DS18b20温度传感器.doc
【精品文档】如有侵权，请联系网站删除，仅供学习与交流DS18b20温度传感器.精品文档.最小的温度显示程序 -c51(2010-12-07 00:45:27) 转载标签： 杂谈分类： 51单片机 #include<reg52.h>#include<math.h>sbit DQ=P20;bit presence;unsigned char templ,temph;char array10=0x7e,0x48,0x3d,0x6d,0x4b,0x67,0x73,0x4c,0x7f,0x4f;void Delay(unsigned int num)/可定义延时 while( -num );bit Init_DS18B20(void) DQ = 1; /DQ复位 Delay(8); /稍做延时 DQ = 0; /单片机将DQ拉低 Delay(90); /精确延时大于 480us DQ = 1; /拉高总线 Delay(8); presence = DQ; /如果=0则初始化成功 =1则初始化失败 Delay(100); DQ = 1; return(presence); /返回信号，0=presence,1= no presenceunsigned int ReadOneChar(void)unsigned char i = 0;unsigned char dat = 0;for (i = 8; i > 0; i-) DQ = 0; / 给脉冲信号 dat >>= 1; /位右移 DQ = 1; / 给脉冲信号 等待传感器返回脉冲 if(DQ) dat |= 0x80; Delay(4); return (dat);void WriteOneChar(unsigned char dat) unsigned char i = 0; for (i = 8; i > 0; i-) DQ = 0; DQ = dat&0x01; Delay(5); DQ = 1; dat>>=1; void Read_Temperature(void) Init_DS18B20(); WriteOneChar(0xcc); / 跳过读序号列号的操作 WriteOneChar(0x44); / 启动温度转换 Init_DS18B20(); WriteOneChar(0xCC); /跳过读序号列号的操作 WriteOneChar(0xBE); /读取温度寄存器 templ = ReadOneChar(); /温度低8位 temph = ReadOneChar(); /温度高8位void main()float temp;char a; Init_DS18B20(); WriteOneChar(0xcc); WriteOneChar(0x44); / 启动温度转换 Init_DS18B20(); WriteOneChar(0xcc); WriteOneChar(0xbe); /读取温度寄存器 templ = ReadOneChar(); /温度低8位 temph = ReadOneChar(); /温度高8位 temph&=0x07; temp=(templ>>4)|(temph<<4); temp+=(templ&0x0f)*0.0625; a= temp/10; P1=arraya; a=temp-10*a; P0=arraya; /*DS18b20温度传感器p3.4作为数据传输口晶振：11.0592M*/#include<reg51.H>sbit DQ= P34;int temperature ;void delay(int us) int s;for ( s=0; s<us; s+);void rst(void)DQ = 1;delay(2);DQ = 0;delay(30); /精确延时 480960usDQ = 1;delay(8);unsigned int read(void)int i=0;unsigned int u=0;for (i=0;i<16;i+)DQ=0;u>>=1;DQ=1;if(DQ) u|=0x8000;delay(4);return (u);void write(unsigned char ku)int i=0;for (i=0;i<8;i+)DQ=0;DQ =ku&0x01;delay(3);DQ=1;ku>>=1;void read0(void)/int temperature ;unsigned int tp;unsigned int lsb;rst();write(0xCC);write(0x44);rst();write(0xCC);write(0xBE);tp=read();lsb=(unsigned int)(tp*6.25); /temperature=lsb/100;void main(void)while(1)read0(); /读温度子程序 读到的温度放在全局变量temperature 中可以直接显示这个的内容
