STM32超声波测距小问题

只看该作者 · 2013-6-7 17:00

我同时配置上升沿触发和下降沿触发，在上升沿的时候启动定时器，在下降沿的时候关闭定时器，求距离，但是目前是上升沿触发进不去中断呀，
代码如下：

/*超声波使能引脚定义*/
#define CHAOSHENGBO_1_H       GPIOA->BSRR = GPIO_Pin_11
#define CHAOSHENGBO_1_L       GPIOA->BRR  = GPIO_Pin_11
#define CHAOSHENGBO_2_H       GPIOA->BSRR = GPIO_Pin_12
#define CHAOSHENGBO_2_L       GPIOA->BRR  = GPIO_Pin_12
#define CHAOSHENGBO_3_H       GPIOA->BSRR = GPIO_Pin_13
#define CHAOSHENGBO_3_L       GPIOA->BRR  = GPIO_Pin_13

#define CHAOSHENGBO1_read_H    GPIOC->IDR  & GPIO_Pin_2
#define CHAOSHENGBO2_read_H    GPIOC->IDR  & GPIO_Pin_3
#define CHAOSHENGBO3_read_H    GPIOC->IDR  & GPIO_Pin_4
/*
********************************************************************************
** 函数名称： INIT_EXIT(void)
** 函数功能：外部中断初始化
** 输入：无
** 输出：无
** 返回：无
********************************************************************************
*/
void INIT_EXIT(void)
{

RCC->APB2ENR |= 0X00000001;                   // enable clock for Alternate Function
AFIO->EXTICR[0] &= 0xFFFF;                            // clear used pin
AFIO->EXTICR[0] |= (0xFFFF & 0x2222);          // set pin to use
AFIO->EXTICR[1] &= 0xFFFF;                            // clear used pin
AFIO->EXTICR[1] |= (0xFFFF & 0x0002);          // set pin to use

EXTI->IMR    |= ((1 << 0) & 0X0000000F);          // unmask interrupt
EXTI->EMR    |= ((1 << 0) & 0X00000000);          // unmask event
EXTI->RTSR    |= ((1 << 0) & 0X0000000F);          // set rising edge
EXTI->FTSR    |= ((1 << 0) & 0X00000000);          // set falling edge

EXTI->IMR    |= ((1 << 1) & 0X0000000F);          // unmask interrupt
EXTI->EMR    |= ((1 << 1) & 0X00000000);          // unmask event
EXTI->RTSR    |= ((1 << 1) & 0X0000000F);          // set rising edge
EXTI->FTSR    |= ((1 << 1) & 0X00000000);          // set falling edge

EXTI->IMR    |= ((1 << 2) & 0X0000000F);          // unmask interrupt
EXTI->EMR    |= ((1 << 2) & 0X00000000);          // unmask event
EXTI->RTSR    |= ((1 << 2) & 0X0000000F);          // set rising edge
EXTI->FTSR    |= ((1 << 2) & 0X0000000F);          // set falling edge

EXTI->IMR    |= ((1 << 3) & 0X0000000F);          // unmask interrupt
EXTI->EMR    |= ((1 << 3) & 0X00000000);          // unmask event
EXTI->RTSR    |= ((1 << 3) & 0X0000000F);          // set rising edge
EXTI->FTSR    |= ((1 << 3) & 0X0000000F);          // set falling edge

EXTI->IMR    |= ((1 << 4) & 0X0000000F);          // unmask interrupt
EXTI->EMR    |= ((1 << 4) & 0X00000000);          // unmask event
EXTI->RTSR    |= ((1 << 4) & 0X0000000F);          // set rising edge
EXTI->FTSR    |= ((1 << 4) & 0X0000000F);          // set falling edge

   NVIC->ISER[0] |= (1 << (EXTI0_IRQChannel & 0x1F)); // enable interrupt EXTI 0
   NVIC->ISER[0] |= (1 << (EXTI1_IRQChannel & 0x1F)); // enable interrupt EXTI 1
   NVIC->ISER[0] |= (1 << (EXTI2_IRQChannel & 0x1F)); // enable interrupt EXTI 2
   NVIC->ISER[0] |= (1 << (EXTI3_IRQChannel & 0x1F)); // enable interrupt EXTI 3
   NVIC->ISER[0] |= (1 << (EXTI4_IRQChannel & 0x1F)); // enable interrupt EXTI 4

  }

/*
********************************************************************************
** 函数名称： EXTI2_IRQHandler(void)
** 函数功能：右轮计数中断
** 输入：无
** 输出：无
** 返回：无
********************************************************************************
*/
void EXTI2_IRQHandler(void)
{
  if (EXTI->PR & (1<<2)) {                      // 是否是外部中断2
   if(CHAOSHENGBO1_read_H==1){
   //启动定时器
      count=0;
      TIM3->CNT=0;
      TIM_Cmd(TIM3, ENABLE); //开启时钟
}
   else{
   //关闭定时器
      TIM_Cmd(TIM3, DISABLE); //开启时钟
count=TIM3->CNT;
juli=(17/1000)*count;
if(juli<25)
      zhangai_qian=1;
else
      zhangai_qian=0;
}
EXTI->PR |= (1<<2);                         // 清除中断标志
  }
}