一次读取总线上多个ds18b20的序列号.doc

/main.c/*一次读取多个DS18B20的序列号,序列号存放在数组tablenumber8中;*/#include ds18b20.hvoid main() get_rom(); while(1); /ds18b20.c#include uchar rom64; /64位序列号缓存区uchar tablenumber8;/序列号存放数组uchar numnumber-1; /*定时器延时函数*/void DELAY_US(uint time)time-;void wr_ds18b20(uchar byte) uchar i; for(i=0;ii)&0x01) SET_DQ; else CLR_DQ; DELAY_US(50); SET_DQ; DELAY_US(10); /*读取总线上两位数据*/uchar rd_two_bits() uchar i,Data=0x00; for(i=0;i=1; CLR_DQ; DELAY_US(5); SET_DQ; DELAY_US(8); if(DQ) Data|=0x02; DELAY_US(45); SET_DQ; return Data;/*向总线上写一位数据*/void wr_one_bit(uchar Data) CLR_DQ; DELAY_US(5); if(Data&0x01) SET_DQ; else CLR_DQ; DELAY_US(50); SET_DQ; DELAY_US(10);/*读多个DS18B20序列号的函数*/void get_rom() uchar i,j,flag,rd_data,temp=0x00,pointer=0x01; for(i=0;inumber;i+) flag=init_ds18b20(); if(flag) wr_ds18b20(0xf0); for(j=0;j=1; rd_data=rd_two_bits(); if(rd_data=0x01) temp|=0x80; romj=1; wr_one_bit(1); else if(rd_data=0x02) temp&=0x7f; romj=0; wr_one_bit(0); else if(rd_data=0x00) if(jnumpointer-1) numpointer+=j; temp&=0x7f; romj=0; wr_one_bit(0); else if(jnumpointer-1) temp=(romj7)|(temp&0x7f); romj=romj; wr_one_bit(romj); else if(j=numpointer-1) temp|=0x80; romj=1; pointer-; wr_one_bit(1); if(j+1)%8)=0) tablei(j+1)/8-1=temp; uchar init_ds18b20() CLR_DQ; DELAY_US(500); SET_DQ; DELAY_US(50); if(!DQ) DELAY_US(400);return 1; else DELAY_US(400);return 0;/ds18b20.h#ifndef _ds18b20_h#define _ds18b20_h#includesbit DQ=P10;#define CLR_DQ DQ=0;#define SET_DQ DQ=1;#define uchar unsigned char#define uint unsigned int#define number 2/定义总线上ds18b20的个数extern uchar rom64; /64位序列号缓存区extern uchar tablenumber8;/序列号存放数组extern uchar numnumber-1; extern void DELAY_US(uint time);extern void wr_ds18b20(uchar byte);extern uchar rd_ds18b20();extern uchar rd_two_bits();