stm32f4 测上升沿个数

老爹爹 · 发表于 2018-3-12 16:45:38

本程序把PA0复用映射到TIM5，记录PA0口输入进去的方波中上升沿个数，但是实际结果中PA0没有接入信号仍有捕获中断，求各位大神指指路！！！！

本程序是改编原子哥例子程序而来，但是效果不佳，请各位帮忙看看！！！！
【timer.c】
void TIM5_CH1_Cap_Init(u32 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_ICInitTypeDef  TIM5_ICInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_Init(GPIOA,&GPIO_InitStructure);       //IO口复用映射为推完复用输出

GPIO_PinAFConfig(GPIOA,GPIO_PinSource0,GPIO_AF_TIM5);

TIM_TimeBaseStructure.TIM_Prescaler=psc;
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period=arr;
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;

TIM_TimeBaseInit(TIM5,&TIM_TimeBaseStructure);       //初始化定时器计时

//初始化TIM5的捕捉参数
  TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1;    //CC1S=01
  TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;    //上升沿捕获
  TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //通道1映射到TI1
  TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;    //不分频
  TIM5_ICInitStructure.TIM_ICFilter = 0x00;    //不滤波
  TIM_ICInit(TIM5, &TIM5_ICInitStructure);

  TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1,ENABLE);    //更新中断捕获中断

  TIM_Cmd(TIM5,ENABLE );

      NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority =0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);    //初始化中断参数

}
int count=0;
int ccount=0;
//中断服务函数
void TIM5_IRQHandler(void)
{
  if(TIM_GetITStatus(TIM5,TIM_IT_Update)==SET)    //检查是否更新中断
ccount=count;       //用于记录一次更新中断期间上升沿个数
else       // 捕获中断
count++;       //记录捕获中断个数
TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update);    //清除中断标志位
}

【main.c】
extern int count;
extern int ccount;
int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);       //中断优先级分组
delay_init(168);
uart_init(115200);

TIM5_CH1_Cap_Init(2000000-1,84-1);       //定时器两秒，记录两秒内上升沿个数
while(1)
{
if(ccount!=0)                                        //如果上升沿个数为0 则不用打印
{
printf("COUNT:%d “ ccount);       //打印上升沿个数
ccount=0;          //清空
count=0;
}
}
}