超聲波測距模組（LCD顯示）—基於51微控制器
#include <reg52.h>
#define uint unsigned int
#define uchar unsigned char
sbit Trig = P1^0; //控制端
sbit Echo = P1^1; //接收端
sbit dula = P2^6;
sbit wela = P2^7;
sbit RS = P3^5;
sbit RW = P3^6;
sbit EN = P3^4;
uchar table[] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
uchar table1[] = {0xbf,0x86,0xdb,0xcf,0xe6,0xed,0xfd,0x87,0xff,0xef};//帶小數點的數
void timer0_init()//定時器0，1的初始化
{
TMOD = 0x11;
TH0 = 0;
TL0 = 0;
TR0 = 1;
ET0 = 1;
TH1 = 0xaf;
TR1 = 1;
ET1 = 1;
EA = 1;
}
void DelayUs2x(uchar t)//大約延時t*2+5us
{
while(--t);
}
void delayMs(uchar x)
{
uint i,j;
for(i = x;i > 0;i--)
for(j = 100;j > 0;j--);
}
//判斷液晶忙，如果忙則等待
void delay(int z)
{
int x,y;
for(x=z;x>0;x--)
for(y=114;y>0;y--);
}
void Read_Busy()
{
uchar busy;
P0 = 0xff;
RS = 0;
RW = 1;
do
{
EN = 1;
busy = P0;
EN = 0;
}while(busy & 0x80);
}
//寫LCD1602命令一個位元組
void Write_Cmd(uchar cmd)
{
Read_Busy();//判斷忙
RS = 0;
RW = 0;
P0 = cmd;
EN = 1;
EN = 0;
}
//寫一個位元組資料
void Write_Dat(uchar dat)
{
Read_Busy();
RS = 1;
RW = 0;
P0 = dat;
EN = 1;
EN = 0;
}
uint distance,time;
void main()
{
timer0_init();
Trig = 0;
Echo = 0;
Write_Cmd(0x38);//設定16*2顯示
Write_Cmd(0x0f);//開顯示 顯示游標，游標閃爍
Write_Cmd(0x01);//清屏
while(1)
{
Write_Cmd(0x01);
Write_Cmd(0x06);
Write_Cmd(0x80|0x02);
Write_Dat((distance/1000)+'0');//將所算距離的每一位以字元形式輸出
Write_Dat(((distance/100)%10)+'0');
Write_Dat(((distance/10)%10)+'0');
Write_Dat('.');
Write_Dat((distance%10)+'0');
delay(10);
}
}
void timer0()interrupt 1
{
TH0 = 0;
TL0 = 0;
}
void timer1()interrupt 3{
Trig = 1;
DelayUs2x(5);//給至少10us的高電平訊號
Trig = 0;
while(Echo == 0);//等待高電平
TR0 = 1;
while(Echo);//等待低電平
P3 = 0xf0;
TR0 = 0;
time = TH0*256+TL0;//time為毫秒級時間
distance = (int)(time*0.017*10);//根據聲速為每秒三百四十米計算
TH0 = 0;
TL0 = 0;
}