stm32f103c8t6pwm输入捕获中断测上升沿时间

以下是使用STM32F103C8T6的输入捕获中断测量上升沿时间的步骤：

1. 使能定时器和GPIO对应的时钟，例如要使用TIM2通道2和PA1引脚，需要使能GPIOA和TIM2的时钟：

   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

2. 配置PA1引脚为输入模式：

   GPIO_InitTypeDef GPIO_InitStructure;
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
   GPIO_Init(GPIOA, &GPIO_InitStructure);

3. 初始化TIM2的基本定时器：

   TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
   TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
   TIM_TimeBaseStructure.TIM_Prescaler = 71;
   TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
   TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

4. 配置TIM2的通道2为输入捕获模式，并使能上升沿捕获：

   TIM_ICInitTypeDef TIM_ICInitStructure;
   TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
   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(TIM2, &TIM_ICInitStructure);

5. 开启TIM2的更新中断：

   TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

6. 使能TIM2：

   TIM_Cmd(TIM2, ENABLE);

7. 在TIM2的更新中断服务函数中读取捕获寄存器的值，即可得到上升沿时间：

   void TIM2_IRQHandler(void)
   {
       if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
       {
           TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
       }
       if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)
       {
           uint16_t capture = TIM_GetCapture2(TIM2);
           TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);
           // 处理上升沿时间
       }
   }