STM32 serial communication sending and receiving

There are pros and cons to using STM32. There are many types --- but there are too many types, and the information is also messy. In addition, when calling the library, I often forget to use some functions ------ such as the most commonly used serial port ------

-------------------------------------------------------------------------------USART ----Setup-------------------------------

void USART1_Config(void)
{
        GPIO_InitTypeDef GPIO_InitStructure;
        USART_InitTypeDef USART_InitStructure;

        RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE); //USART1--clock--corresponding--GPIO--clock on
 

 //USART1 Tx---GPIO----PA.09----Multiplexed push-pull output
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed ​​= GPIO_Speed_50MHz;
        GPIO_Init(GPIOA, &GPIO_InitStructure);

 //USART1 Rx---GPIO----PA.10----Floating input
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
        GPIO_Init(GPIOA, &GPIO_InitStructure);

 //USART1 mode configuration
        USART_InitStructure.USART_BaudRate = 115200; //Baud rateUSART_InitStructure.USART_WordLength
        = USART_WordLength_8b; //Word length of serial transmissionUSART_InitStructure.USART_StopBits =
        USART_StopBits_1; //Stop
        bitUSART_InitStructure.USART_Parity = USART_Parity_No ; //Parity bitUSART_InitStructure.USART_HardwareFlowControl
        = USART_HardwareFlowControl_None; //Hardware flow controlUSART_InitStructure.USART_Mode
        = USART_Mode_Rx | USART_Mode_Tx; //Serial port mode --- receive --- sendUSART_Init
        (USART1, &USART_InitStructure); 

        USART_ClearFlag(USART1,USART_FLAG_TC); //Clear serial port 1 send interrupt, otherwise the first number will not occur

        USART_ITConfig(USART1, USART_IT_RXNE, ENABLE); //Receive interrupt enable - usually used when an array is needed to save the received data in an interrupt

        USART_Cmd(USART1, ENABLE);//使能USART1
}

-----------------------------------------/Redirect C library function ----printf---- to USART1-----------------------------------

int fputc(int ch, FILE *f)
{
        USART_SendData(USART1, (uint8_t) ch); //Send one byte of data to USART1 
        while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET); //Wait for sending to complete

        return (ch);
}

-----------------------------------------/Redirect C library function ----scanf------ to USART1-----------------------
int fgetc(FILE *f)
{
        while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET); //Wait for serial port 1 to input data 
        return (int)USART_ReceiveData(USART1);
}

------The above two redirections----are to correspond the original C library functions to the current hardware---------

------We can also write similar functions ourselves--------Use the basic two functions----Send---USART_SendData()-----Receive------USART_ReceiveData()---

-----------------************************************************-------for example--------%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%-----

void MyPrintfByte(unsigned char byte) //Serial port sends a byte
{
        USART_SendData(USART1, byte); //Send data through library function
        while( USART_GetFlagStatus(USART1,USART_FLAG_TC)!= SET); //Wait for sending to complete, check if USART_FLAG_TC is set to 1       
}

---------------------------------------------
void MyPrintfStr(unsigned char *s) //Send string function--pointer--
{
        uint8_t i=0; //Define a local variable to send string++operationwhile

        (s[i]!='\0') //Each string ends with \0
        {
                USART_SendData(USART1,s[i]); //Send data through library functionwhile
                ( USART_GetFlagStatus(USART1,USART_FLAG_TC)!= SET); //Wait for sending to complete, check whether USART_FLAG_TC is set to 1
                 i++; //i++ once
        }
}

--------------------------------------------------
void MyPrintfArray(uint8_t send_array[],uint8_t num) //Two parameters, one is the array content, the other is the array length 1-255 
{
        uint8_t i=0; //Define a local variable to send the string++operationwhile

         (i        {
          USART_SendData(USART1,send_array[i]); //Send data through library functionwhile
         ( USART_GetFlagStatus(USART1,USART_FLAG_TC)!= SET); //Wait for sending to complete, check if USART_FLAG_TC is set to 1
          i++; //Add one         
        }        
}

-----------------------------------------An array needs to be defined in the main function-----to save the data received during the receive interrupt--------------------

uint8_t RS232_RX_BUF[24]; //array
uint8_t RS232_RX_CNT=0; //array real-time subscript

--------------------------When the time comes, directly judge or use the corresponding bit data in this array----------------------------------------

-----------------------------------------Interrupt--------Receive interrupt--------------------

----First declare that the receiving array is defined in the main function-----external variables----------------Pay special attention to the fact that values ​​cannot be assigned when declaring external variables-------------

extern uint8_t RS232_RX_BUF[24];
extern uint8_t RS232_RX_CNT;

-------------------------------------------Interrupt function---------------------------

void USART1_IRQHandler(void) 
{
        uint8_t res;         
        if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET) //Received data  
        {        
                res =USART_ReceiveData(USART1); //Read received data   
               RS232_RX_BUF[RS232_RX_CNT]=res; //Record received value 
   

   //USART_SendData(USART1, res);//Send data----echo

                RS232_RX_CNT++; //Receive data increases by 1  
                if( RS232_RX_CNT>23)
                        RS232_RX_CNT=0;    
        }
        if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET) 
        { 
                 USART_ClearITPendingBit(USART1, USART_IT_RXNE);//Clear the receive flag------need to be cleared each time the receive is completed
        }

}

----------------------------------------------------------Configure interrupt priority------------------------

static void NVIC_Configuration(void)
{
        NVIC_InitTypeDef NVIC_InitStructure;
  
        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);//interrupt group
  
        NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;//interrupt source
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;//preemption priority
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = ENABLE;
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//enable
        NVIC_Init(&NVIC_InitStructure);
}

---------------------------------------------------------------Configuration call in main function--------------------------

  USART1_Config(); //Serial port 1 is used to output debug information
  NVIC_Configuration();

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

 printf("The received data is %d \r\n",temp); 

【--------------------------------------------Final Summary------------------------------------------------】

1.GPIO and clock settings

2. Mode configuration selection -------Note to enable interrupt-----USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);

3. Writing interrupt functions

4. Setting interrupt priority

5. Main function call

------------------------------------------------------------------485 communication---same as ------------------