一、中断配置的步骤
1、使能中断
2、设置中断优先级分组
void NVIC_PriorityGroupConfig(uint32_tNVIC_PriorityGroup);
#define NVIC_PriorityGroup_0 ((uint32_t)0x700) /*0位抢占，4位响应 */ #define NVIC_PriorityGroup_1 ((uint32_t)0x600) /*1位抢占，3位响应 */ #define NVIC_PriorityGroup_2 ((uint32_t)0x500) /*2位抢占，2位响应 */ #define NVIC_PriorityGroup_3 ((uint32_t)0x400) /*3位抢占，1位响应 */ #define NVIC_PriorityGroup_4 ((uint32_t)0x300) /*4位抢占，0位响应 */ |
一般选择NVIC_PriorityGroup_2，即抢占和响应均有4级。
3、配置NVIC_InitTypeDef结构体
void NVIC_Init(NVIC_InitTypeDef*NVIC_InitStruct);
typedef struct { uint8_t NVIC_IRQChannel; /*指定要使能或要失能的IRQ通道，这个值可以从stm32f10x.h中引用*/ uint8_t NVIC_IRQChannelPreemptionPriority; /*指定抢占优先级，0-15 */ uint8_t NVIC_IRQChannelSubPriority; /*指定响应优先级，0-15 */ FunctionalState NVIC_IRQChannelCmd; /*使能或失能 ENABLE / DISABLE */ } NVIC_InitTypeDef; |
NVIC_IRQChannelPreemptionPriority和NVIC_IRQChannelSubPriority的取值范围与调用中断优先级分组函数NVIC_PriorityGroupConfig时的配置相关，如果分组选择的是NVIC_PriorityGroup_2，则这两个的取值均为0-3。
stm32f10x.h中定义的中断通道值(HD)：
typedef enum IRQn { /****** Cortex-M3 Processor Exceptions Numbers ************/ NonMaskableInt_IRQn = -14, /*!< 2 Non Maskable Interrupt */ MemoryManagement_IRQn = -12, /*!< 4 Cortex-M3 Memory Management Interrupt */ BusFault_IRQn = -11, /*!< 5 Cortex-M3 Bus Fault Interrupt */ UsageFault_IRQn = -10, /*!< 6 Cortex-M3 Usage Fault Interrupt */ SVCall_IRQn = -5, /*!< 11 Cortex-M3 SV Call Interrupt */ DebugMonitor_IRQn = -4, /*!< 12 Cortex-M3 Debug Monitor Interrupt */ PendSV_IRQn = -2, /*!< 14 Cortex-M3 Pend SV Interrupt */ SysTick_IRQn = -1, /*!< 15 Cortex-M3 System Tick Interrupt */ /****** STM32 specific Interrupt Numbers ***********************************/ WWDG_IRQn = 0, /*!< Window WatchDog Interrupt */ PVD_IRQn = 1, /*!< PVD through EXTI Line detection Interrupt */ TAMPER_IRQn = 2, /*!< Tamper Interrupt */ RTC_IRQn = 3, /*!< RTC global Interrupt */ FLASH_IRQn = 4, /*!< FLASH global Interrupt */ RCC_IRQn = 5, /*!< RCC global Interrupt */ EXTI0_IRQn = 6, /*!< EXTI Line0 Interrupt */ EXTI1_IRQn = 7, /*!< EXTI Line1 Interrupt */ EXTI2_IRQn = 8, /*!< EXTI Line2 Interrupt */ EXTI3_IRQn = 9, /*!< EXTI Line3 Interrupt */ EXTI4_IRQn = 10, /*!< EXTI Line4 Interrupt */ DMA1_Channel1_IRQn = 11, /*!< DMA1 Channel 1 global Interrupt */ DMA1_Channel2_IRQn = 12, /*!< DMA1 Channel 2 global Interrupt */ DMA1_Channel3_IRQn = 13, /*!< DMA1 Channel 3 global Interrupt */ DMA1_Channel4_IRQn = 14, /*!< DMA1 Channel 4 global Interrupt */ DMA1_Channel5_IRQn = 15, /*!< DMA1 Channel 5 global Interrupt */ DMA1_Channel6_IRQn = 16, /*!< DMA1 Channel 6 global Interrupt */ DMA1_Channel7_IRQn = 17, /*!