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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
