protuesDS18B20仿真.doc

程序 代码#include #include #define uint unsigned int#defineuchar unsigned char#define nops(); _nop_();_nop_();_nop_();_nop_();sbit DQ=P30;uchar code led = 0x3f,0x06,0x5b,0x4f, 0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71 ;uchar code leddg = 0xbf,0x86,0xdb,0xcf, 0xe6,0xed,0xfd,0x87, 0xff,0xef,0xf7,0xfc ;void display (double x); void delayms(uint z);void delay1(uint z);uint ds18b20();uchar reset18b20();void main () double a; while(1)a=ds18b20();display(a); /void delayms(uint z) /延时函数 uint x,y;for(x=z;x0;x-)for(y=110;y0;y-); /void delay1(uint z) while(-z); /void display (double x) /显示函数uint a,b,d,e; int c; double g,h; if (x=128)c=(int)x;/45 10.12 a=c/100;/提取个位，百位b=c%100/10;d=c%100%10;g=x-c;/0.119999 有误差/*if(int)(g*100)+1)-g*100)=0.0001 ) /判断下 消除误差g=g+0.01;d=(int)(g*10);h=10*g-d;e=(int)(h*10);*/ e=(int)(10*g); P2=0xfe;P0=leda;delayms(10);P2=0xfd;P0=ledb;delayms(10);P2=0xfb;P0=leddgd;delayms(10);P2=0xf7;P0=lede;delayms(10);else c=(int)(256-x);b=c/10;d=c%10;e=0; P2=0xfe;P0=0x40;delayms(10);P2=0xfd;P0=ledb;delayms(10);P2=0xfb;P0=leddgd;delayms(10);P2=0xf7;P0=lede;delayms(10);/ uchar reset18b20() /复位18B20 uchar a; DQ=1;_nop_();_nop_(); DQ=0;delay1(80);DQ=1;nops();a=DQ;delay1(20);return a ; / void write (uchar dat) /向18B20里写 uchar i;DQ=1;_nop_();for(i=0;i=1; / uchar read() /读取18b20 uchar i,dat=0;DQ=1;_nop_();for(i=0;i=1;DQ=1;nops();if(DQ)dat|=0x80;delay1(30);DQ=1;return dat; / uint ds18b20() /启动18B20温度传感器uint a,b;reset18b20();write(0xcc); /跳过ID地址write(0x44); /启动温度转换reset18b20();write(0xcc);write(0xbe