STM32 infrared communication

bsp_exti.c

#include "bsp_exti.h"

 static void NVIC_Configuration(void)  // Interrupt priority function 
{
    
  NVIC_InitTypeDef NVIC_InitStructure;
  
  /*  To configure NVIC For priority group 1 */
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);  // To configure NVIC For priority group 1
   
  NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn ;  // Configure interrupt sources ：
  /*EXTI0_IRQn/EXTI1_IRQn/ EXTI2_IRQn/EXTI3_IRQn/EXTI4_IRQn/EXTI9_5_IRQn/EXTI15_10_IRQn*/        
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;  // Configure preemption priority 
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;   // Configure sub priority 
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;   //   Enable interrupt channel 
  NVIC_Init(&NVIC_InitStructure);                // Write structure members 
  
}

void remote_EXTI_init(void)
{
    
  GPIO_InitTypeDef GPIO_InitStructure; //GPIO Structure 
	EXTI_InitTypeDef EXTI_InitStructure;  // Interrupt structure 

 	NVIC_Configuration();  // Interrupt priority function 

   // initialization GPIO
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE,ENABLE); // Turn on GPIO The clock of the port // Turn on the key GPIO The clock of the port 
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;  //  Which pin 
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  // Configure as floating input  
  GPIO_Init(GPIOE, &GPIO_InitStructure);  // Write structure GPIO member 

   // initialization EXTI
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); // Turn on reuse GPIO The clock of the port  // Turn on the key GPIO The clock of the port 
  GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource5); // choice EXTI The source of the signal GPIOE,pin5

  EXTI_InitStructure.EXTI_Line = EXTI_Line5; // Select interrupt source , Choose which pin 
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;  // Interrupt mode 
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling; // Both rising and falling edges trigger 
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;  // To interrupt 
  EXTI_Init(&EXTI_InitStructure);  // Write struct interrupt member 

	}
 Insert a code chip here 

remote.c

#include "remote.h"
#include "bsp_exti.h"

extern u32 count_100us;
u32	lt=0;  // Record the low level time 
u32	ht=0;  // Record the low level time 
u8	ind=0; // Record 32 A data code 
u8 	remotecode[4];  // Array to hold the address code , Address inversion , Data code , Data inversion 
u8	remotestat=0;		//0 Indicates that it is not decoded ,1 Indicates decoding ,2 Means to solve the code 
void	EXTI9_5_IRQHandler(void)  
{
    
	u8	triger;
	static	u8	dat,i,j;
	
	if(EXTI_GetITStatus(EXTI_Line5) != RESET) 
	{
    
		// Clears the interrupt flag bit 
		EXTI_ClearITPendingBit(EXTI_Line5); 
		triger=GPIO_ReadInputDataBit(GPIOE,GPIO_Pin_5);	// Read port level 
		// Rising edge 
		if(triger==1)
		{
    
			lt=count_100us; // Capture rising edge time 
			count_100us=0;
		}	
		// Falling edge 
		else
		{
    
			ht=count_100us;	 // Capture falling edge time 
			count_100us=0;
			

			//========================= decode ===========================//
			// Judge whether the leading code has come 
			if(remotestat==0)
			{
    
				if((lt<100)&&(lt>80)&&(ht<50)&&(ht>40))  // Determine whether the preamble is correct 
				{
    
					remotecode[0]=remotecode[1]=remotecode[2]=remotecode[3]=0;  // Address code , Address inversion , Data code , Data inversion   Starting from scratch 
					ind=i=0;  
					remotestat=1;// The preamble correctly enters the decoding -- Decode data code 
				}
			}
			else if(remotestat==1)  // The preamble correctly enters the decoding -- Decode data code 
			{
    
				j=ind>>3;//j=ind/8;// The first ind A size    Put in the... Of the array j In a byte 

				if((lt<8)&&(lt>4)&&(ht<7)&&(ht>3)){
    remotecode[j]|=0x00;}  // If low is 600us, Gao Shi 500us, Express 0
				else if((lt<8)&&(lt>4)&&(ht<18)&&(ht>14)){
    remotecode[j]|=0x80;} // If low is 600us, Gao Shi 1600us, Express 1
				else{
    remotestat=0;return;}  // Otherwise, decoding fails , sign out 
				
				ind++;  // Record how many high and low levels 
				i++;	// Record my remotecode[j] How many times 
				if(i!=8){
    remotecode[j]>>=1;}  // Every move 8 Save one bit array at a time 
				else{
    i=0;}
				if(ind>=32) // All in all 32 High and low levels 
				{
    
					ind=0;
					if((remotecode[2]+remotecode[3])==0xff)  // Judge whether the positive and negative data codes are correct 
					{
    
						remotestat=2;  // Correct, then enter the function we want to implement 
					}
					else
					{
    
						remotestat=0; // Otherwise, if the data code is incorrect , sign out 
					}
				}
			}
		}
	}  
}