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