STM32定时器输入捕获模式测频率

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1、STM32定时器输入捕获模式测频率嘿儿哈2015/06/18//第一步：GPIO初始化GPIO_InitTypeDefGPIO_InitStructure;//TIM2通道1通道2PA0、PA1、PA2、PA3RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);//使用PA0、PA1、PA2、PA3做为上拉输入，用来测频率GPIO_InitStructure.GPIO_Pin=GPIO_Pin_0

2、GPIO_Pin_1

3、GPIO_Pin_2

4、GPIO_Pin_3;GPIO_InitStructure

5、.GPIO_Mode=GPIO_Mode_IPU;GPIO_InitStructure.GPIO_Speed=GPIO_Speed_2MHz;GPIO_Init(GPIOA,&GPIO_InitStructure);//第二步：中断向量初始化NVIC_InitTypeDefNVIC_InitStructure;NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn;//NVIC配置NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;NVIC_InitStruc

6、ture.NVIC_IRQChannelSubPriority=0;NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;NVIC_Init(&NVIC_InitStructure);//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_TimeBaseInitTypeDefTIM_TimeBaseStructure;TIM_ICInitTypeDefTIM_ICInitStructure;TIM_OCInitTypeDefTIM_OCInit

7、Structure;RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);//TIM2clockenableTIM_DeInit(TIM2);/*TIM2时钟配置*/TIM_TimeBaseStructure.TIM_Prescaler=(uint16_t)(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_TimeBaseStr

8、ucture.TIM_Period=65535;//装载值TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;TIM_TimeBaseStructure.TIM_RepetitionCounter=0x0;TIM_TimeBaseInit(TIM2,&TIM_TimeBaseStructure);TIM_ICInitStructure.TIM_ICPolarity=TIM_ICPolarity_Rising;//上升沿触发TIM_ICInitStructure.TIM_ICPrescaler=TI

9、M_ICPSC_DIV1;TIM_ICInitStructure.TIM_ICSelection=TIM_ICSelection_DirectTI;//管脚与寄存器对应关系//输入预分频。意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。TIM_ICInitStructure.TIM_ICFilter=0x01;//滤波设置，经历几个周期跳变认定波形稳定0x0～0xF/*TIM2的通道四设置为输入

10、捕获模式*/TIM_ICInitStructure.TIM_Channel=TIM_Channel_1;TIM_ICInit(TIM2,&TIM_ICInitStructure);TIM_ICInitStructure.TIM_Channel=TIM_Channel_2;TIM_ICInit(TIM2,&TIM_ICInitStructure);TIM_ICInitStructure.TIM_Channel=TIM_Channel_3;TIM_ICInit(TIM2,&TIM_ICInitStructure);TIM_ICInitStructure.

11、TIM_Channel=TIM_Channel_4;TIM_ICInit(TIM2,&TIM_ICInitS