float Hcsr04GetLength(void ) { u32 t = 0; int i = 0; float lengthTemp = 0; float sum = 0; while(i!=5) { TRIG_Send = 1; delay_us(20); TRIG_Send = 0; while(ECHO_Reci == 0); OpenTimerForHc(); i = i + 1; while(ECHO_Reci == 1); CloseTimerForHc(); t = GetEchoTimer(); lengthTemp = ((float)t/58.0);//cm sum = lengthTemp + sum ; } lengthTemp = sum/5.0; return lengthTemp; } 将这个函数，改为标准库函数进行中断实现超声波测距

这个函数使用了延时函数和自定义的定时器函数，需要将其改为使用标准库函数进行中断实现。

以下是改写后的函数：

#include "stm32f10x.h"

#define TRIG_Send GPIO_Pin_0
#define ECHO_Reci GPIO_Pin_1

TIM_ICInitTypeDef  TIM_ICInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

void Hcsr04Init(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
    
    GPIO_InitStructure.GPIO_Pin = TRIG_Send;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    GPIO_InitStructure.GPIO_Pin = ECHO_Reci;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    TIM_ICStructInit(&TIM_ICInitStructure);
    TIM_ICInitStructure.TIM_ICFilter = 0x0F;
    TIM_ICInit(TIM2, &TIM_ICInitStructure);
    TIM_Cmd(TIM2, ENABLE);
}

float Hcsr04GetLength(void)
{
    uint32_t t = 0;
    int i = 0;
    float lengthTemp = 0;
    float sum = 0;

    while(i != 5)
    {
        TRIG_Send = 1;
        delay_us(20);
        TRIG_Send = 0;
        
        TIM_SetCounter(TIM2, 0);
        while(GPIO_ReadInputDataBit(GPIOA, ECHO_Reci) == 0);
        TIM_Cmd(TIM2, ENABLE);
        while(GPIO_ReadInputDataBit(GPIOA, ECHO_Reci) == 1);
        TIM_Cmd(TIM2, DISABLE);
        
        t = TIM_GetCapture1(TIM2);
        lengthTemp = ((float)t/58.0); // cm
        sum = lengthTemp + sum;
        
        i = i + 1;
    }
    
    lengthTemp = sum/5.0;
    
    return lengthTemp;
}

在这个改写后的函数中，使用了标准库函数来进行定时器和中断的配置，实现了超声波测距的功能。