can any one explin me about this code to measure distance in mm using 3 pin ultrasonic sensor…plz…
#include<reg51.h>
#include<intrins.h>
#include<lcd_busy.h>
#define lcd_port P1
bit rec_flag=0;
bit data_flag=0;
void lcd_dispaly();
void int_char_con(void);
void serial_init();
unsigned char array[5],count=0,dis_count=0;
unsigned char rec=0;
unsigned int dis=0,rot_count=0,ror_flag=0,step=0;
unsigned int dis_array[10],direction_count=0,loop_count=0;
unsigned int THOUSANDS,HUNDREDS, TENS, UNITS, DISTANCE, TEMP_VAL;
////////////////////////////////
void main()
{
// buzzer=0;
lcd_init();
lcd_init();
serial_init();
serial_init();
message(0x80,”Ultrasonic target”);
delay(500);
init(0x01);
while(1)
{
if(data_flag==1)
{
ES=0;
rec_flag=0;
data_flag=0;
DISTANCE=array[1]*256+array[2];
lcd_dispaly();
delay(5);
count=0;
ES=1;
}
}
}
//////////////////////////
void serial_init()
{
SCON=0X50; //SM2 SM1 SM0 REN TB8 RB8 TI RI G C/T M1 M0 G C/T M1 M0
TMOD=0X20; //0010 0000 // 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0
TH1=0XFD; //9600
TR1=1;
EA=1;
ES=1;
}
////////////////////////////
void serial(void) interrupt 4
{
if(RI==1)
{
RI=0;
rec=SBUF;
if(rec==0xff)
{
rec_flag=1;
}
if(rec_flag==1)
{
array[count++]=SBUF;
if(count=
)
)data_flag=1;
}
}
}
/////////////////////////////////////////////
void lcd_dispaly()
{
int_char_con();
dis_count=0;
}
void int_char_con(void)
{
init(0x80);
THOUSANDS = DISTANCE/1000;//to get thousands num
TEMP_VAL = DISTANCE%1000;
HUNDREDS = TEMP_VAL/100; //to get hundreds num
TEMP_VAL %= 100;
TENS = TEMP_VAL/10; //to get tens num
UNITS = TEMP_VAL%10;
write_lcd(THOUSANDS+0x30);
write_lcd(HUNDREDS+0x30);
write_lcd(TENS+0x30);
write_lcd(UNITS+0x30);
}