ds18b20温度传感器

1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#includesbit 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 480usDQ = 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;2for (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 = datDelay(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3void 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temphtemp=(templ4)|(temphsbit DQ= P34;4int temperature ;void delay(int us) int s;for ( s=0; s=1;DQ=1;if(DQ) u|=0x8000;delay(4);return (u);void write(unsigned char ku)int i=0;for (i=0;i=1;6void 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=ls