問題：使用定時(shí)器1的通道3（管腳PC3）不能收到捕獲值，但使用定時(shí)器1的通道1（管腳PD2）可以收到并打印捕獲值。

輸入脈沖波形：

例程使用定時(shí)器1的通道1，PD2輸入捕獲，可以收到捕獲值，打印日志：

使用定時(shí)器1的通道3，PC3輸入捕獲，不能收到捕獲值，間歇有打?。?/p>

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一些代碼說明

例程定時(shí)器1通道1，PD2初始化函數(shù)：

void?Input_Capture_Init(u16?arr,?u16?psc)
{
????GPIO_InitTypeDef????????GPIO_InitStructure?=?{0};
????TIM_ICInitTypeDef???????TIM_ICInitStructure?=?{0};
????TIM_TimeBaseInitTypeDef?TIM_TimeBaseInitStructure?=?{0};
????NVIC_InitTypeDef????????NVIC_InitStructure?=?{0};

????RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD?|?RCC_APB2Periph_TIM1,?ENABLE);

????GPIO_InitStructure.GPIO_Pin?=?GPIO_Pin_2;
????GPIO_InitStructure.GPIO_Mode?=?GPIO_Mode_IN_FLOATING;
????GPIO_Init(GPIOD,?&GPIO_InitStructure);
????GPIO_ResetBits(GPIOD,?GPIO_Pin_2);

????TIM_TimeBaseInitStructure.TIM_Period?=?arr;
????TIM_TimeBaseInitStructure.TIM_Prescaler?=?psc;
????TIM_TimeBaseInitStructure.TIM_ClockDivision?=?TIM_CKD_DIV1;
????TIM_TimeBaseInitStructure.TIM_CounterMode?=?TIM_CounterMode_Up;
????TIM_TimeBaseInitStructure.TIM_RepetitionCounter?=?0x00;
????TIM_TimeBaseInit(TIM1,?&TIM_TimeBaseInitStructure);

????TIM_ICInitStructure.TIM_Channel?=?TIM_Channel_1;
????TIM_ICInitStructure.TIM_ICPrescaler?=?TIM_ICPSC_DIV1;
????TIM_ICInitStructure.TIM_ICFilter?=?0x00;
????TIM_ICInitStructure.TIM_ICPolarity?=?TIM_ICPolarity_Falling;
????TIM_ICInitStructure.TIM_ICSelection?=?TIM_ICSelection_DirectTI;

????TIM_PWMIConfig(TIM1,?&TIM_ICInitStructure);

????NVIC_InitStructure.NVIC_IRQChannel?=?TIM1_CC_IRQn;
????NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority?=?2;
????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_SelectInputTrigger(TIM1,?TIM_TS_TI1FP1);
????TIM_SelectSlaveMode(TIM1,?TIM_SlaveMode_Reset);
????TIM_SelectMasterSlaveMode(TIM1,?TIM_MasterSlaveMode_Enable);
????TIM_Cmd(TIM1,?ENABLE);
}

調(diào)用為：

Input_Capture_Init(0xFFFF,?48000?-?1);

定時(shí)1通道3，PC3的初始化代碼：

void?Input_Capture_Init_PC3(u16?arr,?u16?psc)
{
????GPIO_InitTypeDef????????GPIO_InitStructure?=?{0};
????TIM_ICInitTypeDef???????TIM_ICInitStructure?=?{0};
????TIM_TimeBaseInitTypeDef?TIM_TimeBaseInitStructure?=?{0};
????NVIC_InitTypeDef????????NVIC_InitStructure?=?{0};

????RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC?|?RCC_APB2Periph_TIM1,?ENABLE);

????GPIO_InitStructure.GPIO_Pin?=?GPIO_Pin_3?;
????GPIO_InitStructure.GPIO_Mode?=?GPIO_Mode_IN_FLOATING;
????GPIO_Init(GPIOC,?&GPIO_InitStructure);
????GPIO_ResetBits(GPIOC,??GPIO_Pin_3);

????TIM_TimeBaseInitStructure.TIM_Period?=?arr;
????TIM_TimeBaseInitStructure.TIM_Prescaler?=?psc;
????TIM_TimeBaseInitStructure.TIM_ClockDivision?=?TIM_CKD_DIV1;
????TIM_TimeBaseInitStructure.TIM_CounterMode?=?TIM_CounterMode_Up;
????TIM_TimeBaseInitStructure.TIM_RepetitionCounter?=?0x00;
????TIM_TimeBaseInit(TIM1,?&TIM_TimeBaseInitStructure);

