串口中断接收数据
117.4.7串口中断接收数据
/* ==================== Core\Inc\main.h ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.h
* @brief : Header for main.c file.
* This file contains the common defines of the application.
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __MAIN_H
#define __MAIN_H
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "stm32f1xx_hal.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */
/* USER CODE END ET */
/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */
/* USER CODE END EC */
/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */
/* USER CODE END EM */
/* Exported functions prototypes ---------------------------------------------*/
void Error_Handler(void);
/* USER CODE BEGIN EFP */
/* USER CODE END EFP */
/* Private defines -----------------------------------------------------------*/
#define LED2_Pin GPIO_PIN_5
#define LED2_GPIO_Port GPIOE
#define LED1_Pin GPIO_PIN_5
#define LED1_GPIO_Port GPIOB
/* USER CODE BEGIN Private defines */
/* USER CODE END Private defines */
#ifdef __cplusplus
}
#endif
#endif /* __MAIN_H */
/* ==================== Core\Inc\gpio.h ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file gpio.h
* @brief This file contains all the function prototypes for
* the gpio.c file
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __GPIO_H__
#define __GPIO_H__
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* USER CODE BEGIN Private defines */
/* USER CODE END Private defines */
void MX_GPIO_Init(void);
/* USER CODE BEGIN Prototypes */
/* USER CODE END Prototypes */
#ifdef __cplusplus
}
#endif
#endif /*__ GPIO_H__ */
/* ==================== Core\Inc\usart.h ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file usart.h
* @brief This file contains all the function prototypes for
* the usart.c file
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __USART_H__
#define __USART_H__
#ifdef __cplusplus
extern "C" {
#endif
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
extern UART_HandleTypeDef huart1;
/* USER CODE BEGIN Private defines */
/* USER CODE END Private defines */
void MX_USART1_UART_Init(void);
/* USER CODE BEGIN Prototypes */
/* USER CODE END Prototypes */
#ifdef __cplusplus
}
#endif
#endif /* __USART_H__ */
/* ==================== Core\Inc\stm32f1xx_it.h ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file stm32f1xx_it.h
* @brief This file contains the headers of the interrupt handlers.
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __STM32F1xx_IT_H
#define __STM32F1xx_IT_H
#ifdef __cplusplus
extern "C" {
#endif
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Exported types ------------------------------------------------------------*/
/* USER CODE BEGIN ET */
/* USER CODE END ET */
/* Exported constants --------------------------------------------------------*/
/* USER CODE BEGIN EC */
/* USER CODE END EC */
/* Exported macro ------------------------------------------------------------*/
/* USER CODE BEGIN EM */
/* USER CODE END EM */
/* Exported functions prototypes ---------------------------------------------*/
void NMI_Handler(void);
void HardFault_Handler(void);
void MemManage_Handler(void);
void BusFault_Handler(void);
void UsageFault_Handler(void);
void SVC_Handler(void);
void DebugMon_Handler(void);
void PendSV_Handler(void);
void SysTick_Handler(void);
void USART1_IRQHandler(void);
/* USER CODE BEGIN EFP */
/* USER CODE END EFP */
#ifdef __cplusplus
}
#endif
#endif /* __STM32F1xx_IT_H */
/* ==================== Core\Src\main.c ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <string.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 ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
uint8_t UART_Recv_IT[5];
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(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_USART1_UART_Init();
/* USER CODE BEGIN 2 */
HAL_UART_Receive_IT(&huart1, UART_Recv_IT, 4);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
HAL_UART_Transmit_IT(&huart1, "i am wfeng\n", strlen("i am wfeng\n"));
HAL_Delay(1000);
/* 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();
}
}
/* USER CODE BEGIN 4 */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if(huart ==&huart1)
{
if(strcmp("LED1", (char *)UART_Recv_IT)==0)
{
HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
memset(UART_Recv_IT, '\0', 5);
}
if(!strcmp("LED2", (char *)UART_Recv_IT))
{
HAL_GPIO_TogglePin(LED2_GPIO_Port, LED2_Pin);
memset(UART_Recv_IT, '\0', 5);
}
HAL_UART_Receive_IT(&huart1, UART_Recv_IT, 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 */
/* ==================== Core\Src\gpio.c ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file gpio.c
* @brief This file provides code for the configuration
* of all used GPIO pins.
