The MCU is very important for the debugging of the communication interface--uart

1, configuration steps in Cubemx

(1) RCC

Open HSE

Peripheral clock Configuration, HCLK = 72MHZ

(2) USART1

Asynchronous transceiver

Complete the above configuration to generate the code for the Keil project.

2,

Test procedures: In the Serial debugging assistant to send data to the UART1, using the method of interruption, stm32f103 received a string after entering the interrupt service function, and then write the received data like a serial port, displayed in the Serial debugging assistant.

(1) GPIO Init

void Hal_uart_mspinit (uart_handletypedef* huart)
{

  gpio_inittypedef gpio_initstruct;
  if (Huart->instance==usart1)
  {/
  * user code BEGIN usart1_mspinit 0 */

  * user code END usart1_mspinit 0 */
  /* Peripheral Clock Enable *
    /__hal_rcc_usart1_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);

  /* User code BEGIN usart1_mspinit 1 */

  * user code END usart1_mspinit 1 */
  }

(2) Main func

/** ****************************************************************************** * File name:main.c * D 
  Escription:main Program Body ****************************************************************************** * * COPYRIGHT (c) stmicroelectronics * * Redistribution and use of source and binary forms, with or without modif Ication, * is permitted provided that the following conditions is met: * 1. Redistributions of source code must retain the above copyright notice, * This list of conditions and the following
  Disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * This list of conditions and the FOLLOWI
  NG Disclaimer in the documentation * and/or and materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of its contributors * could be used to endorse or promote produc TS derived from this software * without specific Prior written permission. * * This software are provided by the COPYRIGHT holders and CONTRIBUTORS "as are" * and any EXPRESS OR implied warrantie
  S, including, but not LIMITED to, the * implied warranties of merchantability and FITNESS for A particular PURPOSE is * disclaimed. In NO EVENT shall the COPYRIGHT HOLDER OR CONTRIBUTORS is liable * for any DIRECT, INDIRECT, incidental, special, Exempl ARY, or consequential * damages (including, but not LIMITED to, procurement of substitute GOODS OR * SERVICES; LOSS of Use, DATA, OR profits;  or business interruption) however * caused and on any theory of liability, WHETHER in contract, STRICT liability, * OR TORT (including negligence OR OTHERWISE) arising in any-out-of-the----the-software, even IF advised of the P
  Ossibility of SUCH DAMAGE. * ****************************************************************************** */* Includes-------------------- ----------------------------------------------*/#iNclude "Main.h" #include "stm32f1xx_hal.h" #include "variable.h"/* user code BEGIN includes */* user code END includ

ES */* Private variables---------------------------------------------------------*/Uart_handletypedef Huart1; /* User code BEGIN PV */* Private Variables---------------------------------------------------------*/* User code EN
D PV */* Private function prototypes-----------------------------------------------*/void Systemclock_config (void);
void Error_Handler (void);
static void Mx_gpio_init (void);

static void Mx_usart1_uart_init (void); /* User code BEGIN PFP */* Private function Prototypes-----------------------------------------------*/* User code E
ND PFP */* User code BEGIN 0 */* user code END 0 */unsigned char uart_rx_buffer[20] = {0}; int main (void) {/* user code BEGIN 1 */* User code END 1 */* MCU Configuration------------------------------ ----------------------------*/* Reset of all peripherals, initializes theFlash interface and the Systick.

  */Hal_init ();

  /* Configure the system clock */Systemclock_config ();
  /* 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) {/*
USER CODE END while *///Hal_uart_transmit (&huart1, (uint8_t *) & "33\n", 3, 100);
  Hal_delay (50);
		/* USER CODE BEGIN 3 */hal_uart_receive_it (&huart1,uart_rx_buffer,4);

  Hal_delay (50); }/* USER CODE END 3 */}/** System Clock Configuration */void Systemclock_config (void) {Rcc_oscinittypedef rcc_
  Oscinitstruct;

    Rcc_clkinittypedef rcc_clkinitstruct;
  /**initializes the CPU, AHB and APB busses clocks */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 busses 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 ();

    }/**configure the Systick interrupt Time */Hal_systick_config (Hal_rcc_gethclkfreq ()/1000);

  /**configure the Systick */Hal_systick_clksourceconfig (SYSTICK_CLKSOURCE_HCLK); /* SYSTICK_IRQN Interrupt configuration */Hal_nviC_setpriority (systick_irqn, 0, 0); }/* USART1 init function */static void Mx_usart1_uart_init (void) {Huart1.
  Instance = USART1; Huart1.
  Init.baudrate = 9600; 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 ();
  } hal_nvic_setpriority (USART1_IRQN, 1, 1);  
  HAL_NVIC_ENABLEIRQ (USART1_IRQN); 
	__hal_uart_enable (&HUART1);

Hal_uart_receive_it (&huart1,uart_rx_buffer,4); } void Hal_uart_rxcpltcallback (Uart_handletypedef *uarthandle) {if (uart_rx_buffer[0] = = ' 0 ' && uart_rx_buff
		ER[3] = = ' 3 ') {Hal_uart_transmit (&huart1, (uint8_t *) &uart_rx_buffer[1], 2, 100);
	Hal_uart_transmit (&huart1, (uint8_t *) & "\ n", 1,100); }//hal_uart_receive_it (&huart1,uart_rx_buffer,4);
Hal_uart_transmit (&huart1, (uint8_t *) & "22\n", 3, 100); }/** Configure Pins as * Analog * Input * Output * event_out * exti * * STAT

IC void Mx_gpio_init (void) {/* GPIO Ports Clock Enable */__hal_rcc_gpioa_clk_enable ();
  }/* User code BEGIN 4 */* User code END 4 *//** * @brief This function is executed in case of error occurrence. * @param None * @retval none */void Error_Handler (void) {/* user CODE BEGIN Error_Handler */* user can add

His own implementation to report the HAL error return state */while (1) {}/* USER CODE END Error_Handler */} #ifdef Use_full_assert/** * @brief Reports The name of the source file and the source line number * where the
   Ert_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 p
Arameters value:file%s on line%d\r\n ", file, line) */*/* USER CODE END 6 */} #endif/** * @} *//** * @}
 *//************************ (C) COPYRIGHT STMicroelectronics *****end of file****/