求输入捕获的程序

李达达帝 · 发表于 2013-9-2 22:17:23

最近想调输入捕获给频率在一定范围内变化的方波想测试方波的频率有人写过吗求参考谢谢啊

正点原子 · 发表于 2013-9-2 22:36:38

输入捕获程序我们有例程，不过是检测高电平脉宽的，你稍微改下，就可以测量频率了。

李达达帝 · 发表于 2013-9-3 09:47:44

回复【2楼】正点原子:
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战舰的板子是借的学长的、、、原子哥你看下我这配置进入中断后一直出不来
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);//开启时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

GPIO_InitStructure.GPIO_Pin =GPIO_Pin_3; //PB10

B11
GPIO_InitStructure.GPIO_Mode =GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed =GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinRemapConfig(GPIO_FullRemap_TIM2, ENABLE);

  /* Enable the TIM3 global Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  TIM_TimeBaseStructure.TIM_Period = 0xFFFF;     //周期0～FFFF
      TIM_TimeBaseStructure.TIM_Prescaler = 35;       //时钟分频输入捕获周期时间大于外接周期
      TIM_TimeBaseStructure.TIM_ClockDivision = 0;   //时钟分割
      TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//模式
      TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);//基本初始化

TIM_ICInitStructure.TIM_Channel =TIM_Channel_2;
TIM_ICInitStructure.TIM_ICPolarity =TIM_ICPolarity_Rising;    //上升沿触发
TIM_ICInitStructure.TIM_ICSelection =TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler =TIM_ICPSC_DIV1;     //每检测到一个上升沿产生一次中断
TIM_ICInitStructure.TIM_ICFilter =0x0;
TIM_ICInit(TIM2, &TIM_ICInitStructure);

TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
TIM_ClearFlag(TIM2, TIM_FLAG_Update); //清除溢出中断标志
   TIM_Cmd(TIM2, ENABLE);
void TIM2_IRQHandler(void)
{

    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
   {

   /*必须清空标志位*/

if(CaptureNumber ==0)
{
ICReadValue1 = TIM_GetCapture2(TIM2);
        CaptureNumber = 1;
}
else  if(CaptureNumber ==1)
{
      ICReadValue2 = TIM_GetCapture2(TIM2);

      /* Capture computation */
      if (ICReadValue2 > ICReadValue1)
      {
        Capture = (ICReadValue2 - ICReadValue1);
      }
      else
      {
        Capture = ((0xFFFF - ICReadValue1) + ICReadValue2);
      }
      /* Frequency computation */
      TIM3Freq = (float)  (SystemCoreClock/ Capture/36); //输入信号的频率=TIM2的频率/两次捕获的时间
      CaptureNumber = 0;

}
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
   }

}