stm32f205 用定时器12，通道2做红外遥控，遥控的每个按键捕获脉冲宽度都一样，大神门，这是怎么回事啊

yang627468471 · 发表于 2014-9-17 10:40:46

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM12, ENABLE);
   GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_TIM12);
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
   GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
   GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
   GPIO_Init(GPIOB, &GPIO_InitStructure);

    TIM_TimeBaseStructure.TIM_Period = 65535;
   TIM_TimeBaseStructure.TIM_Prescaler =29;
   TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割
   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//TIM 向上计数模式
   TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
   TIM_TimeBaseInit(TIM12, &TIM_TimeBaseStructure);//根据指定的参数初始化 TIMx


   TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
   TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;//上升沿捕获
   TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//管脚与寄存器对应关系
   TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频
   TIM_ICInitStructure.TIM_ICFilter = 0x0;        //滤波设置，经历几个周期跳变认定波形稳定0x0～0xF
   TIM_ICInit(TIM12, &TIM_ICInitStructure);       //初始化定时器输入捕获通道
   TIM_Cmd(TIM12,ENABLE );    //使能定时器1
    TIM_ITConfig( TIM12,TIM_IT_CC2,ENABLE);

   NVIC_InitStructure.NVIC_IRQChannel = TIM8_BRK_TIM12_IRQn;
   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority =0; //先占优先级0级
   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //从优先级1级
   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
   NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器

void TIM8_BRK_TIM12_IRQHandler(void)
{
   static vu8 id = 0 ;
static vu16 cur_value = 0 ;
static vu16 last_value = 0 ;

u16 capture_value ;
//int capture_time;
u32 capture_time;
if(TIM_GetITStatus(TIM12,TIM_IT_CC2))
{
    TIM_ClearITPendingBit(TIM12, TIM_IT_CC2); //清中断标志
     cur_value =TIM_GetCapture2(TIM12) ; //获取捕获值
   if(cur_value >= last_value )
    {
      capture_value = cur_value - last_value ;
    }
    else
    {
      capture_value = 65536 - last_value + cur_value ;
    }
   last_value = cur_value ;
    //capture_time 为两次捕获的计数值的差，为了避免浮点数运算，此处，把浮点数放大十倍，转换成整数计算。
    capture_time = capture_value *10 / (2400) ;
   printf("capture_time=%x\r\n",capture_time);
    // 引导码+单击码，9+4.5=13.5ms
    if( (capture_time > 130) && (capture_time <140) )
    {
      id = 0 ;
      //Addr_Comd_pBuffer = 0;
      IR_STATUS_RSE(Clr_IR_STATUS);
      IR_STATUS_SET(IRDaRec_START);
    }
    //连续码：9+2.5=11.5ms 周期108ms
    else if( (capture_time > 110 ) && (capture_time <120 ))
    {
       id=0;
       RepCode_CNT_INC();//按键次数加1
       IR_STATUS_SET(IRDaRec_OK);
    }
    // 1.125ms
    else if( (capture_time > 9 ) && (capture_time <13 )&&IS_STATUS_IR(IRDaRec_START))
    {
      Addr_Comd_pBuffer<<=1;
      Addr_Comd_pBuffer+=0;
      id++;
    }
    // 2.245ms
    else if( (capture_time > 20 ) && (capture_time <24 )&&IS_STATUS_IR(IRDaRec_START))
    {
      Addr_Comd_pBuffer<<=1;
      Addr_Comd_pBuffer+=1;
      id++;
    }
    if(id>=59)
   {
      id = 0;
   }
    if((id >=32)&&IS_STATUS_IR(IRDaRec_START))
    {
      /*UART1_SendByte(Addr_Comd_pBuffer);
      UART1_SendByte(Addr_Comd_pBuffer>>8);
      UART1_SendByte(Addr_Comd_pBuffer>>16);
      UART1_SendByte(Addr_Comd_pBuffer>>24);*/
      id = 0;
      IR_STATUS_SET(IRDaRec_OK);
      IR_STATUS_RSE(IRDaRec_START);
      //test_ir();
    }
   tsk_IR();
}

}
以下是捕获脉冲结果，每个红外按键都一样