使用stm32的捕获功能就是无法成功，求大神！

只看该作者 · 2012-12-13 18:37

这是自己写的一个加速度传感器的代码，但是使用stm32的捕获功能就是无法成功，求大神！
#include "Memsic2125.h"
#include <math.h>
#include "usart.h"
#define PI 3.1415926
#define TILT(a) a*180/PI
float Xmg,AngleX;
float Ymg,AngleY;
u16 Ta=0;    //Ta：X轴上升开始计数Ta=0
u16 Tb,Tc,Td; //Tb:X轴下降沿结束计数；Tc：Y轴的上升沿，Td：Y轴下降沿
u8 CaptureNumber = 0;
u16 Capture = 0;
u8 flag = 0;

void TIM3_Configuration(void)
{
   TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
   TIM_ICInitTypeDef TIM_ICInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
//TIM3捕获通道3（X轴）,4（Y轴）引脚设置为浮空输入
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 49999; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值    溢出一次25ms
TIM_TimeBaseStructure.TIM_Prescaler =36-1; //设置用来作为TIMx时钟频率除数的预分频值  72分频记一次数0.5us
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
/* Enables the Update event for TIM3 */
// TIM_UpdateDisableConfig(TIM4,ENABLE); //使能 TIM4 更新事件
/*配置输入捕获通道3-PB0(X)*/
TIM_ICInitStructure.TIM_Channel = TIM_Channel_3;                //通道选择
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;    //下降沿触发
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //管脚与寄存器对应关系
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;          //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 = 0x0;    //滤波设置，经历几个周期跳变认定波形稳定0x0～0xF
TIM_ICInit(TIM3, &TIM_ICInitStructure);             //根据参数配置TIM外设信息
/*配置输入捕获通道4-PB1(Y)*/
TIM_ICInitStructure.TIM_Channel = TIM_Channel_4;                //通道选择
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;    //上升沿触发
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //管脚与寄存器对应关系
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;          //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 = 0x0;    //滤波设置，经历几个周期跳变认定波形稳定0x0～0xF
TIM_ICInit(TIM3, &TIM_ICInitStructure);             //根据参数配置TIM外设信息

/* 使能TIM3 */
TIM_ClearITPendingBit(TIM3,TIM_IT_CC3|TIM_IT_CC4|TIM_IT_Update); //清溢出中断
TIM_ITConfig(TIM3,TIM_IT_CC3|TIM_IT_CC4,DISABLE);
TIM_Cmd(TIM3, DISABLE);
}

void Read_XYmg(void)
{
// u16 Ta,Tb,Tc,Td; //Ta：X轴上升开始计数，Tb:X轴下降沿结束计数；Tc：Y轴的上升沿，Td：Y轴下降沿
float T1x,T1y,T2;
float RadianX,RadianY;
TIM3->CNT = 0;  //计数器清零
TIM3->CCR3 = 0;
TIM3->CCR4 = 0;
flag = 0;
TIM3->DIER |=3<<3;
while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_0) == 1);
while(GPIO_ReadInputDataBit(GPIOB,GPIO_Pin_0) == 0);
TIM3->CR1 |= 1<<0; //enable TIM
while(!flag); //等待Tb,Tc,Td采样完成
T1x = (float)Tb;
T1y = (float)(Td-Tc);
T2 = (Td-((Td-Tc)/2))-(Tb/2); //T2 = [Td – ((Td – Tc)/2)] – [Tb/2]
Xmg = ((T1x/T2)-500)*8.0; //数据手册中公式推导
Ymg = ((T1y/T2)-500)*8.0;
RadianX = asin(Xmg*0.001); //XY弧度制
RadianY = asin(Ymg*0.001);
AngleX = TILT(RadianX); //XY角度值
AngleY = TILT(RadianY);
printf("%f\n",T1x);
}

void TIM3_IRQHandler(void)
{
TIM_ICInitTypeDef TIM_ICInitStructure;
if(TIM_GetITStatus(TIM3,TIM_IT_CC3) != RESET)
{
TIM_ClearITPendingBit(TIM3,TIM_IT_CC3);
Tb = TIM3->CCR3;
TIM3->CNT =0;
TIM3->DIER &= ~(1<<3);
}
if(TIM_GetITStatus(TIM3,TIM_IT_CC4) != RESET)
{
TIM_ClearITPendingBit(TIM3,TIM_IT_CC4);
if(CaptureNumber == 0)
   {
   Tc = TIM3->CCR4;
   CaptureNumber = 1;
   TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling;    //下降沿触发
   TIM_ICInit(TIM3, &TIM_ICInitStructure);
   }
   else if(CaptureNumber == 1)
   {
   Td = TIM3->CCR4;
   TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;    //上升沿触发
   TIM_ICInit(TIM3, &TIM_ICInitStructure);
   if (Td > Tc)
   {
      Capture = (Td - Tc);
   }
   else
   {
      Capture = ((49999 - Tc) + Td);
   }
   CaptureNumber = 0;
   TIM3->CNT =0;
   flag = 1;
   TIM3->DIER &= ~(1<<4);
   TIM3->CR1 &= ~(1<<0);
   }

}
}