STM32中断触发

使用PB1作为外部中断触发，按一次按键灯处于亮状态，在按一次灯灭。

1、先配置GPIO端口、复用管脚外设时钟使能GPIO_Config();

void GPIO_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD,ENABLE);
    
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB,ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);//PB1复用管脚时钟使能
    
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12| GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;//配置推挽输出，灯太亮，刺眼，故意把配置OD门，亮度暗一点
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//由于配置OD输出，顾这要上拉
    GPIO_Init(GPIOD,&GPIO_InitStructure);
    
    //配置PB1管脚作为触发输入，因为PB1管脚直接接开关按钮到地，所以内部上拉让其管脚处于高电平状态，当开关按下时，PB1管脚被拉低，通过下降沿进行触发
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOB,&GPIO_InitStructure);
}

2、配置嵌套向量中断控制NVIC_Config（void），使用不同通道时得注意，EXTI0~EXTI4对应的是EXTI0_IRQn、EXTI1_IRQn、EXTI2_IRQn、EXTI3_IRQn和EXTI4_IRQn，EXTI5~EXTI9都用EXTI9_5_IRQn这个通道,EXTI10~EXTI15都用EXTI15_10_IRQn这个通道。

void NVIC_Config(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;
    
    #ifdef  VECT_TAB_RAM  
    /* Set the Vector Table base location at 0x20000000 */ 
    NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); 
    #else  /* VECT_TAB_FLASH  */
    /* Set the Vector Table base location at 0x08000000 */ 
    NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);   
    #endif
    
    NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn; //由于使用的是PB1，对应的是EXTI1通道
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //中断使能
    NVIC_Init(&NVIC_InitStructure);    
}

3、中断管脚配置EXTI_Config（void）

void EXTI_Config(void)
{
    EXTI_InitTypeDef EXTI_InitStructure;
    
    //PB1作为外部中断，得相连接
    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOB,EXTI_PinSource1);
    
    EXTI_InitStructure.EXTI_Line = EXTI_Line1;//通道
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;//中断
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;//下降沿
    EXTI_InitStructure.EXTI_LineCmd    = ENABLE;//使能
    EXTI_Init(&EXTI_InitStructure);
}

5、主函数调用上面几个函数

int main(void)
{
    Clock_Config();
    GPIO_Config();
    NVIC_Config();
    EXTI_Config();
        
  while (1)
  {
        
  }
}

6、找中断函数名，函数名都已固定好，可以到startup_stm32f2xx.s中查找相关中断函数名，这里用的是EXTI1_IRQHandler（）

__Vectors       DCD     __initial_sp               ; Top of Stack
                DCD     Reset_Handler              ; Reset Handler
                DCD     NMI_Handler                ; NMI Handler
                DCD     HardFault_Handler          ; Hard Fault Handler
                DCD     MemManage_Handler          ; MPU Fault Handler
                DCD     BusFault_Handler           ; Bus Fault Handler
                DCD     UsageFault_Handler         ; Usage Fault Handler
                DCD     0                          ; Reserved
                DCD     0                          ; Reserved
                DCD     0                          ; Reserved
                DCD     0                          ; Reserved
                DCD     SVC_Handler                ; SVCall Handler
                DCD     DebugMon_Handler           ; Debug Monitor Handler
                DCD     0                          ; Reserved
                DCD     PendSV_Handler             ; PendSV Handler
                DCD     SysTick_Handler            ; SysTick Handler

                ; External Interrupts
                DCD     WWDG_IRQHandler                   ; Window WatchDog                                        
                DCD     PVD_IRQHandler                    ; PVD through EXTI Line detection                        
                DCD     TAMP_STAMP_IRQHandler             ; Tamper and TimeStamps through the EXTI line            
                DCD     RTC_WKUP_IRQHandler               ; RTC Wakeup through the EXTI line                       
                DCD     FLASH_IRQHandler                  ; FLASH                                           
                DCD     RCC_IRQHandler                    ; RCC                                             
                DCD     EXTI0_IRQHandler                  ; EXTI Line0                                             
                DCD     EXTI1_IRQHandler                  ; EXTI Line1     //这里有，把EXTI1_IRQHandler 拷贝下来                                
                DCD     EXTI2_IRQHandler                  ; EXTI Line2                                             
                DCD     EXTI3_IRQHandler                  ; EXTI Line3                                             
                DCD     EXTI4_IRQHandler                  ; EXTI Line4   

7、写中断函数，把拷贝的函数名copy到stm32f2xx_it.c文件中的任意位置

int flag = 0;//定义全局变量
void EXTI1_IRQHandler()
{
    EXTI_ClearITPendingBit(EXTI_Line1); //清除中断挂起位，方便下次中断进入，因中断产生，该位会自动置位，所以这里得手动清除
    if(!flag)
    {
        flag = ~flag;
        GPIO_SetBits(GPIOD,GPIO_Pin_12);
        GPIO_SetBits(GPIOD,GPIO_Pin_13);
        GPIO_SetBits(GPIOD,GPIO_Pin_14);
        GPIO_SetBits(GPIOD,GPIO_Pin_15);
    }
    else
    {
        flag = ~flag;
        GPIO_ResetBits(GPIOD, GPIO_Pin_12);
        GPIO_ResetBits(GPIOD, GPIO_Pin_13);
        GPIO_ResetBits(GPIOD, GPIO_Pin_14);
        GPIO_ResetBits(GPIOD, GPIO_Pin_15);
    }    
}

OK，到此，中断处理函数就写好了，按一次按键灯处于亮状态，在按一次灯灭