51单片机超声波测距用lcd1602显示距离写个程序

以下是51单片机超声波测距用lcd1602显示距离的程序，供参考：

#include<reg52.h>
#include<intrins.h>

#define LCD_dat P0
sbit LCD_RS = P2^0;
sbit LCD_RW = P2^1;
sbit LCD_EN = P2^2;

sbit Trig = P3^4;
sbit Echo = P3^5;

void delay_us(unsigned char us)
{
    while(us--)
    {
        _nop_();
        _nop_();
        _nop_();
        _nop_();
    }
}

void delay_ms(unsigned char ms)
{
    while(ms--)
    {
        delay_us(245);
        delay_us(245);
        delay_us(245);
        delay_us(245);
    }
}

void LcdWriteCmd(unsigned char cmd)
{
    LCD_RS = 0;
    LCD_RW = 0;
    LCD_dat = cmd;
    LCD_EN = 1;
    delay_us(5);
    LCD_EN = 0;
    delay_us(5);
}

void LcdWriteDat(unsigned char dat)
{
    LCD_RS = 1;
    LCD_RW = 0;
    LCD_dat = dat;
    LCD_EN = 1;
    delay_us(5);
    LCD_EN = 0;
    delay_us(5);
}

void LcdInit()
{
    LcdWriteCmd(0x38);
    LcdWriteCmd(0x0c);
    LcdWriteCmd(0x06);
    LcdWriteCmd(0x01);
}

void LcdClear()
{
    LcdWriteCmd(0x01);
}

void LcdSetCursor(unsigned char x, unsigned char y)
{
    if(y == 0)
        LcdWriteCmd(0x80 + x);
    else
        LcdWriteCmd(0x80 + 0x40 + x);
}

void LcdPrintStr(char *str)
{
    while(*str)
    {
        LcdWriteDat(*str++);
    }
}

unsigned int Ultrasonic()
{
    unsigned char i;
    unsigned int distance;

    Trig = 1;
    delay_us(10);
    Trig = 0;

    while(!Echo);
    TR0 = 1;
    while(Echo);
    TR0 = 0;
    distance = TH0 * 256 + TL0;
    distance = distance / 58;
    return distance;
}

void main()
{
    unsigned int distance;

    TMOD = 0x09;
    TH0 = 0;
    TL0 = 0;
    LcdInit();
    LcdClear();

    while(1)
    {
        distance = Ultrasonic();
        LcdSetCursor(0, 0);
        LcdPrintStr("Distance: ");
        LcdSetCursor(0, 1);
        LcdPrintStr("   ");
        LcdSetCursor(0, 1);
        LcdPrintStr(distance / 100 + '0');
        LcdPrintStr(distance % 100 / 10 + '0');
        LcdPrintStr(distance % 10 + '0');
        delay_ms(500);
    }
}

程序中使用了LCD1602库函数，并且通过超声波模块测量距离，并将结果显示在LCD1602上。在使用时，需要将Trig和Echo分别接到51单片机的P3.4和P3.5上，LCD1602的数据线接到P0口上，控制线分别接到P2.0、P2.1、P2.2上即可。