HAL库之UART（STM32 HAL库学习笔记）

小李不想当小白2026-11-10 10:38

在上一篇《STM32 HAL 库学习笔记》中，我们通过 GPIO 章节完成了对 HAL 库开发流程的第一次实践：从 CubeMX 的引脚配置、时钟树设置，到 HAL_GPIO_WritePin()、HAL_GPIO_ReadPin() 等常用 API 的调用，初步体会到了 HAL 库"以句柄为中心、以函数封装寄存器"的设计思路。可以说，GPIO 让我们学会了如何让单片机的引脚"动起来"。

而本篇要聊的 UART，则是 STM32 与外部世界"对话"的第一种方式。作为最经典、最常用的串行通信外设，UART 几乎是每个嵌入式项目的标配：调试信息输出、模块通信、上位机交互，都离不开它。相比 GPIO 的"电平高低"，UART 涉及波特率、数据位、停止位、校验位等更多参数，也更考验对通信时序和帧格式的理解。

因此，本文将继续沿用"CubeMX 配置 + HAL 库 API + 实验验证"的节奏，先梳理 UART 的基础知识与帧格式，再通过简单数据发送实验和简单数据接收实验，分别演示 HAL_UART_Transmit() 与 HAL_UART_Receive() 的使用方法，并结合实际踩坑记录，帮助你把串口通信真正跑通。如果你已经跟着上一篇把 GPIO 玩明白了，那么这一篇的 UART 正好可以顺势接上。

如果觉得有收获可以为我的文章点点小赞，这将激励我创作更好的内容！谢谢！

一、HAL库之 UART****************************************************************************************************************************************************************************************************************************************************************

1.UART基础知识

2.UART基础知识简单数据发送实验

接线图：

//读取IO的当前值

HAL_StatusTypeDef HAL_UART_Transmit(UART_HandleTypeDef *huart,

uint8_t *pData,

uint16_t Size,

uint32_t Timeout)

main.c ↓

-----------------------------

cpp 复制代码 
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2026 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"
/* 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 ---------------------------------------------------------*/
UART_HandleTypeDef huart1;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_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();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
uint8_t ByteNumber = 0x5A;
uint8_t ByteArray[] = {1,2,3,4,5};
char ch = 'a';
char *str = "Hello world";
HAL_UART_Transmit(&amp;huart1,&amp;ByteNumber,1,HAL_MAX_DELAY);
HAL_UART_Transmit(&amp;huart1,ByteArray,5,HAL_MAX_DELAY);
HAL_UART_Transmit(&amp;huart1,(uint8_t *)&amp;ch,1,HAL_MAX_DELAY);
HAL_UART_Transmit(&amp;huart1,(uint8_t *)str,strlen(str),HAL_MAX_DELAY);
/* 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};
/** Initializes the RCC Oscillators according to the specified parameters
in the RCC_OscInitTypeDef structure.
*/
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 buses 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 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 */
}
/**
@brief GPIO Initialization Function
@param None
@retval None
/
static void MX_GPIO_Init(void)
{
/ USER CODE BEGIN MX_GPIO_Init_1 /
/ USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOA_CLK_ENABLE();
/* USER CODE BEGIN MX_GPIO_Init_2 /
/ USER CODE END MX_GPIO_Init_2 */
}
/* 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 */

-----------------------------

3.UART简单数据接收实验

3.1 实验

main.c ↓

-----------------------------

cpp 复制代码 
/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2026 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"
/* 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 ---------------------------------------------------------*/
UART_HandleTypeDef huart1;
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_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();
MX_USART1_UART_Init();
/ USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{	
uint8_t DataRcvd;
HAL_UART_Receive(&huart1,&DataRcvd,1,HAL_MAX_DELAY);
	if(DataRcvd == '0')
	{
		HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_RESET);
	}
	else if(DataRcvd == '1')
	{
		HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_SET);			
	}
/* 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_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 buses 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 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 /
}
/*
@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_GPIOA_CLK_ENABLE();
/*Configure GPIO pin Output Level /
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_SET);
/Configure GPIO pin : PC13 /
GPIO_InitStruct.Pin = GPIO_PIN_13;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/ USER CODE BEGIN MX_GPIO_Init_2 /
/ USER CODE END MX_GPIO_Init_2 /
}
/ 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 */

-----------------------------

3.2 遇到的问题

问题：发送0和1 PC13口的LED灯没有反应？

原因： 1.没有将代码写在一对 /* USER CODE BEGIN WHILE */ 和 /* USER CODE END WHILE */ 之间；

2.给stm32下载程序后没有按一下最小系统板的复位键。

二、总结

本文围绕 STM32 HAL 库的 UART 功能，从基础知识到收发实验做了一次完整的梳理。首先介绍了 UART 的通信原理、帧格式以及波特率、数据位、停止位、校验位等关键参数，帮助理解串口通信的底层机制；随后通过 CubeMX 配置 USART1，完成了简单数据发送实验，分别演示了单字节、数组、字符和字符串的发送方式，并重点说明了 HAL_UART_Transmit() 各参数的含义与使用要点。

在接收实验中，使用 HAL_UART_Receive() 阻塞方式读取串口数据，并根据收到的字符控制 PC13 引脚上的 LED 灯，实现了"发送 0 灭灯、发送 1 亮灯"的交互效果。同时记录了实验过程中遇到的两个典型问题：代码必须写在一对 /* USER CODE BEGIN WHILE */ 和 /* USER CODE END WHILE */ 之间，否则会被 CubeMX 重新生成代码时覆盖；下载程序后需要按一下最小系统板的复位键，程序才会真正运行。

整体来看，HAL 库把 UART 的寄存器操作封装成了简洁的 API，配合 CubeMX 可以快速完成串口初始化与收发功能开发。掌握本文的发送与接收流程后，可以进一步尝试串口中断接收、DMA 传输以及自定义协议解析等进阶用法，为后续的通信类项目打下基础。

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