STM32 external interrupt Usage Summary

STM32 Interrupts are divided into external interrupts , Timer interrupt 、 Serial interrupt . Although the name is different , But the principles are the same , In this section, we will mainly introduce external interrupts and the writing of interrupt functions .

Follow the steps below to write functions and configure functions to complete the configuration of external interrupt functions .

First step ： To configure GPIO, Set to interrupt mode .

Second parts ： Configure interrupt function

            1、 Can make IO Port multiplexing function , Select the pin with interrupt .

            2、 Set external interrupt structure members .

            3、 Set interrupt priority .

            4、 Configure interrupt service function .

Example ： Interrupt function triggered by key

//GPIO  initialization 
void Init_LED(void)
{
GPIO_InitTypeDef GPIO_InitStructure;	// Define a GPIO Structural variable 

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE | RCC_APB2Periph_GPIOG, ENABLE);
// Enable each port clock ,
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14|GPIO_Pin_13;	// On board LED Number  D2、D5
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOG, &GPIO_InitStructure);

GPIO_Init(GPIOD, &GPIO_InitStructure);
}

 Interrupt function writing 

void Init_EXTIX_TI(void)
{

EXTI_InitTypeDef EXTI_InitStructure;	// Define a EXTI Structural variable 
NVIC_InitTypeDef NVIC_InitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);	// Can make IO Reuse function , It is important to use the interrupt function ！！！

/*  Pin selection  */
GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource13);// configure port C Of 13 The pin is the interrupt source 	 important ！！  On board label INT2
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource0); // configure port E Of 0 The pin is the interrupt source 	 important ！！  On board label INT1


/*  Set the members of the external interrupt structure */
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;	// The interrupt mode is interrupt mode 
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;	// Falling edge trigger 
EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line13;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;	// Enable medium break 
EXTI_Init(&EXTI_InitStructure);	// Initialize interrupt register according to parameters 
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);	// Set interrupt priority group 2

NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;	// Set the interrupt source as PC13
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;	// The priority of interrupts is 2
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;	// The sub-priority is 0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;	// To interrupt 
NVIC_Init(&NVIC_InitStructure);	// Initialize interrupt register according to parameters 

NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;	// Set the interrupt source as PE0
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;	// The priority of interrupts is 1
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;	// The sub-priority is 0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;	// To interrupt 
NVIC_Init(&NVIC_InitStructure);	// Initialize interrupt register according to parameters 

}

Finally, configure the interrupt service function （ Entry function 、 Interrupt handling function ）

The last step , It's also an important step , Configure interrupt service function , There are also entry functions . To put it bluntly , Is what you want your interrupt to do .

/*************************************************************
Be careful , The interrupt service procedure is simple , But when writing the entry function , Notice how the function name is written , Only as follows 3 There are two ways of naming .
（1）EXTI0_IRQHandler;EXTI Line 0
EXTI1_IRQHandler;EXTI Line 1
EXTI2_IRQHandler;EXTI Line 2
EXTI3_IRQHandler;EXTI Line 3
EXTI4_IRQHandler;EXTI Line 4
（2）
EXTI9_5_IRQHandler;EXTI Line 5-9
（3）
EXTI15_10_IRQHandler;EXTI Line 10-15

As long as it is a break line 5 The latter cannot be named like the first four , They have their own way .
************************************************************/

void EXTI15_10_IRQHandler(void) //pc13 Interrupt service routine , It is also an interrupt subfunction 
{
// There is usually a jitter elimination delay before the key is detected , Directly call the following delay function 

if(EXTI_GetITStatus(EXTI_Line13)!= RESET) // Determine whether an interruption has occurred , If it occurs, the interrupt flag is set to 1
{
//	LED1=0;

//	LED2=1;

GPIO_ResetBits(GPIOG, GPIO_Pin_14); //GPIOG Set to low level ,
GPIO_SetBits(GPIOD, GPIO_Pin_13); //GPIOD Set to high level , In fact, this part can also be written in the main function , stay while In that loop .

}

EXTI_ClearITPendingBit(EXTI_Line13);	// Use the library function to clear the interrupt flag bit , After entering the interrupt service program . The first is to clear the flag bit ,	
} // Otherwise he will not respond to the interruption , Do not enter interrupt function 

This is the entire external interrupt handler , Just draw the gourd and ladle directly .