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "gpio.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/*----------------------------------------------------------------------------*/
/* Configure GPIO */
/*----------------------------------------------------------------------------*/
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/** Configure pins as
* Analog
* Input
* Output
* EVENT_OUT
* EXTI
*/
void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOE_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(LED2_GPIO_Port, LED2_Pin, GPIO_PIN_SET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(LED1_GPIO_Port, LED1_Pin, GPIO_PIN_SET);
/*Configure GPIO pin : PtPin */
GPIO_InitStruct.Pin = LED2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(LED2_GPIO_Port, &GPIO_InitStruct);
/*Configure GPIO pin : PtPin */
GPIO_InitStruct.Pin = LED1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(LED1_GPIO_Port, &GPIO_InitStruct);
}
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* ==================== Core\Src\usart.c ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file usart.c
* @brief This file provides code for the configuration
* of the USART instances.
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "usart.h"
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
UART_HandleTypeDef huart1;
/* USART1 init function */
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 */
}
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspInit 0 */
/* USER CODE END USART1_MspInit 0 */
/* USART1 clock enable */
__HAL_RCC_USART1_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
GPIO_InitStruct.Pin = GPIO_PIN_9;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
GPIO_InitStruct.Pin = GPIO_PIN_10;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USART1 interrupt Init */
HAL_NVIC_SetPriority(USART1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART1_MspInit 1 */
/* USER CODE END USART1_MspInit 1 */
}
}
void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{
if(uartHandle->Instance==USART1)
{
/* USER CODE BEGIN USART1_MspDeInit 0 */
/* USER CODE END USART1_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_USART1_CLK_DISABLE();
/**USART1 GPIO Configuration
PA9 ------> USART1_TX
PA10 ------> USART1_RX
*/
HAL_GPIO_DeInit(GPIOA, GPIO_PIN_9|GPIO_PIN_10);
/* USART1 interrupt Deinit */
HAL_NVIC_DisableIRQ(USART1_IRQn);
/* USER CODE BEGIN USART1_MspDeInit 1 */
/* USER CODE END USART1_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* ==================== Core\Src\stm32f1xx_it.c ==================== */
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file stm32f1xx_it.c
* @brief Interrupt Service Routines.
******************************************************************************
* @attention
*
* Copyright (c) 2024 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.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f1xx_it.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD */
/* USER CODE END TD */
/* 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 -----------------------------------------------*/
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/* External variables --------------------------------------------------------*/
extern UART_HandleTypeDef huart1;
/* USER CODE BEGIN EV */
/* USER CODE END EV */
/******************************************************************************/
/* Cortex-M3 Processor Interruption and Exception Handlers */
/******************************************************************************/
/**
* @brief This function handles Non maskable interrupt.
*/
void NMI_Handler(void)
{
/* USER CODE BEGIN NonMaskableInt_IRQn 0 */
/* USER CODE END NonMaskableInt_IRQn 0 */
/* USER CODE BEGIN NonMaskableInt_IRQn 1 */
while (1)
{
}
/* USER CODE END NonMaskableInt_IRQn 1 */
}
/**
* @brief This function handles Hard fault interrupt.
*/
void HardFault_Handler(void)
{
/* USER CODE BEGIN HardFault_IRQn 0 */
/* USER CODE END HardFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_HardFault_IRQn 0 */
/* USER CODE END W1_HardFault_IRQn 0 */
}
}
/**
* @brief This function handles Memory management fault.
*/
void MemManage_Handler(void)
{
/* USER CODE BEGIN MemoryManagement_IRQn 0 */
/* USER CODE END MemoryManagement_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
/* USER CODE END W1_MemoryManagement_IRQn 0 */
}
}
/**
* @brief This function handles Prefetch fault, memory access fault.
*/
void BusFault_Handler(void)
{
/* USER CODE BEGIN BusFault_IRQn 0 */
/* USER CODE END BusFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_BusFault_IRQn 0 */
/* USER CODE END W1_BusFault_IRQn 0 */
}
}
/**
* @brief This function handles Undefined instruction or illegal state.
*/
void UsageFault_Handler(void)
{
/* USER CODE BEGIN UsageFault_IRQn 0 */
/* USER CODE END UsageFault_IRQn 0 */
while (1)
{
/* USER CODE BEGIN W1_UsageFault_IRQn 0 */
/* USER CODE END W1_UsageFault_IRQn 0 */
}
}
/**
* @brief This function handles System service call via SWI instruction.
*/
void SVC_Handler(void)
{
/* USER CODE BEGIN SVCall_IRQn 0 */
/* USER CODE END SVCall_IRQn 0 */
/* USER CODE BEGIN SVCall_IRQn 1 */
/* USER CODE END SVCall_IRQn 1 */
}
/**
* @brief This function handles Debug monitor.
