STM32 —— 串口通信2 、中断2 STM32 中断方式串口通信（不定长已知内容或定长字符串）
STM32 —— 串口通信2 、中断2 STM32 中断方式串口通信（不定长已知内容或定长字符串）
实验目的
采用串口中断方式重做上周的串口通信作业，分别实现：
当 stm32 接收到字符 “s” 时，停止持续发送 “hello windows!” ; 当接收到字符“t”时，持续发送 “hello windows!”（提示：采用一个全局标量做信号灯）
当stm32接收到字符“stop stm32!”时，停止持续发送“hello windows!”
当接收到字符“go stm32!”时，持续发送“hello windows!”
提示：要将接收到的连续字符保存到一个字符数组里，进行判别匹配。写一个接收字符串的函数
实验原理
实验原理在我的另一篇博客中有详细的介绍：STM32 —— 串口定长数据接收
HAL 库方法
CubeMX 项目配置
设置 RCC
配置如图：
设置好外部晶振之后，需要设置时钟周期为 72 MHz
设置 SYS
用于设置并控制板载灯泡
设置 USART
将串口 USART1 设置为异步通信模式
设置 NVIC
将串口 USART1 设置为默认全局中断
代码设计
定长字符串接收
首先，我们需要一个布尔类型变量用来判断串口是否中断，并且在输入是要向上位机发送对应的回复，所以，数据定义如下：
bool flag = false;
char c; // 输入的数据，t 是开始持续发送，s 是中断发送
uint8_t str[] = "Hello ppqppl !\r\n"; // 输出数据
uint8_t tips[] = "input error !\r\n"; // 输入错误
uint8_t stop[] = "STOP !\r\n"; // 中断发送
uint8_t start[] = "START !\r\n"; // 开始发送
注意：默认引入 bool 变量时会报错，所以，如果需要使用 bool 变量类型，需要引入头文件 stdbool.h
然后我们需要接收数据，HAL 库中已经有接收固定长度数据的函数，我们只需要直接调用即可，这里我们把串口接收函数写在主函数中的循环之前：
HAL_UART_Receive_IT(&huart1,(uint8_t *)&c,1);
// 函数的三个参数分别是：接收的串口，接收的数据，数据的长度
我们成功接收数据后，需要思考我们如何使串口产生中断，在 stm32f1xx_it.c 中我们可以找到使串口产生中断的函数：
void USART1_IRQHandler(void)
而这个函数主要是通过这个函数来执行中断事件：
void HAL_UART_IRQHandler(&huart1);
如果没有明白为什么要使用这个函数，请看我的另一篇博客：STM32 —— 串口定长数据接收
我们只需要重写这个函数即可:
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
switch(c){
case 's':{
flag = false;
HAL_UART_Transmit(huart,(uint8_t *)stop,COUNTOF(stop),0xFFFF);
break;
}
case 't':{
flag = true;
HAL_UART_Transmit(huart,(uint8_t *)start,COUNTOF(start),0xFFFF);
break;
}
default:{
flag = false;
HAL_UART_Transmit(huart,(uint8_t *)tips,COUNTOF(tips),0xFFFF);
break;
}
}
HAL_UART_Receive_IT(&huart1, (uint8_t *)&c, 1); // 由于我们是根据输入来判断中断，而且要求程序可以多次输入，所以这里每次中断判断后都要重新获取 c 的值
}
最后，我们只需要在主函数的循环中加上判断即可：
if(flag)
{
HAL_UART_Transmit(&huart1,(uint8_t *)str,COUNTOF(str),0xFFFF);
HAL_Delay(500);
}
完整的 main.c 代码如下：
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2022 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"
#include <stdbool.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);
/* 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
*/
#define COUNTOF(a) (sizeof(a)/sizeof(*(a)))
bool flag = false;
char c;
uint8_t str[] = "Hello ppqppl !\r\n";
uint8_t tips[] = "input error !\r\n";
uint8_t stop[] = "STOP !\r\n";
uint8_t start[] = "START !\r\n";
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
switch(c){
case 's':{
flag = false;
HAL_UART_Transmit(huart,(uint8_t *)stop,COUNTOF(stop),0xFFFF);
break;
}
case 't':{
flag = true;
HAL_UART_Transmit(huart,(uint8_t *)start,COUNTOF(start),0xFFFF);
break;
}
default:{
flag = false;
HAL_UART_Transmit(huart,(uint8_t *)tips,COUNTOF(tips),0xFFFF);
break;
}
}
HAL_UART_Receive_IT(&huart1, (uint8_t *)&c, 1);
}
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 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
HAL_UART_Receive_IT(&huart1,(uint8_t *)&c,1);
while (1)
{
if(flag){
HAL_UART_Transmit(&huart1,(uint8_t *)str,COUNTOF(str),0xFFFF);
HAL_Delay(500);
}
/* 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 */
/* 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 */
不定长已知内容字符串接收
原理与上面类似，知识每次接收一个字符，然后讲字符存储到字符串中，每次中断都进行比对，当比对成功，通过判断改变 bool 变量的值，从而影响输出
主要代码如下
#define COUNTOF(a)(sizeof(a)/sizeof(*(a)))
char getBuffer[100];
char value;
