STM32输入捕捉问题，麻烦看一下，谢谢！

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输入捕捉高电平的时间，用定时器TIM3，通道3、通道4.但是捕捉通过串口输出RC_CH[4]、RC_CH[5]数组值为0，不知道什么原因，是不是定时器没有配置好，代码如下：

[mw_shl_code=c,true]u8 TIM3CH3_CAPTURE_STA=0; //通道3输入捕获状态 u16 TIM3CH3_CAPTURE_UPVAL; //通道3输入捕获值 u16 TIM3CH3_CAPTURE_DOWNVAL;//通道3输入捕获值 u8 TIM3CH4_CAPTURE_STA=0; //通道4输入捕获状态 u16 TIM3CH4_CAPTURE_UPVAL; //通道4输入捕获值 u16 TIM3CH4_CAPTURE_DOWNVAL;//通道4输入捕获值 u16 RC_CH[8]; void TIM3_Init(void) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; TIM_ICInitTypeDef TIM3_ICInitStructure; NVIC_InitTypeDef NVIC_InitStructure; //设置NVIC中TIM3中断 NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;//通道设置为TIM3 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;//抢占0 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;//响应3 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//打开中断通道 NVIC_Init(&NVIC_InitStructure);//写入配置 RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);//使能TIM3时钟 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);//GPIOB 时钟开启 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1; //GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉输入 GPIO_Init(GPIOB, &GPIO_InitStructure);//GPIOB 0 1口配置 GPIO_ResetBits(GPIOB,GPIO_Pin_0|GPIO_Pin_1); TIM_TimeBaseStructure.TIM_Period = 20000-1; TIM_TimeBaseStructure.TIM_Prescaler = (72 - 1);//时钟预分频数 72M/72(1M/20000) = 50HZ TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;//设置时钟分频系数：不分频 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;//向上计数模式(0->?) TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);//配置TIM2 //初始化TIM3输入捕获参数 TIM3_ICInitStructure.TIM_Channel = TIM_Channel_3; //CC1S=01 选择输入端 IC1映射到TI1上 TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获 TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上 TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频 TIM3_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器 不滤波 TIM_ICInit(TIM3, &TIM3_ICInitStructure); TIM3_ICInitStructure.TIM_Channel = TIM_Channel_4; //CC1S=01 选择输入端 IC1映射到TI1上 TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获 TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上 TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频 TIM3_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置输入滤波器 不滤波 TIM_ICInit(TIM3, &TIM3_ICInitStructure); TIM_ITConfig(TIM3,TIM_IT_CC3,ENABLE);//允许CC3IE捕获中断 TIM_ITConfig(TIM3,TIM_IT_CC4,ENABLE);//允许CC4IE捕获中断 TIM_Cmd(TIM3,ENABLE);//使能定时器2 } //定时器3中断服务程序 void TIM3_IRQHandler(void) { if(TIM_GetITStatus(TIM3, TIM_IT_CC3) == SET)//捕获1发生捕获事件 { TIM_ClearITPendingBit(TIM3, TIM_IT_CC3);//清除捕获1标志位 if(TIM3CH3_CAPTURE_STA == 0)//捕获到上升沿 { TIM3CH3_CAPTURE_UPVAL = TIM_GetCapture1(TIM3);//获取上升沿的数据 TIM3CH3_CAPTURE_STA = 1; //标记以捕获到了上升沿 TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Falling);//设置为下降沿捕获 } else //捕获到下降沿 (已经捕获到一个完整的高电平脉冲！) { TIM3CH3_CAPTURE_DOWNVAL = TIM_GetCapture1(TIM3);//获取下降沿的数据 //判读是否超出发生了溢出,计算高电平脉冲时间us if(TIM3CH3_CAPTURE_DOWNVAL<TIM3CH3_CAPTURE_UPVAL) { RC_CH[4] = 20000 - TIM3CH3_CAPTURE_UPVAL + TIM3CH3_CAPTURE_DOWNVAL; } else { RC_CH[4] = TIM3CH3_CAPTURE_DOWNVAL- TIM3CH3_CAPTURE_UPVAL; } TIM3CH3_CAPTURE_STA = 0; TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Rising); //设置为上升沿捕获 } } if(TIM_GetITStatus(TIM3, TIM_IT_CC4) == SET)//捕获1发生捕获事件 { TIM_ClearITPendingBit(TIM3, TIM_IT_CC4);//清除捕获1标志位 if(TIM3CH4_CAPTURE_STA == 0)//捕获到上升沿 { TIM3CH4_CAPTURE_UPVAL = TIM_GetCapture1(TIM3);//获取上升沿的数据 TIM3CH4_CAPTURE_STA = 1; //标记以捕获到了上升沿 TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Falling);//设置为下降沿捕获 } else //捕获到下降沿 (已经捕获到一个完整的高电平脉冲！) { TIM3CH4_CAPTURE_DOWNVAL = TIM_GetCapture1(TIM3);//获取下降沿的数据 //判读是否超出发生了溢出,计算高电平脉冲时间us if(TIM3CH4_CAPTURE_DOWNVAL<TIM3CH4_CAPTURE_UPVAL) { RC_CH[5] = 20000 - TIM3CH4_CAPTURE_UPVAL + TIM3CH4_CAPTURE_DOWNVAL; } else { RC_CH[5] = TIM3CH4_CAPTURE_DOWNVAL- TIM3CH4_CAPTURE_UPVAL; } TIM3CH4_CAPTURE_STA = 0; TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Rising); //设置为上升沿捕获 } } }[/mw_shl_code]

正点原子

建议你先搞定一个通道，比如CH3。
再高通道CH4，等两个通道都正常后，再融合。