参考：http://t.csdn.cn/NXP9Q
    引脚
    image.png
    串口发送函数：

    1. HAL_UART_Transmit(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size, uint32_t Timeout)
    2. HAL_UART_Transmit(&huart1, "TMD", 3, 0xffff);   //串口发送三个字节数据，最大传输时间0xffff

    中断接收

    1.       HAL_UART_Transmit(&huart1, "TMD", 3, 0xffff);   //串口发送三个字节数据，最大传输时间0xffff
    2.       HAL_Delay(1000);
    3.       HAL_UART_Receive_IT(&huart1,(uint8_t *)&value,1);   //中断接收一个字符，存储到value中
    5.       HAL_UART_Transmit(&huart1, (uint8_t *)&value, 1, 0xffff);
    6.       HAL_Delay(1000);

    中断发送

    1. HAL_UART_Transmit_IT(&huart1, "TMD", 2);
    2.       HAL_Delay(1000);

    发送数据被正常返回，需要添加哪些函数：

    1. /* USER CODE BEGIN Header */
    2. /**
    3.   ******************************************************************************
    4.   * @file           : main.c
    5.   * @brief          : Main program body
    6.   ******************************************************************************
    7.   * @attention
    8.   *
    9.   * Copyright (c) 2022 STMicroelectronics.
    10.   * All rights reserved.
    11.   *
    12.   * This software is licensed under terms that can be found in the LICENSE file
    13.   * in the root directory of this software component.
    14.   * If no LICENSE file comes with this software, it is provided AS-IS.
    15.   *
    16.   ******************************************************************************
    17.   */
    18. /* USER CODE END Header */
    19. /* Includes ------------------------------------------------------------------*/
    20. #include "main.h"
    21. #include "usart.h"
    22. #include "gpio.h"
    23. #include <string.h>
    25. #define RXBUFFERSIZE  256     //最大接收字节数
    26. char RxBuffer[RXBUFFERSIZE];   //接收数据
    27. uint8_t aRxBuffer;            //接收中断缓冲
    28. uint8_t Uart1_Rx_Cnt = 0;        //接收缓冲计数
    29. /* Private includes ----------------------------------------------------------*/
    30. /* USER CODE BEGIN Includes */
    32. /* USER CODE END Includes */
    34. /* Private typedef -----------------------------------------------------------*/
    35. /* USER CODE BEGIN PTD */
    37. /* USER CODE END PTD */
    39. /* Private define ------------------------------------------------------------*/
    40. /* USER CODE BEGIN PD */
    41. #define RXBUFFERSIZE  256
    42. char RxBuffer[RXBUFFERSIZE];
    43. /* USER CODE END PD */
    45. /* Private macro -------------------------------------------------------------*/
    46. /* USER CODE BEGIN PM */
    48. /* USER CODE END PM */
    50. /* Private variables ---------------------------------------------------------*/
    52. /* USER CODE BEGIN PV */
    54. /* USER CODE END PV */
    56. /* Private function prototypes -----------------------------------------------*/
    57. void SystemClock_Config(void);
    58. /* USER CODE BEGIN PFP */
    60. /* USER CODE END PFP */
    62. /* Private user code ---------------------------------------------------------*/
    63. /* USER CODE BEGIN 0 */
    65. /* USER CODE END 0 */
    67. /**
    68.   * @brief  The application entry point.
    69.   * @retval int
    70.   */
    71. int main(void)
    72. {
    73.   /* USER CODE BEGIN 1 */
    75.   /* USER CODE END 1 */
    77.   /* MCU Configuration--------------------------------------------------------*/
    79.   /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    80.   HAL_Init();
    82.   /* USER CODE BEGIN Init */
    84.   /* USER CODE END Init */
    86.   /* Configure the system clock */
    87.   SystemClock_Config();
    89.   /* USER CODE BEGIN SysInit */
    91.   /* USER CODE END SysInit */
    93.   /* Initialize all configured peripherals */
    94.   MX_GPIO_Init();
    95.   MX_USART1_UART_Init();
    96.   /* USER CODE BEGIN 2 */
    98.     HAL_UART_Receive_IT(&huart1, (uint8_t *)&aRxBuffer, 1);
    99.   /* USER CODE END 2 */
    101.   /* Infinite loop */
    102.   /* USER CODE BEGIN WHILE */
    103.   while (1)
    104.   {
    105.     /* USER CODE END WHILE */
    107.     /* USER CODE BEGIN 3 */
    114.   }
    115.   /* USER CODE END 3 */
    116. }
    118. /**