< DMA1 Channel 7 global Interrupt */ #ifdef STM32F10X_HD ADC1_2_IRQn = 18, /* ADC1 and ADC2 global Interrupt */ USB_HP_CAN1_TX_IRQn = 19, /* USB Device High Priority or CAN1 TX Interrupts */ USB_LP_CAN1_RX0_IRQn = 20, /* USB Device Low Priority or CAN1 RX0 Interrupts */ CAN1_RX1_IRQn = 21, /* CAN1 RX1 Interrupt */ CAN1_SCE_IRQn = 22,/* CAN1 SCE Interrupt */ EXTI9_5_IRQn = 23, /* External Line[9:5] Interrupts */ TIM1_BRK_IRQn = 24, /* TIM1 Break Interrupt */ TIM1_UP_IRQn = 25, /* TIM1 Update Interrupt */ TIM1_TRG_COM_IRQn = 26, /* TIM1 Trigger and Commutation Interrupt */ TIM1_CC_IRQn = 27, /* TIM1 Capture Compare Interrupt */ TIM2_IRQn = 28, /* TIM2 global Interrupt */ TIM3_IRQn = 29, /* TIM3 global Interrupt */ TIM4_IRQn = 30, /* TIM4 global Interrupt */ I2C1_EV_IRQn = 31, /* I2C1 Event Interrupt */ I2C1_ER_IRQn = 32, /* I2C1 Error Interrupt */ I2C2_EV_IRQn = 33, /* I2C2 Event Interrupt */ I2C2_ER_IRQn = 34, /* I2C2 Error Interrupt */ SPI1_IRQn = 35, /* SPI1 global Interrupt */ SPI2_IRQn = 36, /* SPI2 global Interrupt */ USART1_IRQn = 37, /* USART1 global Interrupt */ USART2_IRQn = 38, /* USART2 global Interrupt */ USART3_IRQn = 39, /* USART3 global Interrupt */ EXTI15_10_IRQn = 40, /* External Line[15:10] Interrupts */ RTCAlarm_IRQn = 41, /* RTC Alarm through EXTI Line Interrupt */ USBWakeUp_IRQn = 42, /* USB Device WakeUp from suspend through EXTI Line Interrupt */ TIM8_BRK_IRQn = 43, /* TIM8 Break Interrupt */ TIM8_UP_IRQn = 44, /* TIM8 Update Interrupt */ TIM8_TRG_COM_IRQn = 45, /* TIM8 Trigger and Commutation Interrupt */ TIM8_CC_IRQn = 46, /* TIM8 Capture Compare Interrupt */ ADC3_IRQn = 47, /* ADC3 global Interrupt */ FSMC_IRQn = 48, /* FSMC global Interrupt */ SDIO_IRQn = 49, /* SDIO global Interrupt */ TIM5_IRQn = 50, /* TIM5 global Interrupt */ SPI3_IRQn = 51, /* SPI3 global Interrupt */ UART4_IRQn = 52, /* UART4 global Interrupt */ UART5_IRQn = 53, /* UART5 global Interrupt */ TIM6_IRQn = 54, /* TIM6 global Interrupt */ TIM7_IRQn = 55, /* TIM7 global Interrupt */ DMA2_Channel1_IRQn = 56, /* DMA2 Channel 1 global Interrupt */ DMA2_Channel2_IRQn = 57, /* DMA2 Channel 2 global Interrupt */ DMA2_Channel3_IRQn = 58, /* DMA2 Channel 3 global Interrupt */ DMA2_Channel4_5_IRQn = 59 /* DMA2 Channel 4 and Channel 5 global Interrupt */ } IRQn_Type; |
4、编写中断服务函数
中断服务函数有固定的函数名，在startup_stm32f10x_hd.s文件中已经定义：
__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 detect DCD TAMPER_IRQHandler ; Tamper DCD RTC_IRQHandler ; RTC DCD FLASH_IRQHandler ; Flash DCD RCC_IRQHandler ; RCC DCD EXTI0_IRQHandler ; EXTI Line 0 DCD EXTI1_IRQHandler ; EXTI Line 1 DCD EXTI2_IRQHandler ; EXTI Line 2 DCD EXTI3_IRQHandler ; EXTI Line 3 DCD EXTI4_IRQHandler ; EXTI Line 4 DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1 DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2 DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3 DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4 DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5 DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6 DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7 DCD ADC1_2_IRQHandler ; ADC1 & ADC2 DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TX DCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0 DCD CAN1_RX1_IRQHandler ; CAN1 RX1 DCD CAN1_SCE_IRQHandler ; CAN1 SCE DCD EXTI9_5_IRQHandler ; EXTI Line 9..5 DCD TIM1_BRK_IRQHandler ; TIM1 Break DCD TIM1_UP_IRQHandler ; TIM1 Update DCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and Commutation DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare DCD TIM2_IRQHandler ; TIM2 DCD TIM3_IRQHandler ; TIM3 DCD TIM4_IRQHandler ; TIM4 DCD I2C1_EV_IRQHandler ; I2C1 Event DCD I2C1_ER_IRQHandler ; I2C1 Error DCD I2C2_EV_IRQHandler ; I2C2 Event DCD I2C2_ER_IRQHandler ; I2C2 Error DCD SPI1_IRQHandler ; SPI1 DCD SPI2_IRQHandler ; SPI2 DCD USART1_IRQHandler ; USART1 DCD USART2_IRQHandler ; USART2 DCD USART3_IRQHandler ; USART3 DCD EXTI15_10_IRQHandler ; EXTI Line 15..10 DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI Line DCD USBWakeUp_IRQHandler ; USB Wakeup from suspend DCD TIM8_BRK_IRQHandler ; TIM8 Break DCD TIM8_UP_IRQHandler ; TIM8 Update DCD TIM8_TRG_COM_IRQHandler ; TIM8 Trigger and Commutation DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare DCD ADC3_IRQHandler ; ADC3 DCD FSMC_IRQHandler ; FSMC DCD SDIO_IRQHandler ; SDIO DCD TIM5_IRQHandler ; TIM5 DCD SPI3_IRQHandler ; SPI3 DCD UART4_IRQHandler ; UART4 DCD UART5_IRQHandler ; UART5 DCD TIM6_IRQHandler ; TIM6 DCD TIM7_IRQHandler ; TIM7 DCD DMA2_Channel1_IRQHandler ; DMA2 Channel1 DCD DMA2_Channel2_IRQHandler ; DMA2 Channel2 DCD DMA2_Channel3_IRQHandler ; DMA2 Channel3 DCD DMA2_Channel4_5_IRQHandler ; DMA2 Channel4 & Channel5 __Vectors_End |
二、外部中断/事件控制器EXTI
互联网型产品有20个EXTI，其他的有19个，与IO口引脚相连的有16个(EXTI0-EXTI15)，还有PVD(EXTI线16)，RTCAlarm(EXTI线17)，USB唤醒(EXTI线18)，以及互联网型的ETH_WKUP(EXTI线19)。EXTI0~EXTI15可以被映射到GPIOA-GPIOG的引脚上。
EXTI结构框图
三、外部中断配置
配置外部中断使用STM32外设库函数，涉及"stm32f10x_exti.h"、"stm32f10x_exti.c"、"stm32f10x_gpio.h"和"stm32f10x_gpio.c"四个文件。
在本程序中将开发板上的四个按键均配置为外部中断源，分别是GPIOA_0对应EXTI_Line0，GPIOE_2、GPIOE_3、和GPIOE_4分别对应EXTI_2、EXTI_3和EXTI_4。
1、使能IO口时钟，配置IO口为输入模式
2、开启AFIO时钟
RCC_APB2PeriphClockCmd( RCC_APB2Periph_AFIO, ENABLE );
3、设置IO口与中断线的映射关系
使用GPIO_EXTILineConfig函数("stm32f10x_gpio.h"和"stm32f10x_gpio.c")该函数原型为：void GPIO_EXTILineConfig( uint8_t GPIO_PortSource, uint8_t GPIO_PinSource);
其中GPIO_PortSource取值如下：
