F407 定时器3 PWM输入测量频率和占空比，低于1289Hz时定时器会溢出，如何使用更新中断计算溢出次数，达到测量1Hz的效果？

郭瑞晨

void TIM3_CH1_PWMIN_Init(u16 arr,u16 psc)
{
        TIM_ICInitTypeDef  TIM3_ICInitStructure;
        GPIO_InitTypeDef GPIO_InitStructure;
        TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
        NVIC_InitTypeDef NVIC_InitStructure;

        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);          //TIM3时钟使能   
        RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);         //使能PORTA时钟       
       
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; //PA6
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;        //速度100MHz
        GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
        GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; //下拉
        GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA6

        GPIO_PinAFConfig(GPIOA,GPIO_PinSource6,GPIO_AF_TIM3); //PB6复用位定时器3

        TIM_TimeBaseStructure.TIM_Prescaler=psc;  //定时器分频
        TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
        TIM_TimeBaseStructure.TIM_Period=arr;   //自动重装载值
        TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
       
        TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);
       
        //初始化TIM4输入捕获参数
        TIM3_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01         选择输入端 IC1映射到TI1上
  TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;        //上升沿捕获
  TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上
  TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;         //配置输入分频,不分频
  TIM3_ICInitStructure.TIM_ICFilter = 0x0;//IC1F=0000 配置输入滤波器 不滤波

        TIM_PWMIConfig(TIM3, &TIM3_ICInitStructure);
/* Select the TIM3 Input Trigger*/
  TIM_SelectInputTrigger(TIM3, TIM_TS_TI1FP1);
/* Select the slave Mode: Reset Mode */
  TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);
/* Enable the Master/Slave Mode */
  TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable);
/* Enable the CC1,2 Interrupt Request */
  TIM_ITConfig(TIM3, TIM_IT_CC2|TIM_IT_CC1|TIM_IT_Update, ENABLE);

  TIM_Cmd(TIM3,ENABLE );         //使能定时器3

  NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;//抢占优先级2
        NVIC_InitStructure.NVIC_IRQChannelSubPriority =0;                //子优先级0
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                        //IRQ通道使能
        NVIC_Init(&NVIC_InitStructure);        //根据指定的参数初始化VIC寄存器、
}

float Period,Freq,T,IC2Value,Q;
u16        TIM5CH1_CAPTURE_VAL=0;        //输入捕获值
//定时器3中断服务程序
void TIM3_IRQHandler(void)
{
        if(TIM_GetITStatus(TIM3,TIM_IT_Update) == SET)
  {
                TIM_ClearITPendingBit(TIM3,TIM_IT_Update);
                TIM5CH1_CAPTURE_VAL++;
                printf("TIM5CH1_CAPTURE_VAL=%d\r\n",TIM5CH1_CAPTURE_VAL);//一直是1
        }
        POINT_COLOR=RED;
  if(TIM_GetITStatus(TIM3,TIM_IT_CC1) == SET)
  {
                TIM_ClearITPendingBit(TIM3,TIM_IT_CC1);
    Period = TIM_GetCapture1(TIM3)+1+65536*(TIM5CH1_CAPTURE_VAL); //计算错误
                TIM5CH1_CAPTURE_VAL=0;
                printf("Period=%.2f\r\n",Period);
                T=(Period)/(84/(TIM_GetPrescaler(TIM3)+1));
    Freq = 1000000/T;
                printf("Freq=%.2f\r\n",Freq);
  }
  if(TIM_GetITStatus(TIM3,TIM_IT_CC2) == SET)
  {
                TIM_ClearITPendingBit(TIM3,TIM_IT_CC2);
    IC2Value = TIM_GetCapture2(TIM3)+1;
          printf("IC2Value=%.2f\r\n",IC2Value);
                Q=(100*IC2Value)/Period;
                printf("Q=%.0f\r\n",Q);
  }
        delay_ms(490);       
}

正点原子

参考我们红外遥控的处理方式

Electronic

F4有32位的定时器啊，用32位的定时器岂不是更加简单