[STM32 learning] (6) use of serial port 1 (usart1)

SCM serial port must be learned , And it's important , It is very important in data transmission and program debugging .

This blog first learns USART1 A serial port

In fact, not every serial port IO Can be used as serial port , He is fixed IO Oral .

Such as USART1 Serial port corresponding to IO yes PA9、PA10, This is very important , Don't get it wrong . The material document is shown in the figure below ：

The model of single chip microcomputer I use here is STM32F103VET

The code is as follows ：

main.c

#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"

int main(void)
{		
	u8 t;
	u8 len;	
	u16 times=0;
	delay_init();	    	 // Delay function initialization 	  
	NVIC_Configuration(); 	 // Set up NVIC Interrupt grouping 2:2 Bit preemption priority ,2 Bit response priority 
	uart1_init(9600);	 // The serial port is initialized to 9600
	 
	//LED_Init();			     //LED Port initialization 
	//KEY_Init();          // Initialize the hardware interface connected with the key 
	//GPIO_Write(GPIOA,0X00F0);
	while(1)
	{
		if(USART_RX_STA&0x8000)
		{					   
			len=USART_RX_STA&0x3fff;// The length of data received this time 
			printf(" The message you sent is :\r\n");
			for(t=0;t<len;t++)
			{
				USART_SendData(USART1, USART_RX_BUF[t]);// Serial port 1 send data 
				while(USART_GetFlagStatus(USART1,USART_FLAG_TC)!=SET);// Wait for the end of sending 
			}
			printf("\r\n");// Insert newline 
			USART_RX_STA=0;
		}
		else
		{
			times++;
			if(times%5000==0)
			{
				printf("\r\n wan tin \r\n");
				printf("come on!! \r\n\r\n");
			}
			if(times%200==0)printf(" Please input data , End with enter \n");  
			if(times%30==0)LED1=!LED1;// flashing LED, Indicates that the system is running .
			delay_ms(10);   
		}
	}	 
}

usart.c

#include "sys.h"
#include "usart.h"	  

//	 

// 	  
 

//
// Add the following code , Support printf function , You don't need to choose use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
// Support functions required by the standard library                  
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
// Definition _sys_exit() To avoid using semi host mode     
void _sys_exit(int x) 
{ 
	x = x; 
} 
// redefinition fputc function  
int fputc(int ch, FILE *f)
{      
 	while(USART_GetFlagStatus(USART1,USART_FLAG_TC)==RESET); 
	USART_SendData(USART1,(uint8_t)ch);   
	
	return ch;
}
#endif 

/* Use microLib Methods */
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   // If enabled, receive 
// A serial port 1 Interrupt service routine 
// Be careful , Read USARTx->SR Can avoid inexplicable mistakes    	
u8 USART_RX_BUF[USART_REC_LEN];     // Receive buffer , Maximum USART_REC_LEN Bytes .
// Reception status 
//bit15,	 Receive completion flag 
//bit14,	 Received 0x0d
//bit13~0,	 Number of valid bytes received 
u16 USART_RX_STA=0;       // Receive status flag 	  

// initialization IO  A serial port 1 
//bound: Baud rate 
 void uart1_init(u32 bound){
     //GPIO Port settings 
     GPIO_InitTypeDef GPIO_InitStructure;
 	USART_InitTypeDef USART_InitStructure;
 	NVIC_InitTypeDef NVIC_InitStructure;
 	 
 	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	// Can make USART1,GPIOA The clock 
  	USART_DeInit(USART1);  // Reset serial port 1
 	 //USART1_TX   PA.9
     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
     GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	// Multiplexing push pull output 
     GPIO_Init(GPIOA, &GPIO_InitStructure); // initialization PA9
    
     //USART1_RX	  PA.10
     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;// Floating input 
     GPIO_Init(GPIOA, &GPIO_InitStructure);  // initialization PA10


    //USART  Initialize settings 

 	USART_InitStructure.USART_BaudRate = bound;// Generally set as 9600;
 	USART_InitStructure.USART_WordLength = USART_WordLength_8b;// The word is 8 Bit data format 
 	USART_InitStructure.USART_StopBits = USART_StopBits_1;// A stop bit 
 	USART_InitStructure.USART_Parity = USART_Parity_No;// No parity bit 
 	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;// No hardware data flow control 
 	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	// Transceiver mode 

     USART_Init(USART1, &USART_InitStructure); // Initialize serial port 
 #if EN_USART1_RX		  // If enabled, receive   
    //Usart1 NVIC  To configure 
     NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
 	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;// preemption 3
 	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		// Sub priority 3
 	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQ Channel enable 
 	NVIC_Init(&NVIC_InitStructure);	// Initialize... According to the specified parameters VIC register 
    
     USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);// Open interrupt 
 #endif
     USART_Cmd(USART1, ENABLE);                    // Enable serial port  

 }



 void USART1_IRQHandler(void)                	// A serial port 1 Interrupt service routine 
 	{
 	u8 Res;
 #ifdef OS_TICKS_PER_SEC	 	// If the number of clock beats is defined , Explain to use ucosII 了 .
 	OSIntEnter();    
 #endif
 	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  // Receive interrupt ( The data received must be 0x0d 0x0a ending )
 		{
 		Res =USART_ReceiveData(USART1);//(USART1->DR);	// Read received data 
 		
 		if((USART_RX_STA&0x8000)==0)// Reception is not complete 
 			{
 			if(USART_RX_STA&0x4000)// received 0x0d
 				{
 				if(Res!=0x0a)USART_RX_STA=0;// Receive error , restart 
 				else USART_RX_STA|=0x8000;	// The reception is complete  
 				}
 			else // I haven't received 0X0D
 				{	
 				if(Res==0x0d)USART_RX_STA|=0x4000;
 				else
 					{
 					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
 					USART_RX_STA++;
 					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;// Receiving data error , Start receiving again 	  
 					}		 
 				}
 			}   		 
      } 
 #ifdef OS_TICKS_PER_SEC	 	// If the number of clock beats is defined , Explain to use ucosII 了 .
 	OSIntExit();  											 
 #endif
 } 

