STM32学习历程（day6）

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);}
}