关于外部中断超声波测距，主程序的灯有延迟为什么会一直亮，数据还不停的发送

爱学拔 · 发表于 2017-7-13 16:05:22

主程序
while(1)
{

Wave_SRD_Strat();
      LED1=!LED1;
   delay_ms(3000);

}

下面的wave初始化程序
#define Trig GPIO_Pin_4

#define Echo GPIO_Pin_6

float Distance;

void Wave_SRD_Init(void)
{
GPIO_InitTypeDef  GPIO_InitSture;
EXTI_InitTypeDef  EXTI_InitSture;
NVIC_InitTypeDef  NVIC_InitSture;
//èç1ûía2¿ÖD¶ÏμÄ»°Ôòò»¶¨ê1ÄüAFIO¸′óÃ1|Äü
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO|RCC_APB2Periph_GPIOE,ENABLE);

//ÅäÖÃIO¶Ë¿ú
GPIO_InitSture.GPIO_Mode=GPIO_Mode_Out_PP; //íÆíìêä3öÄ￡ê½
GPIO_InitSture.GPIO_Pin=Trig;             //½&#171

E4óúTrigÏàá¬
GPIO_InitSture.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOE,&GPIO_InitSture);

GPIO_InitSture.GPIO_Mode=GPIO_Mode_IPD;    //à-êäèëÄ￡ê½
GPIO_InitSture.GPIO_Pin=Echo;             //½&#171

E6óúEchoÏàá¬
GPIO_InitSture.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(GPIOE,&GPIO_InitSture);

//ÖD¶Ïoí6¶Ë¿úó3éäò»Æe
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource6);

//ía2¿ÖD¶ÏÅäÖÃ
EXTI_InitSture.EXTI_Line=EXTI_Line6;
EXTI_InitSture.EXTI_LineCmd=ENABLE;
EXTI_InitSture.EXTI_Mode=EXTI_Mode_Interrupt;
EXTI_InitSture.EXTI_Trigger=EXTI_Trigger_Rising;
EXTI_Init(&EXTI_InitSture);

//ÖD¶ÏóÅÏè¼¶1üàí
NVIC_InitSture.NVIC_IRQChannel=EXTI9_5_IRQn;
NVIC_InitSture.NVIC_IRQChannelCmd=ENABLE;
NVIC_InitSture.NVIC_IRQChannelPreemptionPriority=2;
NVIC_InitSture.NVIC_IRQChannelSubPriority=2;
NVIC_Init(&NVIC_InitSture);
}

void EXTI9_5_IRQHandler(void)
{
delay_us(10);

if(EXTI_GetITStatus(EXTI_Line6)!=RESET)
{
TIM_SetCounter(TIM3,0);
TIM_Cmd(TIM3,ENABLE);

while(GPIO_ReadInputDataBit(GPIOE,Echo));  //μè′yμíμçÆ½

TIM_Cmd(TIM3,DISABLE);

Distance=TIM_GetCounter(TIM3)*340/200.0;

if(Distance>0)
{
printf("Distance:%f cm\r\n",Distance);
}

EXTI_ClearITPendingBit(EXTI_Line6);
}
}

void Wave_SRD_Strat(void)
{
GPIO_SetBits(GPIOE,Trig); //½«TrigéèÖÃÎa¸ßμçÆ½
delay_us(20);             //3ÖDø′óóú10us′￥·￠￡¬′￥·￠3¬éù2¨Ä￡¿é1¤×÷
GPIO_ResetBits(GPIOE,Trig);

}

虾兵蟹将 · 发表于 2017-7-13 16:05:23

爱学拔发表于 2017-7-13 20:10
有变化

我的理解是：超声波一直发送数据，表明程序一直进入中断，没办法执行LED控制的代码。具体原因我也不清楚，但你可以不采用外部中断的形式来读取超声波的数据，可以直接读取该引脚的电平，读到高电平开始计数，读到低电平结束计数，下面是我以前用过的代码，你可以参考一下
int GetDis(int echo,int trig)
{
  int dis;
int count;
GPIO_ResetBits(GPIOF,echo); //echo端口复位
GPIO_ResetBits(GPIOF,trig); //trig端口复位
  TIM_SetCounter(TIM4,0);    //TIM4计数值清零
GPIO_SetBits(GPIOF,trig);             //trig置高发出10us的高电平信号
delay_us(10);
GPIO_ResetBits(GPIOF,trig);
delay_us(100);
while(GPIO_ReadInputDataBit(GPIOF, echo) == 0);
TIM_Cmd(TIM4,ENABLE); //开启计数器
   //开启定时器开始计时
while(GPIO_ReadInputDataBit(GPIOF, echo)); //等待echo置低
TIM_Cmd(TIM4,DISABLE); //关闭计数器

count = TIM_GetCounter(TIM4);//获取计数器值
dis = (int)count/60.034;
return dis;
}