51-MCU Project: Range Finder

This my MCU project for my MCU course last term. I spend a lot of time on it and I like it because it is simple but cool.

The CPU is MC89S51. It is an automatic speed control and alarm system based on the ultrasonic ranging. Since it can display the distance on the LCD screen, I call it Range Finder.

The whole working process is:
1. setting the alarm range x1
2. setting the speed control range x2
3. turn on the switch
4. the ultrasonic ranging system would send a signal to the CPU to tell how long it would take for the sound to go to the nearest obstacle in the front and return back
5. the CPU would calculate the distance to the nearest obstacle which is x
6. if x1 > x, the green LED lights
else, the red LED lights and the buzzer rings
7. if x2 > x, the motor works in high speed
else, the motor works in low speed
8. the alarm range x1, the speed and the distance x would be displayed on the LCD screen

It has six modules as a whole in this system:
1the MCU minimum system
2) the ultrasonic ranging module
3) LCD1602 module
4) alarm module
5) DC motor module

the schematic:

experiment:

finished:

And I share my code here, the IDE is Keil4.
I had some Chinese annotation on it since it is required in this course.

^?Download sourceCode.txt

 
#include <AT89x51.H>		//
#include <intrins.h>
#define uchar unsigned char 
#define  RX  P2_0 //echo 
#define  TX  P2_1 //trig
#define LCM_RW  P2_6 //LCD
#define LCM_RS  P2_5
#define LCM_E   P2_7
#define LCM_Data  P0
#define Busy    0x80 //LCMBusy
 
#define led1 P1_4   //LEDLED
#define led2 P1_2   //LEDLED
#define buzzer P2_2 //
 
#define dianji P1_7 //I/O
#define ctrkey P3_6 //
#define ctrkey2 P3_7 
 
void LCMInit(void);//LCD
void DisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData);//LCD
void DisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData);//LCD
void Delay5Ms(void);//5
void Delay400Ms(void);//400
void Decode(unsigned char ScanCode);
void WriteDataLCM(unsigned char WDLCM);//LCD1602
void WriteCommandLCM(unsigned char WCLCM,BuysC);//LCD
 
unsigned char num = 0,gao_num = 1,di_num = 3; //
unsigned char keyv = 0;  //
 
unsigned char ReadStatusLCM(void);
unsigned char code Range[] = "==RangeFinder==";
unsigned char code Rangex[5][20] = {"L=025","L=050","L=100","L=150"}; //LCD1602
unsigned char code SpeedH[] = " SpeedHigh"; //
unsigned char code SpeedL[] = " Speed_Low"; //
unsigned char code ASCII[13] = "0123456789.-M";
unsigned char code table[]="Distance:000.0cm";//
unsigned char code table1[]="!!! Out of range";//
 
unsignedint  time=0;
unsigned long S=0;
unsigned int  limit=250;   //mm
bit  flag =0;
unsigned char disbuff[4]={ 0,0,0,0,};
 
/********************LCD************************************/
//
voidWriteDataLCM(unsigned char WDLCM) 
{
	ReadStatusLCM(); //
	LCM_Data = WDLCM;
	LCM_RS = 1;
	LCM_RW = 0;
	LCM_E = 0; 
	LCM_E = 0; //
	LCM_E = 1;
}
 
//
void WriteCommandLCM(unsigned char WCLCM,BuysC) //BuysC0
{
	if (BuysC) ReadStatusLCM(); //
	LCM_Data = WCLCM;
	LCM_RS = 0;
	LCM_RW = 0;	
	LCM_E = 0;
	LCM_E = 0;
	LCM_E = 1;	
}
 
//
unsigned char ReadStatusLCM(void)
{
	LCM_Data = 0xFF; 
	LCM_RS = 0;
	LCM_RW = 1;
	LCM_E = 0;
	LCM_E = 0;
	LCM_E = 1;
	while (LCM_Data& Busy); //
	return(LCM_Data);
}
 
void LCMInit(void) //LCM
{
	LCM_Data = 0;
	WriteCommandLCM(0x38,0); //
	Delay5Ms(); 
	WriteCommandLCM(0x38,0);
	Delay5Ms(); 
	WriteCommandLCM(0x38,0);
	Delay5Ms(); 
 
	WriteCommandLCM(0x38,1); //,
	WriteCommandLCM(0x08,1); //
	WriteCommandLCM(0x01,1); //
	WriteCommandLCM(0x06,1); // 
	WriteCommandLCM(0x0c,1); // 
}
 
//
voidDisplayOneChar(unsigned char X, unsigned char Y, unsigned char DData)
{
	Y &= 0x1;
	X &= 0xF;         //X15Y1
	if (Y) X |= 0x40; //+0x40;
	X |= 0x80;        //
	WriteCommandLCM(X, 1); //
	WriteDataLCM(DData);   //
}
 
//
voidDisplayListChar(unsigned char X, unsigned char Y, unsigned char code *DData)
{
	unsigned char ListLength;
 
ListLength = 0;
	Y &= 0x1;
	X &= 0xF;                      //X15Y1
	while (DData[ListLength]>0x19) //
		{
			if (X <= 0xF)          //X0xF
				{
					DisplayOneChar(X, Y, DData[ListLength]); //
					ListLength++;
					X++;
				}
		}
}
 
