stm32采用定时器中断捕获大于200k信号，误差超大，怎么改进

xiaolegeyong · 发表于 2020-3-13 22:26:43

//IO口配置
  gpio_initstruct.Pin = GPIO_PIN_2;
gpio_initstruct.Mode = GPIO_MODE_AF_PP;
gpio_initstruct.Pull = GPIO_NOPULL;
gpio_initstruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
gpio_initstruct.Alternate = GPIO_AF3_TIM9;
HAL_GPIO_Init(GPIOA, &gpio_initstruct);
//定时器配置
  htim9.Instance = TIM9;
  htim9.Init.Prescaler =0;//不分配
  htim9.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim9.Init.Period = 65535;    //0-65535
  htim9.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim9.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;

  if (HAL_TIM_IC_Init(&htim9) != HAL_OK)
  {
return 1;
  }
  sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
  sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
  sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;//
  sConfigIC.ICFilter = 0;//不滤波
  if (HAL_TIM_IC_ConfigChannel(&htim9, &sConfigIC, TIM_CHANNEL_1) != HAL_OK)
  {
return 1;
  }
如何改进呢，需要捕获的信号最大可达到1m？
测试过程捕获产生中断时HAL_TIM_ReadCapturedValue读捕获值，两次捕获高电平差用来计算频率，大于500k信号时误差太大