<备战蓝桥杯之嵌入式>——EXTI

这次实验要实现的效果是通过中断方式按键控制LED闪烁翻转。

配置中断步骤是：

1：按键GPIO初始化；

2：使能AIFO时钟；

3：中断映射线配置；

4：EXTI配置；

5：NVIC配置；（主函数进行分组）

6：编写中断服务函数；

先贴出exti.c中的代码：

#include "exti.h"

#include "button.h"

#include "delay.h"

#include "led.h"

void MY_EXTI_Init(void)

{

EXTI_InitTypeDefEXTI_InitStructure;

NVIC_InitTypeDefNVIC_InitStructure;

Button_Init();

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOC,GPIO_PinSource5);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource15);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0);

EXTI_InitStructure.EXTI_Line=EXTI_Line5;

EXTI_InitStructure.EXTI_LineCmd=ENABLE;

EXTI_InitStructure.EXTI_Mode=EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Falling;

EXTI_Init(&EXTI_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel=EXTI9_5_IRQn;

NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority=2;

NVIC_Init(&NVIC_InitStructure);

EXTI_InitStructure.EXTI_Line=EXTI_Line15;

EXTI_InitStructure.EXTI_LineCmd=ENABLE;

EXTI_InitStructure.EXTI_Mode=EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Falling;

EXTI_Init(&EXTI_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel=EXTI15_10_IRQn;

NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;

NVIC_Init(&NVIC_InitStructure);

EXTI_InitStructure.EXTI_Line=EXTI_Line0;

EXTI_InitStructure.EXTI_LineCmd=ENABLE;

EXTI_InitStructure.EXTI_Mode=EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Rising;

EXTI_Init(&EXTI_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel=EXTI0_IRQn;

NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority=0;

NVIC_Init(&NVIC_InitStructure);

}

void EXTI9_5_IRQHandler(void)

{

delay_ms(10);

if(KEY0==0) GPIO_WriteBit(GPIOA,GPIO_Pin_8,(BitAction)(1-GPIO_ReadOutputDataBit(GPIOA,GPIO_Pin_8)));

EXTI_ClearITPendingBit(EXTI_Line5);

}

void EXTI15_10_IRQHandler(void)

{

delay_ms(10);

if(KEY1==0) GPIO_WriteBit(GPIOD,GPIO_Pin_2,(BitAction)(1-GPIO_ReadOutputDataBit(GPIOD,GPIO_Pin_2)));

EXTI_ClearITPendingBit(EXTI_Line15);

}

void EXTI0_IRQHandler(void)

{

delay_ms(10);

if(WK_UP==1)

{

GPIO_WriteBit(GPIOA,GPIO_Pin_8,(BitAction)(1-GPIO_ReadOutputDataBit(GPIOA,GPIO_Pin_8)));

GPIO_WriteBit(GPIOD,GPIO_Pin_2,(BitAction)(1-GPIO_ReadOutputDataBit(GPIOD,GPIO_Pin_2)));

}

EXTI_ClearITPendingBit(EXTI_Line0);

}

这里还有一点要说明的是GPIO_ReadOutputDataBit(GPIOA,GPIO_Pin_8)));可以轻松实现GPIO口状态翻转。

还有以下注意点：

1：NVIC函数在misc.h中，各通道在stm32f10x.h中，各中断函数名称在启动文件中

2：error: #268: declaration may not appear afterexecutable statement in block

在语句后不能再定义变量，比如 EXTI_InitTypeDefEXTI_InitStructure;这种语句应该放在最开头。

3：warning: #188-D: enumerated type mixed with anothertype 定义了枚举类型，却用其他类型向它赋值。

4：有多个中断时，NVIC_IRQChannelSubPriority响应优先级要有大小区分。这里所谓2位是指0到3。

5：注意触发方式是上升沿还是下降沿或者是双边沿。