*/
void DebugMon_Handler(void)
{
/* USER CODE BEGIN DebugMonitor_IRQn 0 */
/* USER CODE END DebugMonitor_IRQn 0 */
/* USER CODE BEGIN DebugMonitor_IRQn 1 */
/* USER CODE END DebugMonitor_IRQn 1 */
}
/**
* @brief This function handles Pendable request for system service.
*/
void PendSV_Handler(void)
{
/* USER CODE BEGIN PendSV_IRQn 0 */
/* USER CODE END PendSV_IRQn 0 */
/* USER CODE BEGIN PendSV_IRQn 1 */
/* USER CODE END PendSV_IRQn 1 */
}
/**
* @brief This function handles System tick timer.
*/
void SysTick_Handler(void)
{
/* USER CODE BEGIN SysTick_IRQn 0 */
/* USER CODE END SysTick_IRQn 0 */
HAL_IncTick();
/* USER CODE BEGIN SysTick_IRQn 1 */
/* USER CODE END SysTick_IRQn 1 */
}
/******************************************************************************/
/* STM32F1xx Peripheral Interrupt Handlers */
/* Add here the Interrupt Handlers for the used peripherals. */
/* For the available peripheral interrupt handler names, */
/* please refer to the startup file (startup_stm32f1xx.s). */
/******************************************************************************/
/**
* @brief This function handles USART1 global interrupt.
*/
void USART1_IRQHandler(void)
{
/* USER CODE BEGIN USART1_IRQn 0 */
/* USER CODE END USART1_IRQn 0 */
HAL_UART_IRQHandler(&huart1);
/* USER CODE BEGIN USART1_IRQn 1 */
/* USER CODE END USART1_IRQn 1 */
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
一、串口中断接收数据
1.1 上节回顾
轮询接收会让 CPU 停在 HAL_UART_Receive() 中反复等待。中断接收则先“登记一项接收任务”，随后主循环继续运行；USART 收到字节时触发中断，HAL 完成规定数量的数据后调用回调函数。
1.2 中断接收数据
1.2.1 初始化工程
以 03UART 为基础建立 04UART_IT 工程，保留 USART1、PB5、PE5 和 72 MHz 时钟配置。工程目标仍是接收 4 字节 LED1 或 LED2，但不再在主循环里阻塞等待。
1.2.2 配置硬件
USART1 使用 PA9/TX、PA10/RX，波特率 115200、8N1。开发板通过 CH340C 接电脑；LED1 为 PB5，LED2 为 PE5，均为低电平点亮。
1.2.3 初始化
1.2.3.1 配置串口
除基本参数外，需要在 CubeMX 的 NVIC Settings 中启用 USART1 global interrupt。生成代码后，USART1_IRQHandler() 会调用：
HAL_UART_IRQHandler(&huart1);
它统一检查 RXNE、错误和发送/接收状态，并在接收任务完成时进入用户回调。
1.2.3.2 配置灯
PB5、PE5 配置为推挽输出并默认置高。回调中只调用 HAL_GPIO_TogglePin() 翻转灯状态，处理时间较短。
1.2.4 编写串口接收代码
定义 5 字节缓冲区：
uint8_t UART_Recv_IT[5];
实际接收长度是 4，第 5 字节保留为 '\0'，便于按字符串比较。
1.2.4.1 main函数分析
进入 while (1) 前调用一次：
HAL_UART_Receive_IT(&huart1, UART_Recv_IT, 4);
这不是“永久打开串口中断”，而是启动一次长度为 4 的异步接收事务。函数随即返回，主循环可以执行其他任务。
1.2.4.2 库函数接口
接口原型：
HAL_StatusTypeDef HAL_UART_Receive_IT(
UART_HandleTypeDef *huart,
uint8_t *pData,
uint16_t Size);
没有超时参数。若同一串口已有接收任务，可能返回 HAL_BUSY；句柄或参数异常会返回错误状态。因此正式代码应检查返回值。
1.2.4.3 串口中断传输函数
中断接收的调用链为：
