STM32 external interrupt experiment

One 、 Reference material

Two 、 Overview of external interrupts

interrupt 1-4 There is a separate interrupt service function .

interrupt 5-9 Share an interrupt service function .

interrupt 10-15 Share an interrupt service function .

The interrupt service function is in startup_stm32f10x_hs.s Find .

 

3、 ... and 、 Common library functions for external interrupts

 

 

Four 、 General configuration steps for external interrupts

 

 1、 initialization IO The mouth is the input

because KEY0、KEY1、KEY2、KEY3 Ground so use pull-up input , Release the key to high level , Press the key for low level .

So trigger with falling edge .

KEY_UP contrary , Connected to high level , Use the drop-down to enter . Release the key to low level , Press the key to high level ,

So trigger with rising edge .

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE,ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
	
	GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPU;
	GPIO_InitStructure.GPIO_Pin=GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4;
	//GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
	GPIO_Init(GPIOE,&GPIO_InitStructure);
	GPIO_SetBits(GPIOE,GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4);	

	GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IPD;
	GPIO_InitStructure.GPIO_Pin=GPIO_Pin_0;
	//GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
	GPIO_Init(GPIOA,&GPIO_InitStructure);
	GPIO_ResetBits(GPIOA,GPIO_Pin_0);	

2、 Turn on IO Port multiplex clock

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);  // Can make AFIO The clock , This is the premise of calling external interrupts 

3、 Set up IO Mapping relationship between port and interrupt line

GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource4);  // hold PE4 and EXTI4 It maps 

4、 Initialize online interrupt , Set trigger conditions

EXTI_InitTypeDef EXTI_InitStruct;

EXTI_InitStruct.EXTI_Line = EXTI_Line4;
EXTI_InitStruct.EXTI_LineCmd = ENABLE; 
EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_Init(&EXTI_InitStruct);

5、 Configure interrupt grouping , And can interrupt

among ,EXTI4_IRQn from stm32f10x.h Inside looking for .

NVIC_InitTypeDef NVIC_InitStruct;

NVIC_InitStruct.NVIC_IRQChannel = EXTI4_IRQn;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 2; 
NVIC_InitStruct.NVIC_IRQChannelSubPriority = 2;
NVIC_Init(&NVIC_InitStruct);

6、 Write interrupt service function 、 Clears the interrupt flag bit

Interrupt service function EXTI4_IRQHandler It's defined , stay startup_stm32f10x_hs.s Find .

void EXTI4_IRQHandler(void)
{
	delay_ms(10);
	if(KEY3==0)
	{
		LED0=!LED0;
		LED1=!LED1;
	}
	EXTI_ClearITPendingBit(EXTI_Line4);
}

7、 stay exti.c Integrated inside

#include "stm32f10x.h"
#include "delay.h"
#include "key.h"
#include "led.h"
#include "beep.h"
#include "exti.h"

void exti_Init(void)
{
	EXTI_InitTypeDef EXTI_InitStruct;
	NVIC_InitTypeDef NVIC_InitStruct;
	
	void key_init();  //GPIO Initialize as input , and key_init() equally                               
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);         // Can make AFIO The clock , This is the premise of calling external interrupts 
	
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource4);  // hold PE4 and EXTI4 It maps 
	
	EXTI_InitStruct.EXTI_Line = EXTI_Line4;
	EXTI_InitStruct.EXTI_LineCmd = ENABLE; 
	EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_Init(&EXTI_InitStruct);
	
	NVIC_InitStruct.NVIC_IRQChannel = EXTI4_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 2; 
	NVIC_InitStruct.NVIC_IRQChannelSubPriority = 2;
	NVIC_Init(&NVIC_InitStruct);
}


void EXTI4_IRQHandler(void)
{
	delay_ms(10);
	if(KEY3==0)
	{
		LED0=!LED0;
		LED1=!LED1;
	}
	EXTI_ClearITPendingBit(EXTI_Line4);
}

8、exti.h

#ifndef __EXTI__H
#define __EXTI__H
#include "sys.h"

void exti_Init(void);

#endif

9、main.c

#include "stm32f10x.h"
#include "delay.h"
#include "exti.h"
#include "led.h"
#include "beep.h"
#include "key.h"
#include "usart.h"

 int main(void)
 {	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	delay_init();
	led_init();
	beep_init();
	key_init();
	exti_Init();
	uart_init(115200);
	LED0 = 0;
	while(1)
	{
		printf("OK\r\n");
		delay_ms(10);
	}
 }