首先配置外部中断的输入引脚和中断源:
void LCR_Config(void)
{
EXTI_InitTypeDef EXTI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable GPIOC clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
/* Enable AFIO clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.e_GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.e_GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOC, &GPIO_InitStructure);
/* Connect EXTI8 Line to PC.08 pin */
GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource8);
/* Configure EXTI8 line */
EXTI_InitStructure.EXTI_Line = EXTI_Line8;
EXTI_InitStructure.e_EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.e_EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.e_EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitSt