STM32输入捕获控制测量频率方法程序

void  TIM3_Confguration()

{  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

  TIM_ICInitTypeDef  TIM_ICInitStructure;

  /* Time base configuration */

  TIM_TimeBaseStructure.TIM_Period = 1000;  // 这两句for 1ms，stm32 有72Mhz，先72分频，再计数到1000=1ms

  TIM_TimeBaseStructure.TIM_Prescaler = 72;

  TIM_TimeBaseStructure.TIM_ClockDivision = 0;    

  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //上升沿计数

  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

   /* Clear TIM2 update pending flag[清除TIM2溢出中断标志] */

   TIM_ClearFlag(TIM3, TIM_FLAG_Update);

    /* Enable TIM3 Update interrupt [TIM3溢出中断允许]*/

  TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);  //以上配置的意思是1ms产生一个中断

  TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;       // Channel_1

  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;    //choose rising edge选择上升沿

  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;  //Direct connecte直接连接

  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;    //预分频器register every rising edages

  TIM_ICInitStructure.TIM_ICFilter = 0x03;    //used 3 period to wait for 系统信号接收正常

  TIM_ICInit(TIM3, &TIM_ICInitStructure);

  TIM_SelectInputTrigger(TIM3, TIM_TS_TI1FP1 );   //选择时钟触发源，这里只能用1或2，意味着通道34不能用输入触发（Trigger）

  TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);//触发方式

  TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable); //启动定时器的被动触发

 TIM_SetCompare1(TIM3, 0); //设置捕获计数器初值

 /* TIM3 enable counter */

 TIM_ClearITPendingBit(TIM3, TIM_IT_Update );

  TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);

  TIM_Cmd(TIM3, ENABLE);

}

   /* Enable the TIM3 gloabal Interrupt [允许TIM3全局中断]*/

  NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQChannel;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 4;  

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

  NVIC_Init(&NVIC_InitStructure);

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3 ，ENABLE）；

 //PA6 for TIM3 channel 1

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;

 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

    GPIO_Init(GPIOA, &GPIO_InitStructure);