#define GPIO_PortSourceGPIOA ((uint8_t)0x00) #define GPIO_PortSourceGPIOB ((uint8_t)0x01) #define GPIO_PortSourceGPIOC ((uint8_t)0x02) #define GPIO_PortSourceGPIOD ((uint8_t)0x03) #define GPIO_PortSourceGPIOE ((uint8_t)0x04) #define GPIO_PortSourceGPIOF ((uint8_t)0x05) #define GPIO_PortSourceGPIOG ((uint8_t)0x06) |
GPIO_PinSource取值如下：
#define GPIO_PinSource0 ((uint8_t)0x00) #define GPIO_PinSource1 ((uint8_t)0x01) #define GPIO_PinSource2 ((uint8_t)0x02) #define GPIO_PinSource3 ((uint8_t)0x03) #define GPIO_PinSource4 ((uint8_t)0x04) #define GPIO_PinSource5 ((uint8_t)0x05) #define GPIO_PinSource6 ((uint8_t)0x06) #define GPIO_PinSource7 ((uint8_t)0x07) #define GPIO_PinSource8 ((uint8_t)0x08) #define GPIO_PinSource9 ((uint8_t)0x09) #define GPIO_PinSource10 ((uint8_t)0x0A) #define GPIO_PinSource11 ((uint8_t)0x0B) #define GPIO_PinSource12 ((uint8_t)0x0C) #define GPIO_PinSource13 ((uint8_t)0x0D) #define GPIO_PinSource14 ((uint8_t)0x0E) #define GPIO_PinSource15 ((uint8_t)0x0F) |
这里四个按键对应中断线映射：
GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0 );
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource2 );
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource3 );
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource4 );
4、配置中断分组(NVIC)，使能中断
voidNVIC_PriorityGroupConfig(uint32_t NVIC_PriorityGroup);
voidNVIC_Init(NVIC_InitTypeDef* NVIC_InitStruct);
这里如下调用：
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
//对GPIO_0，映射到EXTI0
NVIC_InitTypeDef NVIC_Struct;
NVIC_Stuct.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_Stuct.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_Stuct.NVIC_IRQChannelSubPriority = 3;
NVIC_Stuct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init( &NVIC_Struct );
5、初始化EXTI，选择触发方式
调用EXTI库函数EXTI_Init实现，该函数原型为：
voidEXTI_Init(EXTI_InitTypeDef* EXTI_InitStruct);
在"stm32f10x_exti.h"文件中定义了以下结构体和宏：
typedef struct { uint32_t EXTI_Line; /*指定要使能或失能的中断或事件线*/ EXTIMode_TypeDef EXTI_Mode; /*指定中断线的模式*/ EXTITrigger_TypeDef EXTI_Trigger; /*设置触发方式*/ FunctionalState EXTI_LineCmd; /*使能或失能 ENABLE or DISABLE */ }EXTI_InitTypeDef; #define EXTI_Line0 ((uint32_t)0x00001) /* External interrupt line 0 */ #define EXTI_Line1 ((uint32_t)0x00002) /* External interrupt line 1 */ #define EXTI_Line2 ((uint32_t)0x00004) /* External interrupt line 2 */ #define EXTI_Line3 ((uint32_t)0x00008) /* External interrupt line 3 */ #define EXTI_Line4 ((uint32_t)0x00010) /* External interrupt line 4 */ #define EXTI_Line5 ((uint32_t)0x00020) /* External interrupt line 5 */ #define EXTI_Line6 ((uint32_t)0x00040) /* External interrupt line 6 */ #define EXTI_Line7 ((uint32_t)0x00080) /* External interrupt line 7 */ #define EXTI_Line8 ((uint32_t)0x00100) /* External interrupt line 8 */ #define EXTI_Line9 ((uint32_t)0x00200) /* External