2019年03月25日 | STM32之中断与事件---一个使用GPIO作为外部中断的示例

1.GPIO的正确设置

GPIO_InitTypeDef GPIO_InitStructure;

/* Enable GPIOD clock */

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);

/* Configure PD.03, PC.04, as input floating */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 ;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOD, GPIO_PinSource3); //PD3作为外部中断引脚

其中GPIO_EXITLineConfig函数的声明如下:

/**

* @brief Selects the GPIO pin used as EXTI Line.

* @param GPIO_PortSource: selects the GPIO port to be used as source for EXTI lines.

* This parameter can be GPIO_PortSourceGPIOx where x can be (A..G).

* @param GPIO_PinSource: specifies the EXTI line to be configured.

* This parameter can be GPIO_PinSourcex where x can be (0..15).

* @retval None

*/

void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource)

2.中断初始化

EXTI_InitTypeDef EXTI_InitStructure;

// Configure EXTI Line3 to generate an interrupt on falling edge

EXTI_InitStructure.EXTI_Line = EXTI_Line3;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOD, GPIO_PinSource4);

// Configure EXTI Line4 to generate an interrupt on falling edge

EXTI_InitStructure.EXTI_Line = EXTI_Line4;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

3.在NVIC_Configuration 中Configures the NVIC and Vector Table base address.

/* Configure the Priority Group to 2 bits */

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

/* enabling interrupt */

NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQChannel;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

/* Enable the EXTI3 Interrupt on PD.3 */

NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQChannel;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

/* Enable the EXTI4 Interrupt on PD.4 */

NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQChannel;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

4.在stm32f0x_it.c 中写入 中断处理函数

/*******************************************************************************

* Function Name : EXTI3_IRQHandler

* Description : This function handles External interrupt Line 3 request.

* Input : None

* Output : None

* Return : None

*******************************************************************************/

void EXTI3_IRQHandler(void)

{

    if(EXTI_GetITStatus(EXTI_Line3) != RESET)

    {

        // Led_RW_ON();

        GPIO_SetBits(GPIOC, GPIO_Pin_4| GPIO_Pin_5 );

        /* Clear the EXTI line 9 pending bit */

        EXTI_ClearITPendingBit(EXTI_Line3);

    }

}

/*******************************************************************************

* Function Name : EXTI4_IRQHandler

* Description : This function handles External interrupt Line 4 request.

* Input : None

* Output : None

* Return : None

*******************************************************************************/

void EXTI4_IRQHandler(void)

{

    if(EXTI_GetITStatus(EXTI_Line4) != RESET)

    {

        //Led_RW_OFF();

        GPIO_ResetBits(GPIOC, GPIO_Pin_4 | GPIO_Pin_5);

        /* Clear the EXTI line 9 pending bit */

        EXTI_ClearITPendingBit(EXTI_Line4);

    }

}