超声波测距程序

/*******超声波测距程序*******/#include #include#define uchar unsigned char#define uint unsigned intsbit rs = P2^4;sbit rw = P2^5;sbit en = P2^6;sbit tr = P3^2;                sbit ec = P1^0;  uint distance = 0;            uchar count;void delayms(uint x){   uint i,j;   for(i=x;i>0;i--)     for(j=110;j>0;j--);}void write_com(uchar com){   rs = 0;   rw = 0;   en = 0;   P0 = com;   delayms(2);   en = 1;   delayms(5);   en = 0;   delayms(2);}void write_dat(uchar dat){   rs = 1;   rw = 0;   en = 0;   P0 = dat;   delayms(2);   en = 1;   delayms(5);   en = 0;   delayms(2);}void Init_1602(){write_com(0x38);delayms(5);write_com(0x0c);delayms(5);write_com(0x06);delayms(5);write_com(0x01);delayms(5);}void Init_TIMER0(){TMOD = 0x01;    TL0 = 0x66;TH0 = 0xfc;       ET0 = 1;       EA = 1;        }void Init_mk(){tr =1;  ec = 1;count = 0;distance = 0;}void init_fs(){  ec= 1;_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();  ec = 0;}void jsdistance(){uint y;TR0 = 1;while(tr);TR0 = 0;y = TH0*256+TL0;y = y - 0xfc66;distance = y + 1000 * count;TL0 = 0x66;TH0 = 0xfc;delayms(30);distance = 0.340 * distance / 2;} void display(){  uchar qian,bai,shi,ge;  qian= (distance / 1000);  bai= (distance  / 100) % 10;  shi = (distance  / 10) % 10;  ge = distance  % 10;   write_com(0x80+0x40+4);  write_dat(0x30+qian);  write_dat(0x30+bai);   write_dat(0x30+shi);  write_dat('.');  write_dat(0x30+ge);  write_dat('C');             write_dat('M');   }void write_hz(uchar *p){   while(*p != 0)   write_dat(*p++);   delayms(500);}void main(){   rw = 0;Init_1602();Init_TIMER0();Init_mk();while(1){   init_fs();           while(tr == 0)                   {             ;         }   jsdistance();       display();   Init_mk();             delayms(10);        write_com(0x80);     write_hz("****distance****");       } }void TIMER0() interrupt 1{TF0 = 0;TL0 = 0x66;TH0 = 0xfc;count++;if(count == 18){  TR0 =0;   TL0 = 0x66;   TH0 = 0xfc;  count = 0;}}