stm32 application-simple serial port receiving and sending program

 Library version  : ST3.0.0

File: main.c

//Function: Initialize the serial port, turn on the timer interrupt, and then keep receiving data. Sending is implemented in the interrupt

#include "stm32f10x.h"
#include "usart.h"

u8 USART_rx_data;
int main(void)
{
  
  RCC_Configuration();      //System clock configuration
  GPIO_Configuration();      //Port initialization
  NVIC_Configuration();      //Interrupt source configuration
  USART_Configuration();     //Serial port 1 initialization
  Time_Init();            //Timer initialization
  #ifdef DEBUG
      debug();
  #endif
  TIM_Cmd(TIM3,ENABLE); 
  while(1)
  {

   }

}

File: usart.c

#include "stm32f10x.h"
#include "stdio.h"
#include "usart.h"
  unsigned char auchCRCHi [256] ={
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40,0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,
  0x00,0xC1,0x81,0x40,0x01,0xC0,0x80,0x41,0x01,0xC0,0x80,0x41,0x00,0xC1,0x81,0x40};
  unsigned char auchCRCLo [256] ={
  0x00,0xC0,0xC1,0x01,0xC3,0x03,0x02,0xC2,0xC6,0x06,0x07,0xC7,0x05,0xC5,0xC4,0x04,
  0xCC,0x0C,0x0D,0xCD,0x0F,0xCF,0xCE,0x0E,0x0A,0xCA,0xCB,0x0B,0xC9,0x09,0x08,0xC8,
  0xD8,0x18,0x19,0xD9,0x1B,0xDB,0xDA,0x1A,0x1E,0xDE,0xDF,0x1F,0xDD,0x1D,0x1C,0xDC,
  0x14,0xD4,0xD5,0x15,0xD7,0x17,0x16,0xD6,0xD2,0x12,0x13,0xD3,0x11,0xD1,0xD0,0x10,
  0xF0,0x30,0x31,0xF1,0x33,0xF3,0xF2,0x32,0x36,0xF6,0xF7,0x37,0xF5,0x35,0x34,0xF4,
  0x3C,0xFC,0xFD,0x3D,0xFF,0x3F,0x3E,0xFE,0xFA,0x3A,0x3B,0xFB,0x39,0xF9,0xF8,0x38,
  0x28,0xE8,0xE9,0x29,0xEB,0x2B,0x2A,0xEA,0xEE,0x2E,0x2F,0xEF,0x2D,0xED,0xEC,0x2C,
  0xE4,0x24,0x25,0xE5,0x27,0xE7,0xE6,0x26,0x22,0xE2,0xE3,0x23,0xE1,0x21,0x20,0xE0,
  0xA0,0x60,0x61,0xA1,0x63,0xA3,0xA2,0x62,0x66,0xA6,0xA7,0x67,0xA5,0x65,0x64,0xA4,
  0x6C,0xAC,0xAD,0x6D,0xAF,0x6F,0x6E,0xAE,0xAA,0x6A,0x6B,0xAB,0x69,0xA9,0xA8,0x68,
  0x78,0xB8,0xB9,0x79,0xBB,0x7B,0x7A,0xBA,0xBE,0x7E,0x7F,0xBF,0x7D,0xBD,0xBC,0x7C,
  0xB4,0x74,0x75,0xB5,0x77,0xB7,0xB6,0x76,0x72,0xB2,0xB3,0x73,0xB1,0x71,0x70,0xB0,
  0x50,0x90,0x91,0x51,0x93,0x53,0x52,0x92,0x96,0x56,0x57,0x97,0x55,0x95,0x94,0x54,
  0x9C,0x5C,0x5D,0x9D,0x5F,0x9F,0x9E,0x5E,0x5A,0x9A,0x9B,0x5B,0x99,0x59,0x58,0x98,
  0x88,0x48,0x49,0x89,0x4B,0x8B,0x8A,0x4A,0x4E,0x8E,0x8F,0x4F,0x8D,0x4D,0x4C,0x8C,
  0x44,0x84,0x85,0x45,0x87,0x47,0x46,0x86,0x82,0x42,0x43,0x83,0x41,0x81,0x80,0x40};

unsigned short CRC16(unsigned char* puchMsg, unsigned short usDataLen)
{

  unsigned char uchCRCHi = 0xFF ;
  unsigned char uchCRCLo = 0xFF ;
  unsigned char uIndex ;
  while (usDataLen--)
  {
    uIndex = uchCRCHi^*puchMsg++;
    uchCRCHi = uchCRCLo^auchCRCHi[uIndex];
    uchCRCLo = auchCRCLo[uIndex];
  }
  return (uchCRCHi << 8 | uchCRCLo) ;
}

void RCC_Configuration(void)
{
 ErrorStatus HSEStartUpStatus;       //Enumeration variable, define the start status of high-speed clock
 RCC_DeInit();                   //RCC system reset, for Debug purpose
 RCC_HSEConfig(RCC_HSE_ON);                 //Enable high-speed clock source HSE   
 HSEStartUpStatus = RCC_WaitForHSEStartUp();    //Wait for HSE to stabilize
 if(HSEStartUpStatus == SUCCESS)
 {
   FLASH_SetLatency(FLASH_Latency_2);      
 FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);      
   
