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 edgeEXTI_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 edgeEXTI_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);    }}

注:本文参考:http://www.61ic.com/Technology/embed/201103/31045.html

另一个示例:

配置如下:

void vcm_airbag_exti_set(void){    EXTI_InitTypeDef EXTI_InitStructure;NVIC_InitTypeDef NVIC_InitStructure;GPIO_InitTypeDef GPIO_InitStructure;/* Enable key GPIO clock */  RCC_AHB1PeriphClockCmd(AIRBAG_GPIO_RCC, ENABLE);GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;/* Configure  pin(PD_15): airbag gpio */    GPIO_InitStructure.GPIO_Pin = AIRBAG_GPIO_PIN;    GPIO_Init(AIRBAG_GPIO_PORT, &GPIO_InitStructure);RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); //´ò¿ªEXTIʱÖÓSYSCFG_EXTILineConfig(AIRBAG_EXTI_PORT, AIRBAG_EXTI_PIN);//ÉèÖÃPD15ΪEXTI    /* Configure  EXTI  *///EXTI_DeInit();    EXTI_InitStructure.EXTI_Line = AIRBAG_EXTI_LINE; //ÉèÖÃÒý½Å    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;//ÉèÖÃΪÍⲿÖжÏģʽ    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;  // ÉèÖÃÉÏÉýºÍϽµÑض¼¼ì²â    EXTI_InitStructure.EXTI_LineCmd = ENABLE; //ʹÄÜÍⲿÖжÏÐÂ״̬    EXTI_Init(&EXTI_InitStructure);   //¸ù¾ÝEXTI_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèEXTI¼Ä´æÆ÷  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;   //ʹÄÜÍⲿÖжÏͨµÀNVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F;  //ÏÈÕ¼ÓÅÏȼ¶4λ,¹²16¼¶NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F;  //ÏÈÕ¼ÓÅÏȼ¶0λ,´ÓÓÅÏȼ¶4λNVIC_Init(&NVIC_InitStructure);  //¸ù¾ÝNVIC_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèNVIC¼Ä´æÆ÷}

中断例程:

void EXTI15_10_IRQHandler(void){rt_interrupt_enter();/* °²È«ÆøÄÒÓ²Ïß¼ì²â´¦Àí¡¡*/vcm_airbag_exti_check();/* GPSÌìÏß¿ªÂ·¼ì²â´¦Àí¡¡*/gps_exti_check();rt_interrupt_leave();}

void vcm_airbag_exti_check(void){//¼ì²éµ±Ç°ÖжϵÄ״̬ÊÇ·ñºÏ·¨if(EXTI_GetITStatus(AIRBAG_EXTI_LINE) != RESET){//¶ÁÈ¡¹Ü½ÅµÄ״̬,ÕâÀï·µ»Ø0±íʾ°²È«ÆøÄÒ±¬¿ªif(0 ==GPIO_ReadInputDataBit(AIRBAG_GPIO_PORT,AIRBAG_GPIO_PIN)){ recv_frame.bus_type = BTYPE_HS_CAN;recv_frame.id = 0x545;recv_frame.data_buff[0] = 0x00;recv_frame.data_buff[1] = 0x01;recv_frame.data_buff[2] = 0x00;recv_frame.data_buff[3] = 0x00;recv_frame.data_buff[4] = 0x00;recv_frame.data_buff[5] = 0x00;recv_frame.data_buff[6] = 0x00;recv_frame.data_buff[7] = 0x00;VCM_DEBUG("[vcm] warning: airbag gpio interrupt rising.\r\n");}else{recv_frame.bus_type = BTYPE_HS_CAN;recv_frame.id = 0x545;recv_frame.data_buff[0] = 0x00;recv_frame.data_buff[1] = 0x00;recv_frame.data_buff[2] = 0x00;recv_frame.data_buff[3] = 0x00;recv_frame.data_buff[4] = 0x00;recv_frame.data_buff[5] = 0x00;recv_frame.data_buff[6] = 0x00;recv_frame.data_buff[7] = 0x00;VCM_DEBUG("[vcm] warning: airbag gpio interrupt falling.\r\n");}rt_mq_send(&recv_frame_mq,&recv_frame,sizeof(can_bus_frame));//ÇåÖжϱê־λEXTI_ClearITPendingBit(AIRBAG_EXTI_LINE);}}