求基于AT89C51单片机和DS18B20温度传感器.doc

求基于AT89C51单片机和DS18B20温度传感器、LCD1602液晶显示的数字温度程序#include reg51.h #include 18b20.h #define uchar unsigned char #define uint unsigned int uchar code table=Welcome To ;/初始化日期和星期 uchar code table1=Our System!;/初始化时间uchar code table2=Temperature is:;/初始化时间 /以下三个是定义LCD的引脚 sbit lcden=P22; sbit lcdwrite=P21; sbit lcdrs=P20; char wendu; /延时程序 void delay(uint z) uint x,y; for(x=z;x0;x-) for(y=110;y0;y-); /lcd的写指令void write_com(uchar com) lcdrs=0; lcden=0; P0=com; delay(5); lcden=1; delay(5); lcden=0; /lcd的写数据void write_data(uchar da) lcdrs=1; lcden=0; P0=da; delay(5); lcden=1; delay(5); lcden=0; /初始化void init() uchar num; lcdwrite=0; lcden=0; write_com(0x38); /16*2显示，5*7点阵，8位数据 write_com(0x0c);/显示开，关光标 write_com(0x06); /移动光标 write_com(0x01);/清除LCD的显示内容 write_com(0x80); for (num=0;num10;num+) write_data(tablenum); delay(5); write_com(0x80+0x40); for (num=0;num11;num+) write_data(table1num); delay(5); void write_wendu(uchar add, char da) uchar shi,ge; shi=da/10; ge=da%10; write_com(0x80+0x40+add); write_data(0x30+shi); write_data(0x30+ge); /主函数void main () uchar num; init(); delay(2000);delay(2000); delay(2000); write_com(0x01);/清除LCD的显示内容while(1) write_com(0x80); for (num=0;num15;num+) write_data(table2num); delay(5); wendu = ReadTemp( );/读取温度 write_wendu(2,wendu); 以上是主程序/*ds18b20子程序*/*ds18b20延迟子函数（晶振12MHz ）*/ #include sbit DQ=P12;#define uchar unsigned charvoid delay_18B20(unsigned int i) while(i-);/*ds18b20初始化函数*/void Init_DS18B20(void) unsigned char x=0; DQ = 1; /DQ复位 delay_18B20(8); /稍做延时 DQ = 0; /单片机将DQ拉低 delay_18B20(80); /精确延时 大于 480us DQ = 1; /拉高总线 delay_18B20(4); x=DQ; /稍做延时后 如果x=0则初始化成功 x=1则初始化失败 delay_18B20(20);/*ds18b20读一个字节*/ unsigned char ReadOneChar(void) uchar i=0; uchar dat = 0; for (i=8;i0;i-) DQ = 0; / 给脉冲信号 dat=1; DQ = 1; / 给脉冲信号 if(DQ) dat|=0x80; delay_18B20(4); return(dat);/*ds18b20写一个字节*/ void WriteOneChar(uchar dat) unsigned char i=0; for (i=8; i0; i-) DQ = 0; DQ = dat&0x01; delay_18B20(5); DQ = 1; dat=1; /*读取ds18b20当前温度*/ ReadTemp(void) float val; uchar temp_value,value; unsigned char a=0; unsigned char b=0; unsigned char t=0;Init_DS18B20(); WriteOneChar(0xCC); / 跳过读序号列号的操作 WriteOneChar(0x44); / 启动温度转换delay_18B20(100); / this message is wery important Init_DS18B20(); WriteOneChar(0xCC); /跳过读序号列号的操作 WriteOneChar(0xBE); /读取温度寄存器等（共可读9个寄存器） 前两个就是温度delay_18B20(1