    119.   * @brief System Clock Configuration
    120.   * @retval None
    121.   */
    122. void SystemClock_Config(void)
    123. {
    124.   RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    125.   RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    127.   /** Configure the main internal regulator output voltage
    128.   */
    129.   __HAL_RCC_PWR_CLK_ENABLE();
    130.   __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
    132.   /** Initializes the RCC Oscillators according to the specified parameters
    133.   * in the RCC_OscInitTypeDef structure.
    134.   */
    135.   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
    136.   RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    137.   RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    138.   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    139.   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    140.   {
    141.     Error_Handler();
    142.   }
    144.   /** Initializes the CPU, AHB and APB buses clocks
    145.   */
    146.   RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
    147.                               |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
    148.   RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
    149.   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    150.   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    151.   RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    153.   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
    154.   {
    155.     Error_Handler();
    156.   }
    157. }
    159. /* USER CODE BEGIN 4 */
    164. /* USER CODE END 4 */
    166. /**
    167.   * @brief  This function is executed in case of error occurrence.
    168.   * @retval None
    169.   */
    170. void Error_Handler(void)
    171. {
    172.   /* USER CODE BEGIN Error_Handler_Debug */
    173.   /* User can add his own implementation to report the HAL error return state */
    174.   __disable_irq();
    175.   while (1)
    176.   {
    177.   }
    178.   /* USER CODE END Error_Handler_Debug */
    179. }
    181. #ifdef  USE_FULL_ASSERT
    182. /**
    183.   * @brief  Reports the name of the source file and the source line number
    184.   *         where the assert_param error has occurred.
    185.   * @param  file: pointer to the source file name
    186.   * @param  line: assert_param error line source number
    187.   * @retval None
    188.   */
    189. void assert_failed(uint8_t *file, uint32_t line)
    190. {
    191.   /* USER CODE BEGIN 6 */
    192.   /* User can add his own implementation to report the file name and line number,
    193.      ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
    194.   /* USER CODE END 6 */
    195. }
    196. #endif /* USE_FULL_ASSERT */
    197. /* USER CODE BEGIN 4 */
    199. void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
    200. {
    201.     /* Prevent unused argument(s) compilation warning */
    202.     UNUSED(huart);
    203.     /* NOTE: This function Should not be modified, when the callback is needed,
    204.              the HAL_UART_TxCpltCallback could be implemented in the user file
    205.      */
    207.     if(Uart1_Rx_Cnt >= 255)  //溢出判断
    208.     {
    209.         Uart1_Rx_Cnt = 0;
    210.         memset(RxBuffer,0x00,sizeof(RxBuffer));
    211.         HAL_UART_Transmit(&huart1, (uint8_t *)"数据溢出", 10,0xFFFF);
    213.     }
    214.     else
    215.     {
    216.         RxBuffer[Uart1_Rx_Cnt++] = aRxBuffer;   //接收数据转存
    218.         if((RxBuffer[Uart1_Rx_Cnt-1] == 0x0A)&&(RxBuffer[Uart1_Rx_Cnt-2] == 0x0D)) //判断结束位
    219.         {
    220.             HAL_UART_Transmit(&huart1, (uint8_t *)&RxBuffer, Uart1_Rx_Cnt,0xFFFF); //将收到的信息发送出去
    221.             while(HAL_UART_GetState(&huart1) == HAL_UART_STATE_BUSY_TX);//检测UART发送结束
    222.             Uart1_Rx_Cnt = 0;
    223.             memset(RxBuffer,0x00,sizeof(RxBuffer)); //清空数组
    224.         }
    225.     }
    227.     HAL_UART_Receive_IT(&huart1, (uint8_t *)&aRxBuffer, 1);   //再开启接收中断
    228. }
    229. /* USER CODE END 4 */