STM32外部中断设置

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http://www.cnblogs.com/zjgtan/archive/2013/02/23/2923482.html


硬件情况:采用PA11管脚

需要明确的是,PxN管脚共用外部中断线EXTIN和外部中断向量EXTIN_IRQn和中断服务程序入口EXTIN_IRQHandler,但是需要注意的是[9...5]共用EXTI9_5_IRQn和EXTI9_5_IRQHandler、[15...10]共用EXTI15_10_IRQn和EXTI15_10_IRQHandler

基本过程:

1、设置时钟

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RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);

 注意需要打开AFIO时钟

2、配置GPIO

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GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

采用模拟输入方式

3、将GPIO管脚与外部中断线连接

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GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource11);

  相当重要

4、配置EXTI

EXTI_InitStructure.EXTI_Line = EXTI_Line11;EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init(&EXTI_InitStructure);

包括触发方式等等

6、配置NVIC

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NVIC_InitTypeDef NVIC_InitStructure;   
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
 
NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;//PPP外部中断线
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

7、写中断服务程序

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void EXTI15_10_IRQHandler(void)
{
    if(EXTI_GetITStatus(EXTI_Line11) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line11);//清除标志
        ...
    }
}

  

另外,简单的滤波方法可以在主逻辑中实现

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