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)
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);
/* 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