STM32的外部中断配置及使用
配置1：GPIO；
配置外部中断为输入模式；
配置2：EXTI；
配置外部中断线和触发模式；
配置3：NVIC；
配置外部中断源和中断优先级；
需要注意的是：RCC_APB2Periph_AFIO 时钟必须打开，容易忽略的一点；
1 void EXTI_PORTC_CONFIG(void)
2 {
3 GPIO_InitTypeDef GPIO_InitStructure;
4 EXTI_InitTypeDef EXTI_InitStructure;
5 NVIC_InitTypeDef NVIC_InitStructure;
6
7 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC|RCC_APB2Periph_AFIO,ENABLE);
8
9 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
10 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU ; //内部上拉
11 GPIO_Init(GPIOC, &GPIO_InitStructure);
12
13 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
14 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU ; //内部上拉
15 GPIO_Init(GPIOC, &GPIO_InitStructure);
16
17 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
18 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU ; //内部上拉
19 GPIO_Init(GPIOC, &GPIO_InitStructure);
20
21 GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource2);
22 GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource3);
23 GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource5);
24
25 EXTI_InitStructure.EXTI_Line = EXTI_Line2;
26 EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
27 EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
28 EXTI_InitStructure.EXTI_LineCmd = ENABLE;
29 EXTI_Init(&EXTI_InitStructure);
30
31 EXTI_InitStructure.EXTI_Line = EXTI_Line3;
32 EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
33 EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
34 EXTI_InitStructure.EXTI_LineCmd = ENABLE;
35 EXTI_Init(&EXTI_InitStructure);
36
37 EXTI_InitStructure.EXTI_Line = EXTI_Line5;
38 EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
39 EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
40 EXTI_InitStructure.EXTI_LineCmd = ENABLE;
41 EXTI_Init(&EXTI_InitStructure);
42
43 NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
44 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
45 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
46 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
47 NVIC_Init(&NVIC_InitStructure);
48
49 NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
50 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
51 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
52 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
53 NVIC_Init(&NVIC_InitStructure);
54
55 NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
56 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
57 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
58 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
59 NVIC_Init(&NVIC_InitStructure);
60 }