51单片机超声波测距程序

#include #include

#define uchar unsigned char #define uint unsigned int #define ulong unsigned long

// sbit speaker =P2^4 ; sbit P1_0=P1^0;

data uchar testok;

uchar code LEDData[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90}; uchar a,b,c,d,i;

data ulong time;

void delay(uchar k) {

while(k--) {_nop_();} }

void delay1m(int x) {

int p,q;

for(p=0;p<=x;p++) { for(q=1;q<=120;q++); } }

display() {// a=1;b=2;c=3;d=4;

P0 = 0xFF; P2 |= 0xE0;

P2 &= 0x1F; P0 = LEDData[d]; P2 |= 0xE0; P2 &= 0x1F; P0 = 0x10; P2 |= 0xC0; P2 &= 0x3F;

delay1m(4); P0 = LEDData[c]; P2 |= 0xE0; P2 &= 0x1F; P0 = 0x20; P2 |= 0xC0; P2 &= 0x3F; delay1m(4); P0 = LEDData[b]; P2 |= 0xE0; P2 &= 0x1F;

P0 = 0x40; P2 |= 0xC0; P2 &= 0x3F; delay1m(4);

P0 = LEDData[a]; P2 |= 0xE0; P2 &= 0x1F;

P0 = 0x80; P2 |= 0xC0; P2 &= 0x3F; delay1m(4); }

void main(void) {

P0=0xff; P2=0xff;

TMOD=0x21; // IE=0x80;

testok=0;

EA=1; TH1=0xf2; TL1=0xf2; ET1=1; TR1=1; ET0=1;

// TH0=0x00; // TL0=0x00; // ET0=1; // TR0=1; // EX0=1; while(1) { if(testok==1) { time=time*1.72; time=time/100; // time=1234; a=time; /* time /=10; b=time; time /=10; c=time; time /=10; d=time; */

b=(time0-a)/10;

c=(time00-b*10-a)/100;

d=(time000-c*100-b*10-a)/1000; display(); TH1=0xf2; TL1=0xf2; ET1=1; TR1=1;

//

EX0=1; testok=0; }

// if (testok==2) // { a=b=c=d=0; // TH1=0xf2; // TL1=0xf2; // ET1=1; // TR1=1; //

// EX0=1; // testok=0; // } } }

void cs_r(void) interrupt 0 {

TR0=0; // ET0=0; EX0=0;

TR1=0; ET1=0; // EA=0; //speaker=0; testok=1;

time=TH0*256+TL0; }

void overtime(void) interrupt 1 { TR0=0; // ET0=0; EX0=0;

TR1=0; ET1=0; // EA=0; //speaker=0;

TH1=0xf2; TL1=0xf2; ET1=1; TR1=1; EX0=1; testok=0; }

void cs_s2(void) interrupt 3 { i++; if(i<6) { P1_0=!P1_0; }

else {

TR1=0; EX0=1; TH0=0x00; TL0=0x00; TR0=1; i=0; } }