Cubemx completes STM32F103 dual serial port 485 transceiver transmission

One 、 Hardware circuit

STM32F103EVT6 Basic circuit ; Select serial port 1、 A serial port 2; A serial port 2 adopt 485 Interface output , The control end is PC9 port ,PC9=1 Time to receive ,0 Time send .

Two 、CubeMX Complete the configuration , Build project

Configure clock 、 Debug mode 、IO、 A serial port 1、 A serial port 2 Parameters 、 Open the serial port interrupt .

3、 ... and 、Keil Add code , Complete the function

/* USER CODE BEGIN PV */

// Reception status , Completion flag is 1; In the receiving state, it is 0
uint8_t uart1Rxstate=0;
// Total number of bytes currently received
uint8_t uart1RxCounter=0;
// Receive buffer
uint8_t uart1RxBuff[128]={0};

//uart2 receive

// Reception status , Completion flag is 1; In the receiving state, it is 0
uint8_t uart2Rxstate=0;
// Total number of bytes currently received
uint8_t uart2RxCounter=0;
// Receive buffer
uint8_t uart2RxBuff[128]={0};

 void USER_UART2_IRQHandler(void);

/* 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 */
int fputc(int ch,FILE *f)
{
    HAL_UART_Transmit(&huart1,(uint8_t *)&ch,1,0xffff);
    return ch;
}
/* 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_TIM6_Init();
  MX_USART1_UART_Init();
  MX_USART2_UART_Init();
  /* USER CODE BEGIN 2 */
    
// Open serial port interrupt     
    __HAL_UART_ENABLE_IT(&huart1,UART_IT_RXNE);
    __HAL_UART_ENABLE_IT(&huart2,UART_IT_RXNE);    

// A serial port 2 485 Receive enable
    HAL_GPIO_WritePin(RS485_TX_EN_PORT, RS485_TX_EN_PIN, GPIO_PIN_RESET);

        printf("Test UART1 out Hello STM32!");
        char tr2[]="UART2 transmit sentence for test !";    
        HAL_Delay(500); 
        
        HAL_GPIO_WritePin(RS485_TX_EN_PORT, RS485_TX_EN_PIN, GPIO_PIN_SET);
        HAL_UART_Transmit(&huart2,(uint8_t *)&tr2,sizeof(tr2),0xffff);
        HAL_GPIO_WritePin(RS485_TX_EN_PORT, RS485_TX_EN_PIN, GPIO_PIN_RESET);
        HAL_Delay(500);         
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */

//         A serial port 1 Data received , A serial port 2 Output
        if(uart1Rxstate==1)
        {
            HAL_GPIO_WritePin(RS485_TX_EN_PORT, RS485_TX_EN_PIN, GPIO_PIN_SET);
            HAL_UART_Transmit(&huart2,(uint8_t *)&uart1RxBuff,uart1RxCounter,0xffff);
            HAL_GPIO_WritePin(RS485_TX_EN_PORT, RS485_TX_EN_PIN, GPIO_PIN_RESET);
            memset(uart1RxBuff,0,128);
            uart1Rxstate=0;
            uart1RxCounter=0;
        }
//         A serial port 2 Data received , A serial port 1 Output         
        if(uart2Rxstate==1)
        {
            HAL_UART_Transmit(&huart1,(uint8_t *)&uart2RxBuff,uart2RxCounter,0xffff);
            memset(uart2RxBuff,0,128);
            uart2Rxstate=0;
            uart2RxCounter=0;
        }        
        
  }
  /* USER CODE END 3 */
}

Four 、 Serial port debugging tool debugging test

Use the serial port debugging tool to debug .