#endif	

usart.h

#ifndef __USART_H
#define __USART_H
#include "stdio.h"	
#include "sys.h" 
//	 

// 	
#define USART_REC_LEN  			200  	// Define the maximum number of bytes received  200
#define EN_USART1_RX 			1		// Can make （1）/ prohibit （0） A serial port 1 receive 
	  	
extern u8  USART_RX_BUF[USART_REC_LEN]; // Receive buffer , Maximum USART_REC_LEN Bytes . The last byte is a newline character  
extern u16 USART_RX_STA;         		// Receive status flag 	
// If you want to interrupt the receiving serial port , Please do not comment on the following macro definition 
void uart1_init(u32 bound);
void uart2_init(u32 bound);
void uart3_init(u32 bound);
void uart4_init(u32 bound);
void uart5_init(u32 bound);
#endif

sys.c

#include "sys.h"


void NVIC_Configuration(void)
{

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);	// Set up NVIC Interrupt grouping 2:2 Bit preemption priority ,2 Bit response priority 

}

sys.h

#ifndef __SYS_H
#define __SYS_H	
#include "stm32f10x.h"
//	 

// 	 

//0, I won't support it ucos
//1, Support ucos
#define SYSTEM_SUPPORT_UCOS		0		// Define whether the system folder supports UCOS
																	    
	 
// Bit band operation , Realization 51 Allied GPIO Control function 
// The concrete realization idea , Reference resources <<CM3 Authoritative guide >> The fifth chapter (87 page ~92 page ).
//IO Port operation macro definition 
#define BITBAND(addr, bitnum) ((addr & 0xF0000000)+0x2000000+((addr &0xFFFFF)<<5)+(bitnum<<2)) 
#define MEM_ADDR(addr)  *((volatile unsigned long  *)(addr)) 
#define BIT_ADDR(addr, bitnum)   MEM_ADDR(BITBAND(addr, bitnum)) 
//IO Port address mapping 
#define GPIOA_ODR_Addr    (GPIOA_BASE+12) //0x4001080C 
#define GPIOB_ODR_Addr    (GPIOB_BASE+12) //0x40010C0C 
#define GPIOC_ODR_Addr    (GPIOC_BASE+12) //0x4001100C 
#define GPIOD_ODR_Addr    (GPIOD_BASE+12) //0x4001140C 
#define GPIOE_ODR_Addr    (GPIOE_BASE+12) //0x4001180C 
#define GPIOF_ODR_Addr    (GPIOF_BASE+12) //0x40011A0C    
#define GPIOG_ODR_Addr    (GPIOG_BASE+12) //0x40011E0C    

#define GPIOA_IDR_Addr    (GPIOA_BASE+8) //0x40010808 
#define GPIOB_IDR_Addr    (GPIOB_BASE+8) //0x40010C08 
#define GPIOC_IDR_Addr    (GPIOC_BASE+8) //0x40011008 
#define GPIOD_IDR_Addr    (GPIOD_BASE+8) //0x40011408 
#define GPIOE_IDR_Addr    (GPIOE_BASE+8) //0x40011808 
#define GPIOF_IDR_Addr    (GPIOF_BASE+8) //0x40011A08 
#define GPIOG_IDR_Addr    (GPIOG_BASE+8) //0x40011E08 
 
//IO Mouth operation , Only for single IO mouth !
// Make sure n The value is less than 16!
#define PAout(n)   BIT_ADDR(GPIOA_ODR_Addr,n)  // Output  
#define PAin(n)    BIT_ADDR(GPIOA_IDR_Addr,n)  // Input  

#define PBout(n)   BIT_ADDR(GPIOB_ODR_Addr,n)  // Output  
#define PBin(n)    BIT_ADDR(GPIOB_IDR_Addr,n)  // Input  

#define PCout(n)   BIT_ADDR(GPIOC_ODR_Addr,n)  // Output  
#define PCin(n)    BIT_ADDR(GPIOC_IDR_Addr,n)  // Input  

#define PDout(n)   BIT_ADDR(GPIOD_ODR_Addr,n)  // Output  
#define PDin(n)    BIT_ADDR(GPIOD_IDR_Addr,n)  // Input  

#define PEout(n)   BIT_ADDR(GPIOE_ODR_Addr,n)  // Output  
#define PEin(n)    BIT_ADDR(GPIOE_IDR_Addr,n)  // Input 

#define PFout(n)   BIT_ADDR(GPIOF_ODR_Addr,n)  // Output  
#define PFin(n)    BIT_ADDR(GPIOF_IDR_Addr,n)  // Input 

#define PGout(n)   BIT_ADDR(GPIOG_ODR_Addr,n)  // Output  
#define PGin(n)    BIT_ADDR(GPIOG_IDR_Addr,n)  // Input 



void NVIC_Configuration(void);



#endif

delay.c and delay.h The document is not provided here , Because there are few delay functions used in the serial port .

 

The effect is , What characters do you send to SCM , He will return you any character , Display in serial assistant .