我在楼主的基础上 想再添加一些代码用TIM2的CH1来捕获TIM3的CH1，代码如下：
void TIM2_PWMINPUT_INIT(u16 arr,u16 psc) { TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure; NVIC_InitTypeDef NVIC_InitStructure; TIM_ICInitTypeDef  TIM2_ICInitStructure; GPIO_InitTypeDef GPIO_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);     //Open TIM4 clock         RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
                                       GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;                               //GPIO??         GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;         GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;         GPIO_Init(GPIOA, &GPIO_InitStructure); TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存   TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值   TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式 TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参         NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;                              NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;         NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;         NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;         NVIC_Init(&NVIC_InitStructure);              TIM2_ICInitStructure.TIM_Channel = TIM_Channel_1;                            TIM2_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;                TIM2_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;            TIM2_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;  TIM2_ICInitStructure.TIM_ICFilter = 0x0;            TIM_PWMIConfig(TIM2, &TIM2_ICInitStructure);     //PWM输入配置                    TIM_SelectInputTrigger(TIM2, TIM_TS_TI1FP1);     //选择有效输入端                 TIM_SelectSlaveMode(TIM2, TIM_SlaveMode_Reset);  //配置为主从复位模式         TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);                                                TIM_ITConfig(TIM2, TIM_IT_CC1|TIM_IT_Update, ENABLE);          //中断配置 TIM_ClearITPendingBit(TIM2, TIM_IT_CC1|TIM_IT_Update); //清除中断标志位 TIM_Cmd(TIM2, ENABLE);     } void TIM2_IRQHandler(void) {
if(CollectFlag1) { if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)//捕获1发生捕获事件 { duty1 = TIM_GetCapture1(TIM2); //采集占空比  period1 = TIM_GetCapture2(TIM2);     //采集周期 } CollectFlag1 = 0; } TIM_ClearITPendingBit(TIM2, TIM_IT_CC1|TIM_IT_Update); //清除中断标志位 }




主函数：
extern void TIM3_PWM_Init(u16 arr,u16 psc); extern void TIM4_PWMINPUT_INIT(u16 arr,u16 psc); extern void TIM2_PWMINPUT_INIT(u16 arr,u16 psc);
extern u16 period; extern u16 duty ; extern u8 CollectFlag ; extern u16 period1; extern u16 duty1 ; extern u8 CollectFlag1 ; //Mini STM32开发板范例代码8
//技术论坛:www.openedv.com    int main(void)  { SystemInit(); delay_init(72);     //延时初始化 NVIC_Configuration();   //中断配置 uart_init(9600); //串口初始化 TIM3_PWM_Init(1000,7200-1);   //1KHZ周期 TIM_SetCompare1(TIM3,200); //设置占空比 TIM_SetCompare2(TIM3,401); //设置占空比 TIM_SetCompare3(TIM3,600); //设置占空比 TIM_SetCompare4(TIM3,800); //设置占空比 TIM4_PWMINPUT_INIT(0xffff,7200-1);   //pwm输入初始化以1M的频率捕捉 TIM2_PWMINPUT_INIT(0xffff,7200-1);
// PWM_Init(900,0); //不分频。PWM频率=72000/900=8Khz while(1) { delay_ms(100);    if(!CollectFlag) { printf("duty   = %d%% ",duty*100/period); //打印占空比 printf("cycle = %dKHz ",1000/period);//打印周期另一种叫法 printf("period  = %dus ",period);    //打印周期 CollectFlag = 1; } delay_ms(10); if(!CollectFlag1) { printf("duty1   = %d%% ",duty1*100/period1); //打印占空比 printf("cycle1 = %dKHz ",1000/period1);//打印周期另一种叫法 printf("period1  = %dus ",period1);    //打印周期 CollectFlag1 = 1; } }  
 }
得出下面的结果：

只有原先楼主的那个测量是准确的 ，能问一下哪错了吗？

很好 学习了

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回复【47楼】xianyangrui:
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好东西，赞一个。谢谢分享