STM32定时器输入捕获模式测频率

1、STM32定时器输入捕获模式测频率/第一步：GPIO初始化GPIOnitTypeDefGPIOnitStructure;TIM2通道1通道2PAO、PAI、PA2、PA3RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA/ENABLE);使用PAO.PAI.PA2、PA3做为上拉输入，用来测频率GPIOnitStructureGPIO_Pin二GPIO_Pin_0|GPIO_Pin_l|GPIO_Pin_2|GPIO_Pin_3;GPIOnitStructureGPIO_Mode=GPIOModeJPU;GPIOnitStructureGPIO_Speed=

2、GPIO_Speed_2MHz;GPIOJnit(GPIOAz&GPIOJnitStructure);/第二步：中断向虽初始化/NVIC配置NVIC_lnitTypeDefNVICJnitStructure;NVICJnitStructure.NVICJRQChannel=TIM2RQn;NVICJnitStructure.NVICJRQChannelPreemptionPriority=1;NVICJnitStructure.NVICJRQChannelSubPriority=0;NVICJnitStructure.NVICJRQChannelCmd=ENABLE;NVIC_lnit(&NV

3、ICnitstructure);/第三步：定时器初始化测频率配置，捕获两个上升沿，计算频率voidTIM2_Freq_Config(void)TIM_TimeBaselnitTypeDefTIMTimeBaseStructure;TIMClnitTypeDefTIMClnitStructure;TIM_OCInitTypeDefTlM_OCInitStructure;RCC_APBlPeriphClockCmd(RCC_APBlPeriph_TIM2,ENABLE);/TIM2clockenableTIM_Delnit(TIM2);/*TIM2时钟配置*7TIM_TimeBaseStructu

4、re.TIM_Prescaler=(uintl6J)(72000000/2000000)1;预分频(时钟分频)72M/2M以2MHZ计数TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;向上计数TIM_TimeBaseStructure.TIM_Period=65535;装载值TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;TIM_TimeBaseStructure.TIM_RepetitionCounter=0 x0;TIM_TimeBaselnit(TIM2z&TIM_

5、TimeBaseStructure);TIMClnitStructure.TIMCPolarity=TIMCPolarity_Rising;上升沿触发TIMClnitStructure.TIMCPrescabr=TIMCPSC_DIV1;TIMClnitStructure.TIMCSelection=TIMCSelectionDirectTI;管脚与寄存器对应关系输入预分频。总思是控制在多少个输入周期做一次捕获，如果输入的信号频率没有变，测得的周期也不会变。比如选择4分频，则每四个输入周期才做一次捕获，这样在输入信号变化不频繁的情况下，/可以减少软件被不断中断的次数。TIMClnitStruc

6、ture.TIMCFilter=0 x01;滤波设置，经历几个周期跳变认定波形稳定0 x0OxF/*TIM2的通道四设置为输入捕获模式*/TIMClnitStructure.TIM_Channel=TIM_Channel_l;TIMClnit(TIM2,&TIMClnitStructure);TIMClnitStructure.TIM_Channel=TIM_Channel_2;TIMClnit(TIM2,&TIMClnitStructure);TIMClnitStructure.TIM_Channel=TIM_Channel_3;TIMClnit(TIM2,&TIMClnitStructur

7、e);TIMClnitStructure.TIM_Channel=TIM_Channel_4;TIMClnit(TIM2,&TIMClnitStructure);TIMTConfig(TIM2/TIMT_CC1,ENABLE)；使能中断TIMJTConfig(TIM2/TIMJT_CC2,ENABLE);TIMJTConfig(TIM2/TIMJT_CC3,ENABLE);TIMJTConfig(TIM2/TIMT_CC4,ENABLE)；TIM_Cmd(TIM2,ENABLE);启动TIM2/第四步：中断服务程序TIM2CH1/V4*J*J*记录各通道的捕获值捕获次数最终计算捕获公值_IOu

8、intl6_tTIM2IC_ReadValuel4,TIM2IC_ReadValue24;_IOuintl6_tTIM2CaptureNumber4;_IOuint32JTIM2Capture4;voidTIM2JRQHandler(void)u8i=0;if仃IM_GetlTStatus(TIM2/TIMT_Update)!=RESET)TIM_ClearlTPendingBit(TIM2/TIMJT_Update);elseif(TIM_GetlTStatus(TIM2/TIMT_CC1)=SET)/*ClearTIM3TIM2IC_ReadValuecompareinterruptpen