//5ms
void Delay5Ms(void)
{
	unsignedintTempCyc = 5552;
	while(TempCyc--);
}
 
//400ms
void Delay400Ms(void)
{
	unsigned char TempCycA = 5;
	unsignedintTempCycB;
	while(TempCycA--)
		{
			TempCycB=7269;
			while(TempCycB--);
		};
}
/*************************************************************/
void delay(uchari)        //
{
ucharj,k;
for(j=i;j>0;j--)
for(k=125;k>0;k--);
}
void key ()                //
{
   if(ctrkey==0)		   //
   {
     delay(5);             //
	if(ctrkey == 0)
	 {
keyv ++;
if(keyv>= 4)
keyv = 3;
switch(keyv)
         {
case 0:
           limit = 250;  //25cm
break;
case 1:
           limit = 500;  //50cm
break;
case 2:
           limit = 1000; //100cm
break;
		case 3:
		   limit = 1500; //150m
break;
		 }  
		 while(ctrkey == 0);//
	 }
   }
   if(ctrkey2 == 0)		    //
   {
delay(5);
	if(ctrkey2 == 0)
	 {
		if(keyv == 0);
		else
		keyv --;
switch(keyv)
         {
case 0:
           limit = 250;  //25cm
break;
case 1:
           limit = 500;  //50cm
break;
case 2:
           limit = 1000; //100cm
break;
		case 3:
		   limit = 1500; //150m
break;
		 }  
		 while(ctrkey2 == 0);//
	 }	
   }
}
 
/********************************************************/
 
void dispose()      //
{
switch(num)
  {
case 0:
	gao_num=1;     //PWM1
	di_num=3;      //PWM3
	break;
case 1:
	gao_num=1;
	di_num=3;      //
	break;
  }
}
void qudong()       //
{
unsigned char i;
if(di_num!=0)
  {
for(i=0;i<di_num;i++)
	{
	dianji=0;      //PWM
	delay(5);   
	}
  }
 
for(i=0;i<gao_num;i++)
  {
dianji=1;    //PWM
	delay(5);
  }
}
 
/********************************************************/
voidConut(void)
	{
	 time=TH0*256+TL0;//
	 TH0=0;
	 TL0=0;	
	 S=(time*1.7)/10;         //340/2 * 1000 / 1M 1.7mm
     if(S <= limit)           //
     {
      led1 = 1;
      led2 = 0;
buzzer = 0;
num = 0;
DisplayListChar(5, 0, SpeedL);
	 }
     else                   //
     {
      led1 = 0;
      led2 = 1; 
      P3_0 = 0;//??
buzzer = 1;
num = 1;
DisplayListChar(5, 0, SpeedH);
     }
dispose();
qudong();              //
     if((S>=3000)||flag==1) //2m
	 {	
buzzer = 1;
	flag=0;
DisplayListChar(0, 0, Rangex[keyv]);
DisplayListChar(5, 0, SpeedH);
DisplayListChar(0, 1, table1);
	 }
	 else                   //
	 {
disbuff[0]=S%10;
	disbuff[1]=S/10%10;
	disbuff[2]=S/100%10;
	disbuff[3]=S/1000;
DisplayListChar(0, 0, Rangex[keyv]);
if(S <= limit)
      {
DisplayListChar(5, 0, SpeedL);
	  }
else
      {
DisplayListChar(5, 0, SpeedH);
      }
DisplayListChar(0, 1, table);
	DisplayOneChar(9, 1, ASCII[disbuff[3]]);
	DisplayOneChar(10, 1, ASCII[disbuff[2]]);	
	DisplayOneChar(11, 1, ASCII[disbuff[1]]);
DisplayOneChar(12, 1, ASCII[10]);
	DisplayOneChar(13, 1, ASCII[disbuff[0]]);
	 }
	}
/********************************************************/
void zd0() interrupt 1 		 //T0,
{                            //RX
      flag=1;			     //
	  RX=0;
}
/********************************************************/
void  StartModule() 		         //
{
	  TX=1;			                 //trig
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_();
	  _nop_(); 
	  _nop_(); 
	  _nop_(); 
	  _nop_();
	  TX=0;//
}
/********************************************************/ 
voidTimer_Count(void)
{
	TR0=1;			    //
    while(RX);			//RX1TH0,TL0flag
    TR0=0;				//RX=0
Conut();			//
}
/*********************************************************/
void main(void)
{
unsignedintvalA;
unsignedinti;
	Delay400Ms();   //LCM
	LCMInit();      //LCM
	Delay5Ms();     //
    led1 = 0;
    led2 = 0;
	buzzer = 1;
DisplayListChar(0, 0, Range);
	DisplayListChar(0, 1, table);
for(i = 0; i< 10; i ++)
    {
Delay400Ms();
    }
    TMOD=0x01;     //T01GATE=1
dianji = 0;
    EA=1;          //
    TH0 = 0;
	TL0 = 0;
    ET0=1;         //T0		
	while(1)
	  {
		RX=1;
	StartModule();//10us
dianji = 0;
for(valA=7510;valA>0;valA--)
	    {
	       if(RX==1)//
		   {
		Timer_Count();
           }
key();
        }
	  }
}

Markdown	Result
text	text
text	text
*text*	text
`code`	`code`
~~~ more code ~~~~	more code
[Link](http://www.example.com)	Link
* Listitem	Listitem
> Quote	Quote

51-MCU Project: Range Finder

Share this:

Related