stm32f103 TIM1 输入捕获 测量频率 周期 占空比代码

下面是STM32F103 TIM1输入捕获测量频率，周期和占空比的代码示例：

1. 配置TIM1为输入捕获模式：

TIM_ICInitTypeDef TIM_ICInitStructure;
TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0x0;
TIM_ICInit(TIM1, &TIM_ICInitStructure);
TIM_Cmd(TIM1, ENABLE);

2. 定义变量存储捕获的值：

uint16_t IC1Value = 0;
uint16_t IC2Value = 0;

3. 在TIM1输入捕获中断处理函数中获取捕获的值：

void TIM1_CC_IRQHandler(void)
{
    if(TIM_GetITStatus(TIM1, TIM_IT_CC1) != RESET)
    {
        TIM_ClearITPendingBit(TIM1, TIM_IT_CC1);
        IC1Value = TIM_GetCapture1(TIM1);
    }
    else if(TIM_GetITStatus(TIM1, TIM_IT_CC2) != RESET)
    {
        TIM_ClearITPendingBit(TIM1, TIM_IT_CC2);
        IC2Value = TIM_GetCapture2(TIM1);
    }
}

4. 计算测量值：

uint32_t TIM1Freq = SystemCoreClock / (TIM_GetPrescaler(TIM1) + 1);
uint32_t TIM1Period = (IC2Value - IC1Value + 0xFFFF) % 0xFFFF;
float TIM1DutyCycle = 100.0 * (IC2Value - IC1Value) / TIM1Period;

其中，`SystemCoreClock`为系统时钟频率。

完整代码示例：

#include "stm32f10x.h"

uint16_t IC1Value = 0;
uint16_t IC2Value = 0;

int main(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

    TIM_ICInitTypeDef TIM_ICInitStructure;
    TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICFilter = 0x0;
    TIM_ICInit(TIM1, &TIM_ICInitStructure);

    TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;
    TIM_ICInit(TIM1, &TIM_ICInitStructure);

    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = TIM1_CC_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    TIM_ITConfig(TIM1, TIM_IT_CC1 | TIM_IT_CC2, ENABLE);
    TIM_Cmd(TIM1, ENABLE);

    while(1);
}

void TIM1_CC_IRQHandler(void)
{
    if(TIM_GetITStatus(TIM1, TIM_IT_CC1) != RESET)
    {
        TIM_ClearITPendingBit(TIM1, TIM_IT_CC1);
        IC1Value = TIM_GetCapture1(TIM1);
    }
    else if(TIM_GetITStatus(TIM1, TIM_IT_CC2) != RESET)
    {
        TIM_ClearITPendingBit(TIM1, TIM_IT_CC2);
        IC2Value = TIM_GetCapture2(TIM1);
    }

    uint32_t TIM1Freq = SystemCoreClock / (TIM_GetPrescaler(TIM1) + 1);
    uint32_t TIM1Period = (IC2Value - IC1Value + 0xFFFF) % 0xFFFF;
    float TIM1DutyCycle = 100.0 * (IC2Value - IC1Value) / TIM1Period;
}