9、dingbit/TIM_ClearlTPendingBit(TIM2/TIMJTCCl);if(TIM2CaptureNumber0=0)/*GettheInputTIM2IC_ReadValuevalue*/TIM2IC_ReadValuel0=TIM_GetCapturel(TIM2);TIM2CaptureNumber0=1;elseif(TIM2CaptureNumber0=1)/*GettheInputTIM2IC_ReadValuevalue/TIM2IC_ReadValue20=TIM_GetCapturel(TIM2);/*TIM2IC_ReadValuecomputation

10、*/if(TIM2IC_ReadValue20TIM2IC_ReadValuel0)TIM2Capture0=(TIM2IC_ReadValue20-TIM2IC_ReadValuel0);elseTIM2Capture0=(OxFFFF-TIM2IC-ReadValuel0)+TIM2IC_ReadValue20);/*Frequencycomputation*/FrequencyO=2000000/TIM2Capture0;/计算频率=2MHz/时钟计数IM2CaptureNumber0=0;TIMTConfig(TIM2,TIMT_CC1,DISABLE);elseif(TIM_Getl

11、TStatus(TIM2,TIMT_CC2)=SET)/*ClearTIM3TIM2IC_ReadValuecompareinterruptpendingbit/TIM_ClearlTPendingBit(TIM2/TIMJT_CC2);if(TIM2CaptureNumber(l=0)/*GettheInputTIM2IC_ReadValuevalue*/TIM2IC_ReadValuell=TIM_GetCapture2(TIM2);TIM2CaptureNumberl=1;elseif(TIM2CaptureNumber(l=1)/*GettheInputTIM2IC_ReadValue

12、value*/TIM2IC_ReadValue2l=TIM_GetCapture2(TIM2);/*TIM2IC_ReadValuecomputation*/if(TIM2IC_ReadValue2lTIM2IC_ReadValuell)TIM2Capturel=(TIM2IC_ReadValue2l-TIM2IC_ReadValuell);elseTIM2Capturel=(OxFFFFTIM2IC-ReadValuell)+TIM2IC_ReadValue2l);/*Frequencycomputation*/Frequencyl=2000000/TIM2Capturel;/计算频率=2M

13、Hz/时钟计数TIM2CaptureNumberl=0;TIMJTConfig(TIM2zTIMT_CC2,DISABLE);elseif(TIM_GetlTStatus(TIM2,TIMJT_CC3)=SET)/*ClearTIM3TIM2IC_ReadValuecompareinterruptpendingbit*/TIM_ClearlTPendingBit(TIM2/TIMJT_CC3);if(TIM2CaptureNumber(2=0)/*GettheInputTIM2IC_ReadValuevalue*/TIM2IC_ReadValuel二TIM_GetCapture3(TIM2);

14、TIM2CaptureNumber2=1;elseif(TIM2CaptureNumber(2=1)/*GettheInputTIM2IC_ReadValuevalue*/TIM2IC_ReadValue2二TIM_GetCapture3(TIM2);/*TIM2IC_ReadValuecomputation*/if(TIM2IC_ReadValue22TIM2IC_ReadValuel2)TIM2Capture2=(TIM2IC_ReadValue22-TIM2IC_ReadValuel)；elseTIM2Capture2=(OxFFFFTIM2IC_ReadValuel2)+TIM2IC_

15、ReadValue22);/*Frequencycomputation*/Frequency2=2000000/TIM2Capture2;/计算频率=2MHz/时钟计数TIM2CaptureNumber2=0;TIMTConfig(TIM2,TIM_IT_CC3,DISABLE);elseif(TIM_GetlTStatus(TIM2,TIMJT_CC4)=SET)/*ClearTIM3TIM2IC_ReadValuecompareinterruptpendingbit*/TIM_ClearlTPendingBit(TIM2/TIMJT_CC4);if(TIM2CaptureNumber(3=0)/*GettheInputTIM2IC_ReadValuevalue*/TIM2IC_ReadValuel二TIM_GetCapture4(TIM2);TIM2CaptureNumber31=1;elseif(TIM2CaptureNumber3=1)/*GettheInputTIM2IC_ReadValuevalue*/TIM2IC_ReadValue2二TIM_GetCapture4(TIM2);/*TIM2IC_ReadValuecomputation*/if(TIM2IC_ReadValue23TIM2IC_Rea