51单片机超声波测距代码是多少？

1602液晶显示 的超声波模块程序
接口程序里边都有、、

#include
//#include
#include

#define uchar unsigned char
#define uint unsigned int

sbit lcdrs=P2^3;
sbit lcden=P2^2;
sbit trig=P2^0; //超声波发送
//sbit echo=P3^2; //超声波接受
//P0____________DB0-DB7
uchar dis[]="Disp_HC-SR04";
uchar num[]="0123456789";
uint distance;

void delay(uint z)
{
uint x,y;
for(x=z;x>0;x--)
for(y=121;y>0;y--);
}

void HC_init()
{
TMOD=0x09;
TR0=1;
TH0=0;TL0=0;
}

uint HC_jisuan()
{
uint dist,timer;
timer=TH0;
timer<<=8;
timer=timer|TL0;
dist=timer/53; //晶振11.0592MHz 距离cm=微秒us/58
return dist; //1个机器周期是12个时钟周期 timer*12/(58*11.0592)=timer/53
}

void HC_run()
{
uint tempH=0x00,tempL=0x00;
TH0=0;TL0=0;
trig=0;
trig=1;
delay(1);
trig=0;
while((TH0-tempH!=0||TL0-tempL!=0)||(TH0==0&&TL0==0))
{
tempH=TH0;
tempL=TL0;
}
delay(1);
}

void lcd_write_com(uchar com) //LCD写指令
{
lcdrs=0;
P0=com;
delay(1);
lcden=1;
delay(1);
lcden=0;
}

void lcd_write_data(uchar date) //LCD写数据
{
lcdrs=1;
P0=date;
delay(1);
lcden=1;
delay(1);
lcden=0;
}

void lcd_init() //LCD初始化
{
lcden=0;
lcd_write_com(0x38);
lcd_write_com(0x0c);
lcd_write_com(0x06);
lcd_write_com(0x01);
}

void lcd_display(uchar temp)
{
uint i;

lcd_write_com(0x82);
for(i=0;i<12;i++)
{
lcd_write_data(dis[i]);
}

lcd_write_com(0x80+0x41);
lcd_write_data('D');
lcd_write_data('i');
lcd_write_data('s');
lcd_write_data('t');
lcd_write_data('a');
lcd_write_data('n');
lcd_write_data('c');
lcd_write_data('e');
lcd_write_data(':');
lcd_write_data(num[temp/100]);
lcd_write_data(num[temp/10%10]);
lcd_write_data(num[temp%10]);
lcd_write_data('c');
lcd_write_data('m');
}

void main()
{
lcd_init();
HC_init();
while(1)
{
HC_run();
distance=HC_jisuan();
lcd_display(distance);
delay(200);
}
}