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14
EXTI_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 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_2
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 header
uint16_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AFIO
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource14);
//配置EXTI 这里配置成上升沿触发中断，引脚为14
EXTI_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