????TIM_ICInitStructure.TIM_Channel?=??TIM_Channel_3;
????TIM_ICInitStructure.TIM_ICPrescaler?=?TIM_ICPSC_DIV1;
????TIM_ICInitStructure.TIM_ICFilter?=?0x00;
????TIM_ICInitStructure.TIM_ICPolarity?=?TIM_ICPolarity_Rising;
????TIM_ICInitStructure.TIM_ICSelection?=?TIM_ICSelection_DirectTI;

????TIM_PWMIConfig(TIM1,?&TIM_ICInitStructure);

????NVIC_InitStructure.NVIC_IRQChannel?=?TIM1_CC_IRQn;
????NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority?=?2;
????NVIC_InitStructure.NVIC_IRQChannelSubPriority?=?0;
????NVIC_InitStructure.NVIC_IRQChannelCmd?=?ENABLE;
????NVIC_Init(&NVIC_InitStructure);

????TIM_ITConfig(TIM1,?TIM_IT_CC3?,?ENABLE);

????TIM_SelectInputTrigger(TIM1,?TIM_TS_TI1FP1);
????TIM_SelectSlaveMode(TIM1,?TIM_SlaveMode_Reset);
????TIM_SelectMasterSlaveMode(TIM1,?TIM_MasterSlaveMode_Enable);
????TIM_Cmd(TIM1,?ENABLE);
}

調(diào)用為：

Input_Capture_Init_PC3(0xFFFF,?48000?-?1);

定時(shí)器通道中斷處理函數(shù)：

void?TIM1_CC_IRQHandler(void)
{
????if(?TIM_GetITStatus(?TIM1,?TIM_IT_CC1?)?!=?RESET?)
????{
????????uint16_t?_tmp?=?TIM_GetCapture1(?TIM1?);
????????if(!g_flag_counter)
????????{
????????????g_counter++;
????????????g_input_value?+=?_tmp;
????????????if(g_counter?>=?MAX_COUNTER)
????????????{
????????????????g_flag_counter?=?1;
????????????}
????????}
????????printf(?"CH1_Val:%d,?counter:%d,?flag:%d\r\n",?_tmp,?g_counter,?g_flag_counter);
????????//printf(?"CH1_Val:%d\r\n",?TIM_GetCapture1(?TIM1?));
????????TIM_SetCounter(?TIM1,?0?);
????}

????if(?TIM_GetITStatus(?TIM1,?TIM_IT_CC2?)?!=?RESET?)
????{
????????printf(?"CH2_Val:%d\r\n",?TIM_GetCapture2(?TIM1?)?);
????}

????if(?TIM_GetITStatus(?TIM1,?TIM_IT_CC3?)?!=?RESET?)
????{
????????uint16_t?_tmp?=?TIM_GetCapture3(?TIM1?);
????????if(!g_flag_counter)
????????{
????????????g_counter++;
????????????g_input_value?+=?_tmp;
????????????if(g_counter?>=?MAX_COUNTER)
????????????{
????????????????g_flag_counter?=?1;
????????????}
????????}

????????printf(?"CH3_Val:%d\r\n",?TIM_GetCapture3(?TIM1?)?);
????}

????TIM_ClearITPendingBit(?TIM1,?TIM_IT_CC1?|?TIM_IT_CC2?|?TIM_IT_CC3);
}

主函數(shù)調(diào)用：

int?main(void)
{
????USART_Printf_Init(115200);
????printf("Input_Capture_SystemClk2:%d\r\n",?SystemCoreClock);

????TIM2_PWMOut_Init(100,?48000?-?1,?pbuf[0]);
????TIMx_DMA_Init(DMA1_Channel2,?(u32)TIM2_CH1CVR_ADDRESS,?(u32)pbuf,?3);

????TIM_DMACmd(TIM2,?TIM_DMA_Update,?ENABLE);
????TIM_Cmd(TIM2,?ENABLE);
????TIM_CtrlPWMOutputs(TIM2,?ENABLE);

//????Input_Capture_Init(0xFFFF,?48000?-?1);
????Input_Capture_Init_PC3(0xFFFF,?48000?-?1);

????while(1)
????{
????????if(g_flag_init?==?0)
????????{
????????????printf("prj_init_ok\n");
????????????g_flag_init?=?1;
????????}
????????if(g_flag_counter)
????????{
????????????printf("Average:?%d/%d=%d\n",?g_input_value,g_counter,?g_input_value/g_counter);
????????????g_input_value?=?0;
????????????g_counter?=?0;
????????????g_flag_counter?=?0;
????????}
????}
}

您好，PWM輸入模式只能使用TIMx_CH1 /TIMx_CH2信號(hào)，需要將這行代碼TIM_PWMIConfig(TIM1, &TIM_ICInitStructure);

改成TIM_ICInit(TIM1, &TIM_ICInitStructure); 輸入捕獲模式