interrupt line 9 */ #define EXTI_Line10 ((uint32_t)0x00400) /* External interrupt line 10 */ #define EXTI_Line11 ((uint32_t)0x00800) /* External interrupt line 11 */ #define EXTI_Line12 ((uint32_t)0x01000) /* External interrupt line 12 */ #define EXTI_Line13 ((uint32_t)0x02000) /* External interrupt line 13 */ #define EXTI_Line14 ((uint32_t)0x04000) /* External interrupt line 14 */ #define EXTI_Line15 ((uint32_t)0x08000) /* External interrupt line 15 */ #define EXTI_Line16 ((uint32_t)0x10000) /* External interrupt line 16 Connected to the PVD Output */ #define EXTI_Line17 ((uint32_t)0x20000) /* External interrupt line 17 Connected to the RTC Alarm event */ #define EXTI_Line18 ((uint32_t)0x40000) /* External interrupt line 18 Connected to the USB Device/USB OTG FS Wakeup from suspend event */ #define EXTI_Line19 ((uint32_t)0x80000) /* External interrupt line 19 Connected to the Ethernet Wakeup event */ typedef enum { EXTI_Mode_Interrupt = 0x00, //设置EXTI线路为中断请求 EXTI_Mode_Event = 0x04 //设置EXTI线路为事件请求 }EXTIMode_TypeDef; typedef enum { EXTI_Trigger_Rising = 0x08, //设置输入线路上升沿为中断请求 EXTI_Trigger_Falling = 0x0C, //设置输入线路下降沿为中断请求 EXTI_Trigger_Rising_Falling = 0x10 //设置输入线路上升沿和下降沿为中断请求 }EXTITrigger_TypeDef; |
这里分别对0,2,3,4四个外部中断进行设置：
对K_UP键中断设置，根据电路连接，因为该键设置为下拉方式，在没有按下时为低电平，按下时为高电平，所以应设为上升沿触发。
EXTI_InitTypeDef EXTI_Struct;
EXTI_Struct.EXTI_Line = EXTI_Line0;
EXTI_Struct.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_Struct.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_Struct.EXTI_LineCmd = ENABLE;
EXTI_Init( &EXTI_Struct );
另外3个类似操作。
6、设置中断处理函数
中断服务函数有固定的函数名，在startup_stm32f10x_hd.s文件中已经定义，这里的四个中断的函数名分别为：EXTI0_IRQHandler、EXTI2_IRQHandler、EXTI3_IRQHandler和EXTI4_IRQHandler。
void EXTI0_IRQHandler( void ) { if( EXTI_GetITStatus( EXTI_Line0 ) ==1) { delay_ms(10); if(K_UP==1) { Sound(262); } } EXTI_ClearITPendingBit( EXTI_Line0 ); } |
四、项目实现
1、本项目以使用STM32GPIO读取按键实现按键操作为基础(代码下载地址)。
2、由于本项目需要用到EXTI相关库函数，所以将"stm32f10x_exti.h"、"stm32f10x_exti.c"两个文件分别复制到项目文件夹的"Lib/inc"和"Lib/src"子文件夹下，并将"stm32f10x_exti.c"文件加入到项目的"Lib "组中。
3、在项目文件夹下的"User"子文件夹下新建"Exti"子文件夹，在Keil5中新建"Exti.h"和"Exti.c"文件，并将"Exti.c"文件加入到项目的"User "组中，然后修改"Include Paths"，添加".\User\Exti"路径，以便项目中其他程序能够引用"Exti.h"。
4、在"Exti.h"文件中添加相应的宏定义和函数声明，内容如下：
#ifndef __EXTI__H #define __EXTI__H #include "system.h" #include "stm32f10x_exti.h" void KEY_EXTI_Init(void); #endif |
5、在"Exti.c"文件中实现KEY_EXTI_Init函数和四个中断函数。
