输入信号捕获，求教原子及各位大侠

dtm

TIM4_CH1和TIM4_CH2(PB6、PB7)两个引脚输入方波信息，采集方波个数及频率。
定时器4为采集通道，定时器3为定时器为100ms中断，存历史数据到TIM4CH1_SAVE_VAL和TIM4CH2_SAVE_VAL 数组（长度为10），TIM4CH1_FREQ_VAL为1s内方波个数
定时器3的100ms中断没有问题，用示波器测试了的。

问题1：输入1KHz方波，CH1采集获得频率为90，CH2通道获得频率为180！
问题2：输入为10hz以下时，输出数据为几十，数据不定，如1hz输出60左右，2hz输出80左右。

代码奉上：
定时器4初始化
//定时器4通道1,2输入捕获设置
void TIM4_Cap_Init(u16 arr,u16 psc)
{ 
 TIM_ICInitTypeDef  TIM4_ICInitStructure;
 GPIO_InitTypeDef GPIO_InitStructure;
 TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  NVIC_InitTypeDef NVIC_InitStructure;

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); 
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);  
 
 GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_6 | GPIO_Pin_7 ;  //PB6,7 
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PB6,7 
 GPIO_Init(GPIOB, &GPIO_InitStructure);
 GPIO_ResetBits(GPIOB,GPIO_Pin_6);       //PB6,7
 GPIO_ResetBits(GPIOB,GPIO_Pin_7);
  
 TIM_TimeBaseStructure.TIM_Period = arr;    
 TIM_TimeBaseStructure.TIM_Prescaler =psc;  
 TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 
 TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); 
  
  TIM4_ICInitStructure.TIM_Channel = TIM_Channel_1  ; //CC1S=01 
   TIM4_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //
   TIM4_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //
   TIM4_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;  //
   TIM4_ICInitStructure.TIM_ICFilter = 0x00;//
   TIM_ICInit(TIM4, &TIM4_ICInitStructure);
  
   TIM4_ICInitStructure.TIM_Channel = TIM_Channel_2  ;
   TIM4_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; 
   TIM4_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
   TIM4_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
   TIM4_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000
   TIM_ICInit(TIM4, &TIM4_ICInitStructure);
  
  NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;  //
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;  //
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;  //
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //
  NVIC_Init(&NVIC_InitStructure);  //
 
  TIM_ITConfig(TIM4,TIM_IT_CC1,ENABLE);//
  TIM_ITConfig(TIM4,TIM_IT_CC2,ENABLE);//
  
  TIM_Cmd(TIM4,ENABLE );  
}

//定时器4中断
void TIM4_IRQHandler(void)
{
  //TIM4_CH1
  if (TIM_GetITStatus(TIM4, TIM_IT_CC1) == SET )//
  {
   TIM4CH1_CAPTURE_VAL++;
   TIM_ClearITPendingBit(TIM4, TIM_IT_CC1);
  }
  //TIM4_CH2
  else if (TIM_GetITStatus(TIM4, TIM_IT_CC2) == SET )//
  {
   TIM4CH2_CAPTURE_VAL++;
   TIM_ClearITPendingBit(TIM4, TIM_IT_CC2);
  } 
  
//   TIM_ClearITPendingBit(TIM4, TIM_IT_CC2|TIM_IT_CC3|TIM_IT_Update);
}
//定时器3初始化
void TIM3_Int_Init(u16 arr,u16 psc)
{
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 NVIC_InitTypeDef NVIC_InitStructure;

 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

 TIM_TimeBaseStructure.TIM_Period = arr; 
 TIM_TimeBaseStructure.TIM_Prescaler =psc;
 TIM_TimeBaseStructure.TIM_ClockDivision = 0; 
 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; 
 TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); 
 
 TIM_ITConfig( TIM3, TIM_IT_Update , ENABLE );
 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  
 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; 
 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  
 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 
 NVIC_Init(&NVIC_InitStructure); 

 TIM_Cmd(TIM3, ENABLE); 
}

//定时器3中断
void TIM3_IRQHandler(void)  
{
 u16 i = 0;
 u32 TIM4CH1_VAL = 0;
 u32 TIM4CH2_VAL = 0;

 if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) 
 {
  TIM_ClearITPendingBit( TIM3, TIM_IT_Update );   
  
  TIM4CH1_VAL = TIM4CH1_CAPTURE_VAL;
  TIM4CH2_VAL = TIM4CH2_CAPTURE_VAL;
  TIM3_SYSTICKS++;
  LEDOUT = ((LEDIN + 1)&0x01);

  for( i=0;i<LEN_PWM_COUNT-1;i++ )
  {
    TIM4CH1_SAVE_VAL = TIM4CH1_SAVE_VAL[i+1];
    TIM4CH2_SAVE_VAL = TIM4CH2_SAVE_VAL[i+1];
  }
  TIM4CH1_SAVE_VAL[LEN_PWM_COUNT-1] = TIM4CH1_VAL;
  TIM4CH2_SAVE_VAL[LEN_PWM_COUNT-1] = TIM4CH2_VAL;
  
  TIM4CH1_FREQ_VAL = TIM4CH1_VAL - TIM4CH1_SAVE_VAL[0];
  TIM4CH2_FREQ_VAL = TIM4CH2_VAL - TIM4CH2_SAVE_VAL[0];
 }
}

//main函数
TIM4_Cap_Init(0XFFFF,72-1);    //
TIM3_Int_Init(999,7199);        //
while(1)
{
   memset(temp,0,64);
   sprintf(temp, "%d,[%d,%d] [%d,%d]", TIM3_SYSTICKS,TIM4CH1_FREQ_VAL,TIM4CH2_FREQ_VAL,TIM4CH1_CAPTURE_VAL,TIM4CH2_CAPTURE_VAL);//temp1[8] = '\0';
   uart_send( USART1,(u8*)temp,strlen( temp ) );
}

正点原子

楼主先搞定一个通道再说。
这个论坛也有大把参考，可以多看看别人的代码。