GPIO_Port, &GPIO_InitStruct);
-
- /* EXTI interrupt init*/
- HAL_NVIC_SetPriority(EXTI2_IRQn, 1, 0);
- HAL_NVIC_EnableIRQ(EXTI2_IRQn);
-
- }
-
- /* USER CODE BEGIN 4 */
- void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
- if(GPIO_Pin == Button_Pin){
- HAL_Delay(500);
- HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD_GREEN_GPIO_Port,LD_GREEN_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD1_GPIO_Port,LD1_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD2_GPIO_Port,LD2_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD3_GPIO_Port,LD3_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD4_GPIO_Port,LD4_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD5_GPIO_Port,LD5_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD6_GPIO_Port,LD6_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD7_GPIO_Port,LD7_Pin);
- HAL_Delay(100);
- HAL_GPIO_TogglePin(LD8_GPIO_Port,LD8_Pin);
- }
- }
- /* 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 */
-
- /* 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,
- tex: 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****/
复制代码
6.4 效果展示效果与从STM32开始的RoboMaster生活:进阶篇 I [GPIO]里面展示的相同, 链接地址
本文已经同步发布于作者部署的私人博客 为了更好的排版和观看体验 |