STM32编码器捕捉频率并同步到步进电机问题请教

//输入捕获

static void TIM2_Mode_Config(void)

{

    TIM_TimeBaseInitTypeDef   TIM_TimeBaseStructure;

    TIM_ICInitTypeDef  TIM_ICInitStructure;

    TIM_DeInit(TIM2);

    

    /* Time base configuration */

    

    TIM_TimeBaseStructure.TIM_Period = 0xffff;          

    //TIM_TimeBaseStructure.TIM_Prescaler = 719;

    TIM_TimeBaseStructure.TIM_Prescaler = 71;

    TIM_TimeBaseStructure.TIM_ClockDivision = 0;    

    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 

    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    

    TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;

    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;

    //TIM输入2，3或4选择对应地与IC1或IC2或IC3或IC4相连

    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;

    //TIM捕获在捕获输入上每探测到一个边沿执行一次 TIM_ICPSC_DIV2\TIM_ICPSC_DIV4\TIM_ICPSC_DIV8

    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;

    //选择输入比较滤波器 0x0 - 0xF

    TIM_ICInitStructure.TIM_ICFilter = 0x0;  //

    

    TIM_PWMIConfig(TIM2, &TIM_ICInitStructure);

    

    /* Select the TIM3 Input Trigger: TI2FP2 */

    TIM_SelectInputTrigger(TIM2, TIM_TS_TI2FP2);

    

    /* Select the slave Mode: Reset Mode */

    TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset);

    

    /* Enable the Master/Slave Mode */

    TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);    

    

    /* Enable the CC2 Interrupt Request */

    TIM_ITConfig(TIM2, TIM_IT_CC2, ENABLE);

    

    /* TIM enable counter */

    TIM_Cmd(TIM2, ENABLE);    

}

void TIM2_ISR(void)

{



    Uint16 TIM3_Period; //ARR

    Uint16 TIM3_CCR3_Val; //CCR3

    Uint16 IC2Value;



    TIM_ClearITPendingBit(TIM2, TIM_IT_CC2); //清除中断标志位

    IC2Value = TIM_GetCapture2(TIM2);

    if(IC2Value != 0) 

    { 

        //DutyCyle = (TIM_GetCapture1(TIM3) * 100) / IC2Value; //占空比计算

        //TIM3_Period = 72000000 / IC2Value; //0 -72M

        //TIM3_Period = 1000000 / IC2Value; //71 -1M

        //TIM3_Period = 100000 / IC2Value; //719 -100K

        

        /*

            同频捕获同频率输出

            TIM_Prescaler = 71, 即(71+1)=72分频，时钟频率降为1M

            TIM2和TIM3同频率，TIM2每个时钟周期捕获到的脉冲不用计算，可以直接输出给TIM3

        */

        

        TIM3_Period = IC2Value; 

        TIM3_CCR3_Val = ((TIM3_Period + 1)/2);

    } 

    else 

    { 

        TIM3_Period = 0; 

        TIM3_CCR3_Val = 0; 

    }

    

    /* 同步改变TIM3步进脉冲 */

    

    TIM3->ARR=TIM3_Period;//设定计数器自动重装值

    TIM3->CCR3=TIM3_CCR3_Val;

}