AT89s51单总线多点式测温DS18B20于proteus仿真

#include<gg.h> void delay(int useconds) { int s; for (s=0; s<useconds;s++); } //////////////////////////////// unsigned char ow_reset(void) { unsigned char presence; DQ = 0; delay(29); DQ = 1; delay(3); presence = DQ; delay(25); return(presence); } ////////////////////////////// unsigned char read_bit(void) { unsigned char i; DQ = 0; DQ = 1; for (i=0; i<3; i++); return(DQ); } ////////////////////////// unsigned char ow_crc( unsigned char x) { dowcrc = dscrc_table[dowcrc^x]; return dowcrc; } //////////// void write_bit(char bitval) { DQ = 0; if(bitval==1) DQ =1; delay(5); DQ = 1; } ////////////////////////////// unsigned char read_byte(void) { unsigned char i; unsigned char value = 0; for (i=0;i<8;i++) { if(read_bit()) value|=0x01<<i; delay(6); } return(value); } ///////////////////////////////// void write_byte(char val) { unsigned char i; unsigned char temp; for (i=0; i<8; i++) { temp = val>>i; temp &= 0x01; write_bit(temp); } delay(5); } ////////////////////////// unsigned char Next(void) { unsigned char m = 1; unsigned char n = 0; unsigned char k = 1; unsigned char x = 0; unsigned char discrepMarker = 0; unsigned char g; unsigned char nxt; int flag; nxt = FALSE; dowcrc = 0; flag = ow_reset(); if(flag||doneFlag) { lastDiscrep = 0; return FALSE; } write_byte(0xF0); do { x = 0; if(read_bit()==1) x = 2; delay(6); if(read_bit()==1) x |= 1; if(x ==3) break; else { if(x>0) g = x>>1; else { if(m<lastDiscrep) g = ((ROM[n]&k)>0); else g = (m==lastDiscrep); if (g==0) discrepMarker = m; } if(g==1) ROM[n] |= k; else ROM[n] &= ~k; write_bit(g); m++; k = k<<1; if(k==0) { ow_crc(ROM[n]); n++; k++; } } }while(n<8); if(m<65||dowcrc) lastDiscrep=0; else { lastDiscrep = discrepMarker; doneFlag = (lastDiscrep==0); nxt = TRUE; } return nxt; } /////////////////////////////////////////// unsigned char First(void) //搜索rom { lastDiscrep = 0; doneFlag = FALSE; return Next(); } //////////////////////////////////////////// //发温度转换 void convert_t(uchar *rom) { uint i; ow_reset(); write_byte(0x55); for(i=0;i<8;i++) { write_byte(rom[i]); } write_byte(0x44); for(i=0;i<=500;i++) //延时等待转换完毕 { delay(100); } } //////////////////////////////////////读温度 void read_t(uchar *rom) { uchar i; ow_reset(); write_byte(0x55); for(i=0;i<8;i++) { write_byte(rom[i]); } write_byte(0xbe); for(i=0;i<9;i++) { temptr[i]=read_byte(); } } //////////////////////////////////////// ////////////////////////////////////////////////////////////