STM32f1，输入信号（低电平）一旦加入外部中断反复进入

罗莎莉 · 发表于 2020-8-21 15:42:18

写了一段外部中断程序，用开发板测试进出中断正常，实际使用时，一上电（被检信号部分）反复进入中断。
下降沿触发中断，端口输入电平一直为低电平，代码如下，求分析原因

void ceshi_Init(void)
{
GPIO_InitTypeDef  GPIO_InitStructure;  //PB11
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void EXTIX_Init(void)
{
   EXTI_InitTypeDef EXTI_InitStructure;
   NVIC_InitTypeDef NVIC_InitStructure;
      ceshi_Init();
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);//外部中断，需要使能AFIO时钟

//PB11 中断线以及中断初始化配置
   GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource11);

   EXTI_InitStructure.EXTI_Line=EXTI_Line11;
   EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
   EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;//下降沿触发
   EXTI_InitStructure.EXTI_LineCmd = ENABLE;
   EXTI_Init(&EXTI_InitStructure);

//中断相关配置
      NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;
   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                               //使能外部中断通道
   NVIC_Init(&NVIC_InitStructure);
// EXTI_ClearITPendingBit(EXTI_Line11);
}
static u8 Photo_Cnt = 0;
u8 ReadIO = 0 ;
void EXTI15_10_IRQHandler(void)
{
delay_ms(10); //消抖
if(EXTI_GetITStatus(EXTI_Line11)!=RESET)
   {
      ReadIO =_GET_ReadIO_();
      if(ReadIO == 0x00)
      {
            Photo_Cnt++;
         if(Photo_Cnt != 3)
               printf("OK!\r\n");
         else
         {
               Photo_Cnt=0;
               LED0=!LED0;
         }
      }
EXTI_ClearITPendingBit(EXTI_Line11);
}
}