#include "exti.h" #include "key.h" #include "stm32f10x_rcc.h" #include "misc.h" #include "beep.h" #include "systick.h" void KEY_EXTI_Init(void) { NVIC_InitTypeDef NVIC_Struct; EXTI_InitTypeDef EXTI_Struct; //1、使能IO口时钟，配置IO口为输入模式 Key_Init(); //调用key.c中的初始化按键GPIO的函数 //2、开启AFIO时钟 RCC_APB2PeriphClockCmd( RCC_APB2Periph_AFIO, ENABLE ); //3、设置IO口与中断线的映射关系 GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0 ); GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource2 ); GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource3 ); GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource4 ); //4、配置中断分组(NVIC)，使能中断 NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2 );
NVIC_Struct.NVIC_IRQChannel = EXTI0_IRQn; NVIC_Struct.NVIC_IRQChannelPreemptionPriority = 2; NVIC_Struct.NVIC_IRQChannelSubPriority = 3; NVIC_Struct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init( &NVIC_Struct ); NVIC_Struct.NVIC_IRQChannel = EXTI2_IRQn; NVIC_Struct.NVIC_IRQChannelPreemptionPriority = 2; NVIC_Struct.NVIC_IRQChannelSubPriority = 3; NVIC_Struct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init( &NVIC_Struct ); NVIC_Struct.NVIC_IRQChannel = EXTI3_IRQn; NVIC_Struct.NVIC_IRQChannelPreemptionPriority = 2; NVIC_Struct.NVIC_IRQChannelSubPriority = 3; NVIC_Struct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init( &NVIC_Struct ); NVIC_Struct.NVIC_IRQChannel = EXTI4_IRQn; NVIC_Struct.NVIC_IRQChannelPreemptionPriority = 2; NVIC_Struct.NVIC_IRQChannelSubPriority = 3; NVIC_Struct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init( &NVIC_Struct ); //5、使能EXTI，选择触发方式 //K_UP设为上升沿触发 EXTI_Struct.EXTI_Line = EXTI_Line0; EXTI_Struct.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_Struct.EXTI_Trigger = EXTI_Trigger_Rising; EXTI_Struct.EXTI_LineCmd = ENABLE; EXTI_Init( &EXTI_Struct );
//K_LEFT,K_DOWN,K_RIGHT设为下降沿触发 EXTI_Struct.EXTI_Line = EXTI_Line2|EXTI_Line3|EXTI_Line4; EXTI_Struct.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_Struct.EXTI_Trigger = EXTI_Trigger_Rising; EXTI_Struct.EXTI_LineCmd = ENABLE; EXTI_Init( &EXTI_Struct ); } void EXTI0_IRQHandler(void) { u8 i; if( EXTI_GetITStatus( EXTI_Line0 ) == 1) { delay_ms(10); if(K_UP==1) { for(i=0; i<100;i++) Sound(262); } } EXTI_ClearITPendingBit(EXTI_Line0); } void EXTI2_IRQHandler(void) { u8 i; if( EXTI_GetITStatus( EXTI_Line2 ) == 1) { delay_ms(10); if(K_LEFT==0) { for(i=0; i<100;i++) Sound(294); } } EXTI_ClearITPendingBit(EXTI_Line2); } void EXTI3_IRQHandler(void) { u8 i; if( EXTI_GetITStatus( EXTI_Line3 ) == 1) { delay_ms(10); if(K_DOWN==0) { for(i=0; i<100;i++) Sound(330); } } EXTI_ClearITPendingBit(EXTI_Line3); } void EXTI4_IRQHandler(void) { u8 i; if( EXTI_GetITStatus( EXTI_Line4 ) == 1) { delay_ms(10); if(K_RIGHT==0) { for(i=0; i<100;i++) Sound(349); } } EXTI_ClearITPendingBit(EXTI_Line4); } |
6、修改"main.c"文件，内容如下：
#include "SysTick.h" #include "exti.h" #include "beep.h" int main() { SysTick_Init(72); BEEP_Init(); KEY_EXTI_Init(); while(1) { } } |
7、编译，下载到开发板