GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;

这段代码是用来配置特定的GPIO管脚的中断模式的。具体来说，这里将GPIO_InitStruct的Mode成员设置为GPIO_MODE_IT_RISING，表示这个管脚上的中断将在上升沿触发。这意味着当这个管脚从低电平变为高电平时，将会触发一个中断。其他的中断模式包括GPIO_MODE_IT_FALLING（下降沿触发）、GPIO_MODE_IT_RISING_FALLING（上升沿和下降沿都触发）以及GPIO_MODE_EVT_RISING（外部事件模式，上升沿触发）等。

相关问题

void KEY_GPIO_CONFIG(void) { EXTI_InitTypeDef EXTI_InitStruct; NVIC_InitTypeDef NVIC_InitStruct; GPIO_InitTypeDef GPIO_InitStruct; RCC_APB2PeriphClockCmd(GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2,ENABLE); GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPD;// GPIO_Init(GPIOA,&GPIO_InitStruct); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource1); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource2); // 配置外部中断 EXTI_InitStruct.EXTI_Line = EXTI_Line0 | EXTI_Line1 | EXTI_Line2; EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Rising; EXTI_InitStruct.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStruct); // 配置中断向量表 NVIC_InitStruct.NVIC_IRQChannel = EXTI0_IRQn; NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1; NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStruct); NVIC_InitStruct.NVIC_IRQChannel = EXTI1_IRQn; NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1; NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStruct); NVIC_InitStruct.NVIC_IRQChannel = EXTI2_IRQn; NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1; NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStruct); } 为什么这样配置出来的代码，下载到单片机led灯电平会飘移

根据您提供的代码，有几个可能导致LED灯电平飘移的原因：

1. GPIO模式配置不正确：在`KEY_GPIO_CONFIG`函数中，您将GPIO的模式配置为`GPIO_Mode_IPD`，这意味着输入下拉模式。如果您希望通过按下按键来改变LED灯的状态，那么您应该将GPIO的模式配置为输出模式，例如`GPIO_Mode_Out_PP`或`GPIO_Mode_Out_OD`，以便控制LED灯的电平。

2. 外部中断配置不正确：在配置外部中断时，您将外部中断的触发方式配置为`EXTI_Trigger_Rising`，这意味着在检测到上升沿时触发中断。如果按键没有消除按下时的抖动，并且导致电平变化产生了上升沿和下降沿，那么就会触发多次中断，从而导致LED灯电平飘移。您可以尝试将触发方式配置为`EXTI_Trigger_Falling`，这样在下降沿时触发中断，以避免电平变化引起的抖动问题。

3. 中断优先级配置不正确：在配置中断优先级时，确保不同中断的优先级设置不同。如果多个中断具有相同的优先级，则可能会导致中断嵌套和电平飘移。请确保每个中断的优先级不同，例如使用`NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority`和`NVIC_InitStruct.NVIC_IRQChannelSubPriority`来设置不同的抢占优先级和子优先级。

请检查以上几个方面，并根据您的需求和实际硬件配置进行相应的修改和调试，以解决LED灯电平飘移的问题。

void Encoder_Init(void) { RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE); TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure; TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1; TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInitStructure.TIM_Period = 1000 - 1; TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1; TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0; TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStructure); TIM_ITConfig(TIM1, TIM_IT_Update, ENABLE); TIM_Cmd(TIM1, ENABLE); GPIO_InitTypeDef GPIO_InitStructure1; GPIO_InitStructure1.GPIO_Mode=GPIO_Mode_IPU; GPIO_InitStructure1.GPIO_Pin=GPIO_Pin_0|GPIO_Pin_1; GPIO_InitStructure1.GPIO_Speed=GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure1); GPIO_InitTypeDef GPIO_InitStructure2; GPIO_InitStructure2.GPIO_Mode=GPIO_Mode_IPU; GPIO_InitStructure2.GPIO_Pin=GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_10|GPIO_Pin_11|GPIO_Pin_12|GPIO_Pin_13; GPIO_InitStructure2.GPIO_Speed=GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitStructure2); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource1); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource4); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource5); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource10); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource11); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource12); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource13); EXTI_InitTypeDef EXTI_InitStructure; EXTI_InitStructure.EXTI_Line = EXTI_Line0|EXTI_Line1|EXTI_Line4|EXTI_Line5|EXTI_Line10|EXTI_Line11|EXTI_Line12|EXTI_Line13; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling; EXTI_Init(&EXTI_InitStructure); NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); NVIC_InitTypeDef NVIC_InitStruct1; NVIC_InitStruct1.NVIC_IRQChannel = EXTI0_IRQn; NVIC_InitStruct1.NVIC_IRQChannelCmd = ENABLE; NVIC_InitStruct1.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStruct1.NVIC_IRQChannelSubPriority = 0x00; NVIC_Init(&NVIC_InitStruct1); NVIC_InitTypeDef NVIC_InitStruct2; NVIC_InitStruct2.NVIC_IRQChannel = EXTI1_IRQn; NVIC_InitStruct2.NVIC_IRQChannelCmd = ENABLE; NVIC_InitStruct2.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStruct2.NVIC_IRQChannelSubPriority = 0x00; NVIC_Init(&NVIC_InitStruct2); NVIC_InitTypeDef NVIC_InitStruct3; NVIC_InitStruct3.NVIC_IRQChannel = EXTI4_IRQn; NVIC_InitStruct3.NVIC_IRQChannelCmd = ENABLE; NVIC_InitStruct3.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStruct3.NVIC_IRQChannelSubPriority = 0x00; NVIC_Init(&NVIC_InitStruct3); NVIC_InitTypeDef NVIC_InitStruct4; NVIC_InitStruct4.NVIC_IRQChannel = EXTI9_5_IRQn; NVIC_InitStruct4.NVIC_IRQChannelCmd = ENABLE; NVIC_InitStruct4.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStruct4.NVIC_IRQChannelSubPriority = 0x00; NVIC_Init(&NVIC_InitStruct4); NVIC_InitTypeDef NVIC_InitStruct5; NVIC_InitStruct5.NVIC_IRQChannel = EXTI15_10_IRQn; NVIC_InitStruct5.NVIC_IRQChannelCmd = ENABLE; NVIC_InitStruct5.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStruct5.NVIC_IRQChannelSubPriority = 0x00; NVIC_Init(&NVIC_InitStruct5); }stm32f103系列芯片，当这段代码初始化时，以PA2PA3初始化的串口不能正常工作，是为什么

这段代码中没有涉及到PA2和PA3，因此不太可能直接影响串口的正常工作。可能原因如下：

1. 可能是其他地方对PA2和PA3进行了配置，导致串口无法正常工作；
2. 可能是串口初始化代码存在问题，需要检查一下是否正确地配置了波特率、数据位、停止位等参数；
3. 可能是硬件问题，需要检查一下PA2和PA3的连接是否正确，是否存在短路等问题。