STM32定时器做外部脉冲信号计数器用

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STM32定时器做外部脉冲信号计数器用 [复制链接]

今天，尝试使用STM32的计数器的外部时钟功能，来对外部脉冲信号进行计数。效果还不错。具体设置如下：

/*       TIM3_CH2 为脉冲输入口
1.  配置GPIO_GPIOA_PIN7 输入
2.  配置TIM3 计数器在TI2 端的上升沿计数:
    1). TIMx_CCMR1: CC2S =01;      配置通道2检测TI2输入的上升沿
    2). TIMx_CCMR1:IC2F  =000;     选择输入滤波器带宽
    3). TIMx_CCER:  CC2P =0;         配置上升沿极性                                 √
    4). TIMx_SMCR:  SMS  =111;     选择定时器外部时钟模式1
    5). TIMx_SMCR:  TS    =110;     选择TI2作为触发输入源                   √
    6). TIMx_CR1:    CEN  =1;        启动计数器
*/

void TIM3_External_Clock_CountingMode(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
 //   TIM_ICInitTypeDef  TIM_ICInitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
   
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_Init(GPIOA, &GPIO_InitStructure);

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    TIM_DeInit(TIM3);
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    TIM_TimeBaseStructure.TIM_Prescaler = 0x00;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; /*定时器时钟(CK_INT)频率与数字滤波器(ETR,TIx)
                                                                            使用的采样频率之间的分频比为1*/
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit( TIM3, &TIM_TimeBaseStructure); // Time base configuration 
   
/*
    tmpccmr1 |= (uint16_t)(TIM_ICFilter << 12);       // CCMR1_IC2F
    tmpccmr1 |= (uint16_t)(TIM_ICSelection << 8);   // CCMR1_CC2S

    由TIM_TIxExternalCLK1Source_TI2决定了
    TIM_ICSelection=TIM_ICSelection_DirectTI:     CCMR1_CC2S = 01;

    TIM_ICPolarity_Rising               = CCER_CC2P
    TIM_TIxExternalCLK1Source_TI2 = TIM_SMCR_TS

    该函数定义了TIM_SlaveMode_External1;外部时钟模式1
*/
                            
TIM_TIxExternalClockConfig(TIM3,TIM_TIxExternalCLK1Source_TI2,TIM_ICPolarity_Rising,0);
//  TIM_SetCounter(TIM3, 0);   // 清零计数器CNT
//  TIM_Cmd(TIM3,ENABLE); 

}

 

// 下面是使用方法：

    TIM3_External_Clock_CountingMode();
    TIM_SetCounter(TIM3, 0);   // 清零计数器CNT
    TIM_Cmd(TIM3,ENABLE); 
    SecCnt = 0;
    TFgs.Secok = 0;
    i=0;
    while(1)
    {
        Delay_Nms(1000);
            CountPulse = TIM_GetCounter(TIM3);       
            DisplayDat(10,10+24*i,CountPulse,5);

            TFgs.Secok = 0;
            if(++CountTims>=120)
            {
                    TIM_Cmd(TIM3,DISABLE); 
                    CountPulse = TIM_GetCounter(TIM3);       
                    DisplayDat(10,10+24*i,CountPulse,5);
                    if(++i>11)i=0;
                    TIM_SetCounter(TIM3, 0);   // 清零计数器CNT
    TIM_Cmd(TIM3,ENABLE); 
    SecCnt = 0;
    TFgs.Secok = 0;
                    CountTims =0;
            }
    };