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