flowchart TD
A[HAL_UART_Receive_IT登记缓冲区和长度] --> B[USART收到字节]
B --> C[硬件置RXNE并请求USART1中断]
C --> D[USART1_IRQHandler]
D --> E[HAL_UART_IRQHandler读取DR并写入缓冲区]
E --> F{已收满4字节?}
F -- 否 --> B
F -- 是 --> G[HAL_UART_RxCpltCallback]
G --> H[处理命令并再次启动接收]
STM32F1 USART 状态寄存器中，本节最相关的位是 RXNE、ORE、FE、NE、PE；控制寄存器 CR1 中 RXNEIE 允许 RXNE/ORE 产生中断，UE 使能 USART，RE/TE 分别使能接收和发送。HAL 会维护这些位和内部状态，应用层一般不必直接改寄存器。
1.2.4.4 回调函数介绍
接收完成回调的函数名和参数必须与 HAL 声明一致：
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
它可能被任意已启用的 UART 调用，所以必须判断来源。回调运行在中断上下文中，应保持简短，不应执行长时间延时、阻塞等待或大量格式化输出。
1.2.4.5 编写用户代码
工程中的关键逻辑为：
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart == &huart1)
{
UART_Recv_IT[4] = '\0';
if (strcmp("LED1", (char *)UART_Recv_IT) == 0)
HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
else if (strcmp("LED2", (char *)UART_Recv_IT) == 0)
HAL_GPIO_TogglePin(LED2_GPIO_Port, LED2_Pin);
memset(UART_Recv_IT, 0, sizeof(UART_Recv_IT));
HAL_UART_Receive_IT(&huart1, UART_Recv_IT, 4);
}
}
再次调用接收函数必须放在处理完成之后，否则缓冲区可能在比较或清零期间被下一批数据改写。
二、串口中断接收数据
2.1 串口中断接收数据的基本代码结构
完整生命周期是“定义缓冲区→初始化一次→硬件收满固定长度→进入回调→处理→重新装载”。回调不会自动让下一轮接收持续进行，漏掉最后一步就只能成功一次。
2.2 串口中断接收数据的配置与测试
测试顺序：
- 打开 USART1 全局中断；
- 确认 USART1 IRQ Handler 调用 HAL；
- 在主循环前检查第一次
HAL_UART_Receive_IT()是否返回HAL_OK； - 串口助手关闭自动追加回车换行，发送正好 4 字节；
- 分别发送
LED1、LED2，观察对应 LED 翻转。
若自动追加 \r\n，多出的两个字节会进入下一次 4 字节接收，后续命令边界就会错位。
2.3 串口中断接收数据的处理逻辑
固定长度接收适合长度确定的命令。先把第 5 字节设为 0，再比较前 4 字节。对于二进制数据或可能包含 0 的内容，应使用长度明确的 memcmp()，不能依赖 strcmp()。
异常处理也不能忽略。噪声、帧错误或溢出可能使接收停止，工程可实现 HAL_UART_ErrorCallback()，记录 huart->ErrorCode，清理状态后重新启动接收。
2.4 串口中断接收数据的持续接收方法
最简方法是在完成回调末尾重新调用 HAL_UART_Receive_IT()。数据较多时，更好的结构是回调只把数据复制进环形缓冲区或设置事件标志，让主循环解析命令，以缩短中断占用时间。
中断层：快速收字节 → 放入队列 → 立即退出
任务层：从队列取数据 → 找帧头/长度/校验 → 执行业务
2.5 串口中断接收数据的实验验证
可以在回调入口设置断点或翻转调试 GPIO，但断点停住 CPU 时串口仍可能继续发送，从而造成溢出。更可靠的验证方式是计数回调次数、记录错误码，或将短日志放入待发送队列。
2.6 多个串口中断接收数据的处理
多个 UART 共用同名 HAL 回调，使用句柄区分：
if (huart->Instance == USART1)
{
/* USART1数据 */
}
else if (huart->Instance == USART2)
{
/* USART2数据 */
}
每个串口必须拥有独立缓冲区、独立接收长度和独立的重新装载调用，不能让两个 DMA/中断接收任务写入同一块内存。
2.7 串口中断接收数据的最终测试与总结
普通中断接收解决了主循环阻塞问题，但本例仍要求固定 4 字节。若协议帧长不固定，仅靠“收满 N 字节”无法及时判断帧结束，可改用带长度字段的状态机，或使用后续的 USART 空闲事件配合 DMA。
三、串口中断发送
中断发送接口为：
HAL_UART_Transmit_IT(&huart1,
(uint8_t *)"i am wfeng\r\n",
strlen("i am wfeng\r\n"));
函数启动发送后立即返回，缓冲区在 HAL_UART_TxCpltCallback() 发生之前必须一直有效。字符串字面量始终有效，但局部数组如果提前退出作用域，或发送期间被修改，就会造成数据错误。
上一项发送尚未完成时再次调用通常返回 HAL_BUSY，所以不能只依赖固定 HAL_Delay(1000) 猜测它已经结束。正式项目应检查返回值，并在发送完成回调中启动下一项，或使用发送队列。