#include????
#include?
typedef?unsigned?int?u16;	??//對數(shù)據(jù)類型進(jìn)行聲明定義
#define?uint?unsigned?int
#define?uchar?unsigned?char
sbit?rs=P2^6;????????????//1602的數(shù)據(jù)/指令選擇控制線?
sbit?rw=P2^5;???????????//1602的讀寫控制線?
sbit?en=P2^7;??????????//1602的使能控制線?
sbit?trig=P1^0;??????//超聲波測距模塊Trig
sbit?echo=P1^1;?????//超聲波測距模塊Echo
sbit?beep=P1^5;	//?蜂鳴器連接端	
uchar?flag=1;?????????//觸發(fā)信號標(biāo)志位//
uchar?count;???????????//中斷累加變量
long?int?distance;????//測量所得距離
unsigned?char?code?table[?]={“0123456789“};?//定義字符數(shù)組顯示數(shù)字
/*------------------------------------------------
??????????????????延時函數(shù)
------------------------------------------------*/
void?delay（uint?n）???????????????????????????
{?
????uint?xy;??
????for（x=n;x>0;x--）?
????for（y=110;y>0;y--）;?
}?

/*---延時函數(shù)---*/
void?delay1（u16?i）
{
	while（i--）;	
}
	???
/*------------------------------------------------
??????????????????延時函數(shù)
------------------------------------------------*/
void?delayt（uint?x）
{
????uchar?j;
????while（x--?>?0）
????{
??????????????for（j?=?0;j?????????{
??????????;
????????}
????}
}

/*------------------------------------------------
????????????????1602寫命令函數(shù)?
------------------------------------------------*/
void?lcd_wcom（uchar?com）????????????
{?
????rs=0;????????????????//選擇指令寄存器?
????rw=0;???????????????//選擇寫?
????P0=com;????????????//把命令字送入P0?
????delay（5）;?????????//延時一小會兒，讓1602準(zhǔn)備接收數(shù)據(jù)?
????en=1;????????????//使能線電平變化，命令送入1602的8位數(shù)據(jù)口這點(diǎn)非常重要?
????en=0;?
}

/*------------------------------------------------
???????????????1602寫數(shù)據(jù)函數(shù)????
------------------------------------------------*/
void?lcd_wdat（uchar?dat）????????
{?
????rs=1;?????????????//選擇數(shù)據(jù)寄存器?
????rw=0;????????????//選擇寫?
????P0=dat;?????????//把要顯示的數(shù)據(jù)送入P0?
????delay（5）;??????//延時一小會兒，讓1602準(zhǔn)備接收數(shù)據(jù)也就是檢測忙信號，這點(diǎn)非常重要。
????en=1;?????????//使能線電平變化，數(shù)據(jù)送入1602的8位數(shù)據(jù)口?
????en=0;?
??}?

/*------------------------------------------------
????????????????1602初始化函數(shù)??????
------------------------------------------------*/
void?lcd_init（）??????????????
{?
????lcd_wcom（0x38）;???????//8位數(shù)據(jù)，雙列，5*7字形??，用到功能設(shè)定指令?????
????lcd_wcom（0x0c）;??????//開啟顯示屏，關(guān)光標(biāo)，光標(biāo)不閃爍，用到顯示開關(guān)控制指令?
????lcd_wcom（0x06）;?????//顯示地址遞增，即寫一個數(shù)據(jù)后，顯示位置右移一位，用到了寫入模式設(shè)置指令
????lcd_wcom（0x01）;????//清屏，用到了清屏指令
}

/*------------------------------------------------
??????????????1602顯示固定字符函數(shù)??????
------------------------------------------------*/
void?lcd_xianshi（）??????????????
{?
????lcd_wcom（0x40+0x40）;
????????lcd_wdat（‘D‘）;
????????lcd_wdat（‘i‘）;
????????lcd_wdat（‘s‘）;
????????lcd_wdat（‘t‘）;
????????lcd_wdat（‘a(chǎn)‘）;
????????lcd_wdat（‘n‘）;
????????lcd_wdat（‘c‘）;
????????lcd_wdat（‘e‘）;
????????lcd_wdat（‘:‘）;
????????lcd_wcom（0x40+0x4c）;
????????lcd_wdat（‘.‘）;
????????lcd_wcom（0x40+0x4e）;//單位是厘米//	?0x40表示第一排顯示0x80表示第二排顯示
????????lcd_wdat（‘c‘）;
????????lcd_wdat（‘m‘）;
}


/*------------------------------------------------
定時器0初始化，用于計(jì)算響應(yīng)信號時間
------------------------------------