char str1[] = "go ppqppl!";
char str2[] = "stop ppqppl!";
uint8_t out1[] = "start!\r\n";
uint8_t out2[] = "stop!\r\n";
uint8_t str[] = "Hello ppqppl!\r\n";
bool flag = false;
int countofGetBuffer = 0;
void USART1_IRQHandler(void)
{
HAL_UART_IRQHandler(&huart1); //该函数会清空中断标志，取消中断使能，并间接调用回调函数
getBuffer[countofGetBuffer++] = value;
if(strcmp(str1,getBuffer) == 0) // 这里把判断长度改为判断内容
{
HAL_UART_Transmit(&huart1,(uint8_t *)out1,COUNTOF(out1),0xFFFF);
flag = true;
countofGetBuffer = 0;
memset(getBuffer,0,COUNTOF(getBuffer));
}
else if(strcmp(str2,getBuffer) == 0)
{
flag = false;
HAL_UART_Transmit(&huart1,(uint8_t *)out2,COUNTOF(out2),0xFFFF);
HAL_Delay(500);
countofGetBuffer = 0;
memset(getBuffer,0,COUNTOF(getBuffer));
}
HAL_UART_Receive_IT(&huart1, (uint8_t *)&value,1); //由于接收中断是每接收一个字符便进入一次，所以这一行代码必须添加，否则只能接收一个字符，而无法接收整个字符串
}
注意：这里再重写函数是需要将 stm32f1xx_it.c 中的函数删掉，否则会出现重定义的报错
完整的 main.c 代码如下：
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2022 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"
#include <stdbool.h>
#include <string.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);
/* 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
*/
#define COUNTOF(a)(sizeof(a)/sizeof(*(a)))
char getBuffer[100];
char value;
char str1[] = "go ppqppl!";
char str2[] = "stop ppqppl!";
uint8_t out1[] = "start!\r\n";
uint8_t out2[] = "stop!\r\n";
uint8_t str[] = "Hello ppqppl!\r\n";
bool flag = false;
int countofGetBuffer = 0;
void USART1_IRQHandler(void)
{
HAL_UART_IRQHandler(&huart1); //该函数会清空中断标志，取消中断使能，并间接调用回调函数
getBuffer[countofGetBuffer++] = value;
if(strcmp(str1,getBuffer) == 0) // 这里把判断长度改为判断内容
{
HAL_UART_Transmit(&huart1,(uint8_t *)out1,COUNTOF(out1),0xFFFF);
flag = true;
countofGetBuffer = 0;
memset(getBuffer,0,COUNTOF(getBuffer));
}
else if(strcmp(str2,getBuffer) == 0)
{
flag = false;
HAL_UART_Transmit(&huart1,(uint8_t *)out2,COUNTOF(out2),0xFFFF);
HAL_Delay(500);
countofGetBuffer = 0;
memset(getBuffer,0,COUNTOF(getBuffer));
}
HAL_UART_Receive_IT(&huart1, (uint8_t *)&value,1); //由于接收中断是每接收一个字符便进入一次，所以这一行代码必须添加，否则只能接收一个字符，而无法接收整个字符串
}
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 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
HAL_UART_Receive_IT(&huart1,(uint8_t *)&value,1);
while (1)
{
if(flag){
HAL_UART_Transmit(&huart1,(uint8_t *)str,COUNTOF(str),0xFFFF);
HAL_Delay(500);
}
/* 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 */
/* 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 */
标准库方法
若有需要，后续会更新标准库写法
寄存器方法
若有需要，后续会更新寄存器写法
运行测试
虚拟串口调试
由于在调试程序时，每次修改代码后重新编译生成 hex 文件并多次烧录比较麻烦，所以这里采用仿真运行，并在 keil 中使用虚拟串口调试
调试工具下载连接：虚拟串口驱动程序_Virtual Serial Port Driver(中文和谐版)
安装好之后，我们将两个空闲串口进行绑定，这里采用将 COM3 与 COM2 进行绑定使用：
在选择好目标端口后，点击添加端口即可
如果左边已经出现了虚拟端口，就说明端口绑定成功：
然后我们在 keil 中启动仿真运行，在左下角命令窗口输入如下命令即可绑定串口：
MODE COM2 15200,n,8,1
函数源码如下：
MODE COMx baudrate, parity, databits, stopbits
/*
COMx 表示计算机的串口
baudrate 表示串口的波特率
parity 表示校验方式，即 n 表示无校验位，0 表示偶校验，1 表示奇校验
stopbits 表示停止位长度
*/
绑定串口后，需要将计算机的串口绑定到单片机上：
ASSIGN COM2 < S3IN > S3OUT
函数源码如下：
ASSIGN COMx < SIN > SOUT
/*
COMx 表示计算机的串口
SIN 和 SOUT 表示绑定的单片机的输入和输出串口
*/
绑定如下：
绑定完全成功后，就可以使用串口调试工具进行仿真串口调试了
虚拟串口测试结果
接收单字符：
接收不定长已知内容字符串：
测试接收不定长已知内容字符串的时候忘记加延时了，导致上位机端接收有点小问题，加上延时之后就没问题了
接线示例
运行结果
波形检测
我们通过仿真虚拟串口调试的方式进行波形检测
与串口发送 Hello Windows 波形相同，产生原因也不尽相同
错误解决方法
目前尚未发现报错，如有报错会及时更新修改方法
