EXTI外部中断使用教程
首先先看下EXTI的框图
看这个框图就能知道要先初始化GPIO外设 那么和前面一样
1、先RCC使能时钟
2、配置GPIO 选择端口为输入模式，
3、配置AFIO，选择我们用的GPIO连接到后面的EXTI
4、配置EXTI，选择边沿触发方式 eg：上升沿 下降沿 双边沿。选择触发事件或者中断
5、配置NVIC，给中断配置优先级
AFIO函数
void GPIO_PinRemapConfig(uint32_t GPIO_Remap, FunctionalState NewState);
函数可以用来引脚重映射，参数1是要选择的重映射的方式，参数2是新的状态
void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource);
这个函数可以配置AFIO的数据选择器，来选择我们想要的中断引脚
EXTI配置
可以去exti的头文件的最下面 查看有什么函数 我们这里只用到了exti的初始化函数
void EXTI_DeInit(void);
void EXTI_Init(EXTI_InitTypeDef* EXTI_InitStruct);
void EXTI_StructInit(EXTI_InitTypeDef* EXTI_InitStruct);
void EXTI_GenerateSWInterrupt(uint32_t EXTI_Line);
FlagStatus EXTI_GetFlagStatus(uint32_t EXTI_Line);
void EXTI_ClearFlag(uint32_t EXTI_Line);
ITStatus EXTI_GetITStatus(uint32_t EXTI_Line);
void EXTI_ClearITPendingBit(uint32_t EXTI_Line);配置示范
//配置EXTI 这里配置成上升沿触发中断，引脚为14EXTI_InitTypeDef EXTI_InitStruct;EXTI_InitStruct.EXTI_Line = EXTI_Line14;EXTI_InitStruct.EXTI_LineCmd = ENABLE;EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Rising;EXTI_Init(&EXTI_InitStruct);NVIC配置
nvic的函数定义在misc.h里面
void NVIC_PriorityGroupConfig(uint32_t NVIC_PriorityGroup);
void NVIC_Init(NVIC_InitTypeDef* NVIC_InitStruct);
void NVIC_SetVectorTable(uint32_t NVIC_VectTab, uint32_t Offset);
void NVIC_SystemLPConfig(uint8_t LowPowerMode, FunctionalState NewState);
void SysTick_CLKSourceConfig(uint32_t SysTick_CLKSource);配置示范
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitTypeDef NVIC_InitStruct;NVIC_InitStruct.NVIC_IRQChannel = EXTI15_10_IRQn;NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStruct);中断函数
在Start\startup_stm32f10x_md.s里有汇编代码 能查看到每个模式下的中断函数
; External InterruptsDCD WWDG_IRQHandler ; Window WatchdogDCD PVD_IRQHandler ; PVD through EXTI Line detectDCD TAMPER_IRQHandler ; TamperDCD RTC_IRQHandler ; RTCDCD FLASH_IRQHandler ; FlashDCD RCC_IRQHandler ; RCCDCD EXTI0_IRQHandler ; EXTI Line 0DCD EXTI1_IRQHandler ; EXTI Line 1DCD EXTI2_IRQHandler ; EXTI Line 2DCD EXTI3_IRQHandler ; EXTI Line 3DCD EXTI4_IRQHandler ; EXTI Line 4DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7DCD ADC1_2_IRQHandler ; ADC1_2DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TXDCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0DCD CAN1_RX1_IRQHandler ; CAN1 RX1DCD CAN1_SCE_IRQHandler ; CAN1 SCEDCD EXTI9_5_IRQHandler ; EXTI Line 9..5DCD TIM1_BRK_IRQHandler ; TIM1 BreakDCD TIM1_UP_IRQHandler ; TIM1 UpdateDCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and CommutationDCD TIM1_CC_IRQHandler ; TIM1 Capture CompareDCD TIM2_IRQHandler ; TIM2DCD TIM3_IRQHandler ; TIM3DCD TIM4_IRQHandler ; TIM4DCD I2C1_EV_IRQHandler ; I2C1 EventDCD I2C1_ER_IRQHandler ; I2C1 ErrorDCD I2C2_EV_IRQHandler ; I2C2 EventDCD I2C2_ER_IRQHandler ; I2C2 ErrorDCD SPI1_IRQHandler ; SPI1DCD SPI2_IRQHandler ; SPI2DCD USART1_IRQHandler ; USART1DCD USART2_IRQHandler ; USART2DCD USART3_IRQHandler ; USART3DCD EXTI15_10_IRQHandler ; EXTI Line 15..10DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI LineDCD USBWakeUp_IRQHandler ; USB Wakeup from suspend这里我们用到的是14引脚 所以用这个中断函数
void EXTI15_10_IRQHandler(void)
{if (EXTI_GetITStatus(EXTI_Line14) == SET){COUNTSENSOR_COUNT++;EXTI_ClearITPendingBit(EXTI_Line14);}}下面是EXTI中断示范代码，头文件需要自己添加,能够实现计次加数
#include "stm32f10x.h" // Device headeruint16_t COUNTSENSOR_COUNT;
void CountSensor_Init(void)
{//使能GPIO和AFIO的时钟//EXTI和NVIC的时钟是一直打开的，所以不用使能，NVIC不归RCC管RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);GPIO_InitTypeDef GPIO_InitStruct;GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStruct.GPIO_Pin = GPIO_Pin_14;GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOB, &GPIO_InitStruct);//配置AFIOGPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource14);//配置EXTI 这里配置成上升沿触发中断，引脚为14EXTI_InitTypeDef EXTI_InitStruct;EXTI_InitStruct.EXTI_Line = EXTI_Line14;EXTI_InitStruct.EXTI_LineCmd = ENABLE;EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Rising;EXTI_Init(&EXTI_InitStruct);NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitTypeDef NVIC_InitStruct;NVIC_InitStruct.NVIC_IRQChannel = EXTI15_10_IRQn;NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStruct);
}uint16_t CountSensor_Get(void)
{return COUNTSENSOR_COUNT;
}
void EXTI15_10_IRQHandler(void)
{if (EXTI_GetITStatus(EXTI_Line14) == SET){COUNTSENSOR_COUNT++;EXTI_ClearITPendingBit(EXTI_Line14);}}
main.c
#include "stm32f10x.h" // Device header
#include "Delay.h"
#include "OLED.h"
#include "CountSensor.h"int main()
{OLED_Init();CountSensor_Init();OLED_ShowString(1, 1, "Count");while (1){OLED_ShowNum(1, 7, CountSensor_Get(), 5);}
}
总结
学好GPIO外设的使用方法 后面的这些外设使用起来都大差不差 而且ARM公司提供的库函数的函数注释也很详细 感觉最主要的就是要学会看框图 知道自己的工程需要哪些外设 然后他的电路图如何走 跟着一步步初始化和使能就可以
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