keil5运行hc-sr04超声波测距用lcd1602显示，用声光报警器报警代码

我可以为您提供以下参考代码：

#include <reg52.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <intrins.h>

typedef unsigned char uchar;
typedef unsigned int uint;

sbit ECHO = P3^2;
sbit TRIG = P3^3;
sbit buzz = P2^3;

void delay_us(uint us)
{
    while(us--)
    {
        _nop_();
    }
}

void delay_ms(uint ms)
{
    while(ms--)
    {
        delay_us(1000);
    }
}

void LcdWriteCom(uchar com)
{
    P0 = com;
    P2 &= ~0x01;
    _nop_();
    P2 |= 0x01;
    delay_us(100);
    P2 &= ~0x01;
}

void LcdWriteData(uchar dat)
{
    P0 = dat;
    P2 |= 0x04;
    _nop_();
    P2 |= 0x01;
    delay_us(100);
    P2 &= ~0x01;
}

void LcdInit()
{
    LcdWriteCom(0x38);
    delay_ms(5);
    LcdWriteCom(0x38);
    delay_ms(5);
    LcdWriteCom(0x38);
    delay_ms(5);
    LcdWriteCom(0x08);
    delay_ms(5);
    LcdWriteCom(0x01);
    delay_ms(5);
    LcdWriteCom(0x06);
    delay_ms(5);
    LcdWriteCom(0x0c);
    delay_ms(5);
}

void LcdShowChar(uchar X, uchar Y, uchar DData)
{
    if(Y==0)        LcdWriteCom(0x80+X);
    else if(Y==1)   LcdWriteCom(0xc0+X);
    else if(Y==2)   LcdWriteCom(0x94+X);
    else if(Y==3)   LcdWriteCom(0xd4+X);
    LcdWriteData(DData);
}

void LcdShowStr(uchar X, uchar Y, uchar *DData)
{
    while(*DData!='\0')
    {
        LcdShowChar(X, Y, *DData);
        X++;
        DData++;
    }
}

void beep(int freq, int time)
{
    int i, j;
    while(time--)
    {
        buzz = 1;
        for(i=0;i<freq;i++)
        {
            for(j=0;j<10;j++);
        }
        buzz = 0;
        for(i=0;i<freq;i++)
        {
            for(j=0;j<10;j++);
        }
    }
}

uint GetEchoLength()
{
    uint length = 0;
    TRIG = 1;
    delay_us(10);
    TRIG = 0;
    while(!(ECHO));
    while(ECHO)
    {
        delay_us(1);
        length++;
    }
    return length;
}

int main()
{
    uint distance;
    float dist;

    uchar s[16];

    LcdInit();
    LcdShowStr(0, 0, (uchar *)"Distance:");
    LcdShowStr(0, 1, (uchar *)"");
    LcdShowStr(12, 1, (uchar *)"cm");
    delay_ms(500);

    while(1)
    {
        distance = GetEchoLength();

        dist = (float)distance * 0.015; // 单位换算，计算距离

        LcdShowStr(0, 1, (uchar *)"    ");
        sprintf(s, "%.2f", dist);  // 转换为字符串并显示
        LcdShowStr(0, 1, s);

        if(dist < 10.0)  beep(1000, 200); // 距离小于10cm，报警
        delay_ms(500);               
    }

    return 0;
}

这是使用Keil5开发的，可以测量HC-SR04超声波传感器的距离，并将距离值显示在LCD1602上，在距离小于10cm时还会触发声光报警器。希望这能帮到你！