stm32单片机个人学习笔记6（EXTI外部中断）

前言

本篇文章属于stm32 单片机（以下简称单片机）的学习笔记，来源于B站教学视频。下面是这位up主的视频链接。本文为个人学习笔记，只能做参考，细节方面建议观看视频，肯定受益匪浅。

STM32入门教程-2023版细致讲解中文字幕_哔哩哔哩_bilibili

一、 stm32中断

二、NVIC基本结构

三、NVIC优先级分组

四、EXTI简介

五、EXTI基本结构

六、AFIO复用IO口

七、EXTI框图

八、旋转编码器介绍

不同方向转动编码器会产生如下波形

九、实例一（对射式红外传感器计次）

1. 写初始化函数

（1）配置时钟（GPIO口和AFIO口的）（EXTI和NVIC的时钟自动是开启的，其中因为NVIC是内核的外设，RCC管的是内核外的外设）

（2）配置GPIO口

（3）配置AFIO外部中断引脚选择

（4）配置EXTI，EXTI初始化

（5）配置NVIC

2.中断函数

去启动文件找中断函数的函数名

CountSensor.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"uint16_t CountSensor_Count;void CountSensor_Init(void)
{//开启时钟RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);//配置GPIO口GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOB, &GPIO_InitStructure);//配置AFIO外部中断引脚选择GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource14);//配置EXTIEXTI_InitTypeDef EXTI_InitStructure;EXTI_InitStructure.EXTI_Line = EXTI_Line14;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;//不遮挡时，灯亮，发送0；遮挡时，灯灭，发送1EXTI_Init(&EXTI_InitStructure);//配置NVICNVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitTypeDef NVIC_InitStructure;NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStructure);
}uint16_t CountSensor_Get(void)
{return CountSensor_Count;
}void EXTI15_10_IRQHandler(void)
{if (EXTI_GetITStatus(EXTI_Line14) == SET){Delay_ms(500);CountSensor_Count++;EXTI_ClearITPendingBit(EXTI_Line14);}
}

十、实例二（旋转编码器计次）

1. 写初始化函数

同上

2.两个中断函数来判断旋转的方向

Encoder.c

#include "stm32f10x.h"                  // Device headerint16_t Encoder_Count;/*** @brief  旋转编码器初始化* @param  无* @retval 无*/
void Encoder_Init(void)
{//开启时钟RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);//配置GPIO口GPIO_InitTypeDef GPIO_InitStructure;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOB, &GPIO_InitStructure);//配置AFIO外部中断引脚选择GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource0);GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource1);//配置EXTIEXTI_InitTypeDef EXTI_InitStructure;EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;EXTI_Init(&EXTI_InitStructure);//配置NVICNVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitTypeDef NVIC_InitStructure;NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStructure);NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;NVIC_Init(&NVIC_InitStructure);
}/*** @brief  获取计数值* @param  无* @retval Temp，计数值*/
int16_t Encoder_Get(void)
{int16_t Temp;Temp = Encoder_Count;Encoder_Count = 0;return Temp;
}/*** @brief  PB0口中断函数* @param  无* @retval 无*/
void EXTI0_IRQHandler(void)
{if (EXTI_GetITStatus(EXTI_Line0) == SET){if (GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_1)==0){Encoder_Count--;}EXTI_ClearITPendingBit(EXTI_Line0);}
}/*** @brief  PB1口中断函数* @param  无* @retval 无*/
void EXTI1_IRQHandler(void)
{if (EXTI_GetITStatus(EXTI_Line1) == SET){if (GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_0)==0){Encoder_Count++;}EXTI_ClearITPendingBit(EXTI_Line1);}
}