   RCC_HCLKConfig(RCC_SYSCLK_Div1);         // HCLK = SYSCLK
   RCC_PCLK2Config(RCC_HCLK_Div1);          // PCLK2 = HCLK
   RCC_PCLK1Config(RCC_HCLK_Div2);         ///PCLK1 = HCLK/2
 
   RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);
   RCC_PLLCmd(ENABLE);
   while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET){}

   
   RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
   while(RCC_GetSYSCLKSource() != 0x08){}
 }
 RCC_APB2PeriphClockCmd( RCC_APB2Periph_USART1 |RCC_APB2Periph_GPIOA |RCC_APB2Periph_AFIO |RCC_APB2Periph_GPIOB , ENABLE);
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
}
//------------------------------------------------------------------
//Function name: void GPIO_Configuration()
//Input parameter: null
//Return parameter: null
//Description: GPIO initialization function
//------------------------------------------------------------------
void GPIO_Configuration(void)
{
 GPIO_InitTypeDef GPIO_InitStructure;      //GPIO initialization structure declaration
 
 
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;          //USART1 TX
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;    //Multiplexed push-pull output
 GPIO_InitStructure.GPIO_Speed ​​= GPIO_Speed_50MHz;   
 GPIO_Init(GPIOA, &GPIO_InitStructure);      //A port
 
 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;          //USART1 RX
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;   //Multiplexed floating input
 GPIO_Init(GPIOA, &GPIO_InitStructure);           //A port

 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; 
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;  
 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
 GPIO_Init(GPIOB, &GPIO_InitStructure);
}

//------------------------------------------------------------------
//Function name: void NVIC_Configuration()
//Input parameter: null
//Return parameter: null
//Description: NVIC initialization function
//------------------------------------------------------------------
void NVIC_Configuration(void)
{               
 NVIC_InitTypeDef NVIC_InitStructure;       //NVIC initialization structure declaration
 
 #ifdef VECT_TAB_RAM        
   
   NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); //If the program is debugged in RAM, then define the interrupt vector table in RAM, otherwise in Flash
 #else 
   
   NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);   
 #endif

   
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

  
 NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;          //Set serial port 1 interrupt
 NVIC_InitStructure.NVIC_IRQChannelPreemptionPrio rity = 0;         //Preempt priority 0
 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;     //Sub priority is 0
 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;      //Enable
 NVIC_Init(&NVIC_InitStructure);

 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;           //Set timer 3 global interrupt
 NVIC_InitStructure.NVIC_IRQChannelPreemptionPrio rity = 1;        //Preempt priority 1
 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;            //Sub priority is 0
 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;           //Enable
 NVIC_Init(&NVIC_InitStructure);
}
//------------------------------------------------------------------
//Function name: void USART_Configuration()
//Input parameter: null
//Return parameter: null
//Description: Serial port initialization function
//------------------------------------------------------------------
void USART_Configuration(void){
 USART_InitTypeDef USART_InitStructure;                   //Serial port initialization structure declaration
 USART_ClockInitTypeDef USART_ClockInitStruct;
 USART_InitStructure.USART_BaudRate = 115200;       //Set the baud rate to 115200bps
 USART_InitStructure.USART_WordLength = USART_WordLength_8b;   //Data bits 8 bits
 USART_InitStructure.USART_StopBits = USART_StopBits_1;    //Stop bit 1 bit
 USART_InitStructure.USART_Parity = USART_Parity_No;     //No parity bit
 USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;   //No hardware flow control
 USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;      //Both receive and transmit modes are turned on

 USART_ClockInitStruct.USART_Clock=USART_Clock_Disable;      //Serial port clock disabled
 USART_ClockInitStruct.USART_CPOL=USART_CPOL_Low;        //Data low level is valid
 USART_ClockInitStruct.USART_CPHA=USART_CPHA_2Edge;     //Configure CPHA so that data is captured at the second edge
 USART_ClockInitStruct.USART_LastBit=USART_LastBit_Disable;   // Disable the last bit so that the corresponding clock pulse will no longer be output to the SCLK pin
 USART_ClockInit(USART1, &USART_ClockInitStruct);       //Configure USART clock-related settings

 USART_Init(USART1, &USART_InitStructure);        //Configure serial port parameters function

 USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);       //Enable receive interrupt
//USART_ITConfig(USART1, USART_IT_TXE, ENABLE);     //Enable transmit buffer empty interrupt
//USART_ITConfig(USART1, USART_IT_TC, ENABLE);     //Enable transmit complete interrupt
 USART_ClearFlag(USART1,USART_FLAG_TC);         //Clear transmit complete flag
 USART_Cmd(USART1, ENABLE);          //Enable serial port 1
}[page]
//------------------------------------------------------------------
//Function name: void Time_Init()
//Input parameter: null
//Return parameter: null
//Description: Timer initialization function
//------------------------------------------------------------------
void Time_Init(void)
{
 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

 TIM_DeInit(TIM3);             //Reset TIM3
 timerTIM_TimeBaseStructure.TIM_Period = 7999;           //Set auto-reload register latch value, 1ms overflowTIM_TimeBaseStructure.TIM_Prescaler       
 = 8;       //9 divisionTIM_TimeBaseStructure.TIM_ClockDivision 
 = 0x0;       //Clock division            
 factorTIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //Counter up counting                      
  
 modeTIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);     //Write TIM3 register parameters

  TIM_ClearFlag(TIM3,TIM_FLAG_Update);

  TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE);

}

File: usart.h

#ifndef _USART_H
#define _USART_H

#include
#include "stm32f10x.h"

void RCC_Configuration(void);   //Declare RCC initialization function
void GPIO_Configuration(void);   //Declare GPIO initialization function
void NVIC_Configuration(void);   //Declare NVIC initialization function
void USART_Configuration(void);   //Declare serial port initialization function
void Time_Init(void);     //Declare timer initialization function
unsigned short CRC16(unsigned char* puchMsg, unsigned short usDataLen);

#endif

File: stm32f103x_it.c

//You need to set the serial port receiving interrupt and timer 3 interrupt, the interrupt time is 1ms

//------------------------------------------------------------------
//Function name: void USART1_IRQHandler(void)
//Input parameter: null
//Return parameter: null
//Description: Serial port receive interrupt service
//------------------------------------------------------------------
void USART1_IRQHandler(void)
{
  
  if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)          //Judge whether the read register is not empty
  {       
//     GPIO_SetBits(GPIOB,GPIO_Pin_6);
    rx_data[RbufCounter++]=USART_ReceiveData(USART1);   //Receive bytes to receive buffer
    if(USART_Rsv_Status==0)
    ​​{
      if(RbufCounter>1)
      {
        if(rx_data[0]==0xA5&&rx_data[1]==0x5A)    //When the first two bytes of the received data frame are 0xA5 and 0x5A at the same time
        {
          USART_Rsv_Status=1;
//            USART_SendData(USART1, rx_data[0]);
        }
        else
        {
          rx_data[0]=rx_data[1];
          RbufCounter=1;
         
        }
      }
    }
    else
    {
      USART_1ms_Cnt=0;
    }                
  }          
}
//------------------------------------------------------------------
//Function name: void TIM2_IRQHandler(void)
//Input parameter: null
//Return parameter: null
//Description: Timer 2 interrupt service
//------------------------------------------------------------------
void TIM2_IRQHandler(void)
{

}
//------------------------------------------------------------------
//Function name: void TIM3_IRQHandler(void)
//Input parameter: null
//Return parameter: null
//Description: Timer 3 interrupt service
//------------------------------------------------------------------
void TIM3_IRQHandler(void)
{ 

  if(TIM_GetITStatus(TIM3,TIM_IT_Update)!=RESET)        //Judge whether it is timer 3 overflow interrupt
  {
    
    GPIO_SetBits(GPIOB,GPIO_Pin_6);
    TIM_ClearITPendingBit(TIM3, TIM_IT_Update);   //Clear interrupt flag

    if(USART_Rsv_Status==1)
    USART_1ms_Cnt++;
    if(USART_1ms_Cnt>5)      
    {
//       USART_SendData(USART1,0xAA);
      USART_Rsv_Status=0;      //If the continuous count exceeds 5 times, set USART_Rsv_Status to 0 and continue to wait for reception
      USART_1ms_Cnt=0;         //When USART_1ms_Cnt>5, clear USART_1ms_Cnt 
      if(RbufCounter==(u16)rx_data[4]+7)              //Check data integrity
      {
        int i;     //Define loop variable
        int j;
        data_length=rx_data[4];
        for(i=0;i
        {
          data[i]=rx_data[i];
        } 
        CRC_data_Hi=rx_data[RbufCounter-1];
        CRC_data_Lo=rx_data[RbufCounter-2];
        CRC_data=CRC16((unsigned char*)data,data_length+5);
        CRC_data_Hi1=CRC_data>>8;
        CRC_data_Lo1=CRC_data&0x00ff;
         if(CRC_data_Hi==(u8)CRC_data_Hi1 && CRC_data_Lo==CRC_data_Lo1)
         {
           for(j=0;rx_data[j]!='';j++)   //Loop and output word by word until the end word ''
           {        
             USART_SendData(USART1, rx_data[j]);     //Send characters
             while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET)
             {
             } //Wait for the characters to be sent
           }
        }
      }
      RbufCounter=0;
    }      
  }
}