51单片机超声波模块测距Prpteus仿真加keil源代码

#include <reg52.h> #include <intrins.h> #include "stdio.h" #define uchar unsigned char #define uint unsigned int #define out P0 sbit rs=P2^0; sbit rw=P2^1; sbit e=P2^2; sbit led=P2^3; sbit key=P2^4; sbit trig = P1^5; sbit echo = P1^6; void check_busy(void); void write_command(uchar com); void write_data(uchar dat); void LCD_initial(void); void string(uchar ad ,uchar *s); void lcd_test(void); void delay(uint); //主程序 void Delay20us() //@12.000MHz { unsigned char i; _nop_(); i = 7; while (--i); } void Time0Init() { TMOD &= 0xF0; //设置定时器模式 TMOD |= 0x01; TH0 = 0; TL0 = 0; } void startHC() { trig=0; trig = 1; Delay20us(); trig = 0; } void main(void) { double time; double dis; unsigned char buf[10]; Time0Init(); LCD_initial(); while(1) { startHC(); while(echo==0); TR0=1; while(echo==1); TR0=0; time=TH0 * 256 + TL0; TH0=0; TL0=0; dis=time*0.017; string(0x80,"distance is :"); sprintf(buf,"%.1f",dis); string(0xC0,buf); // delay(1000); // write_command(0x01);//清屏 // delay(1000); } } //1ms延时程序 void delay(uint j) { uchar i=250; for(;j>0;j--) { while(--i); i=249; while(--i); i=250; } } //查忙程序 void check_busy(void) { uchar dt; do { dt=0xff; e=0; rs=0; rw=1; e=1; dt=out; }while(dt&0x80); e=0; } //写控制指令 void write_command(uchar com) { check_busy(); e=0; rs=0; rw=0; out=com; e=1; _nop_(); e=0; delay(1); } //写数据指令 void write_data(uchar dat) { check_busy(); e=0; rs=1; rw=0; out=dat; e=1; _nop_(); e=0; delay(1); } //屏幕初始化 void LCD_initial(void) { write_command(0x38);//8位总线,双行显示,5X7点阵字符 write_command(0x0F);//开整体显示，光标关，无黑块 write_command(0x06);//光标右移 write_command(0x01);//清屏 delay(1); } //输出字符串 void string(uchar ad,uchar*s) { write_command(ad); while(*s>0) { write_data(*s++); delay(100); } }