基于ds18b20的温度系统

#include<reg51.h> #define uchar unsigned char sbit DQ=P3^7; sbit voice=P3^0; sbit light=P3^1; sbit din=P1^0; //MAX7221数据输入端 sbit cs=P1^1; //MAX7221片选输入端 sbit clk=P1^2; sbit key_rst=P1^5; sbit key_min=P1^6; sbit key_hour=P1^7; //sbit key_clr=P3^6; //unsigned int flag; unsigned int temp; unsigned char second; unsigned char minute; unsigned char hour; unsigned char dis[4]={0,0,0,0}; unsigned char led[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0xff,0xbf}; //分别为0-9,不显示，负号 unsigned char led1[10]={0x40,0x79,0x24,0x30,0x19,0x12,0x02,0x78,0x00,0x10}; //带小数点显示 uchar code dispcode[]={ 0x7e,0x30,0x6d,0x79, //’0’ ，’1’ ，’2’， ’3’ 0x33,0x5b,0x5f,0x70, //’4’ ，’5’， ’6’， ’7’ 0x7f,0x7b,0x01,0x00 //’8’， ’9’ ，’-’， 无显示 }; unsigned char str2[8]={" "}; void delay(unsigned int i) //如果i是unsigend char类型，则会出现错误结果 { while(i--); } void Init(void)//初始化 { //unsigned char flag=0; DQ = 0; //单片机将DQ拉低 delay(100); //精确延时 大于 480us小于960us DQ = 1; //拉高总线 delay(30); //flag=DQ; //稍做延时后 如果flag=0则初始化成功 flag=1则初始化失败 //delay(20); } unsigned char Read(void)//读字节 { unsigned char i=0; unsigned char dat = 0; for (i=8;i>0;i--) { DQ = 0; // 给脉冲信号 dat>>=1; DQ = 1; // 给脉冲信号 if(DQ) dat|=0x80; delay(5); } return(dat); } void Write(unsigned char dat)//写字节 { unsigned char i=0; for (i=8; i>0; i--) { DQ = 0; DQ = dat&0x01; delay(5); DQ = 1; dat>>=1; } } void Display(unsigned int temp) //显示程序 { if(temp<=0x0800) { temp>>=4; //右移4位，相当于乘0.0625，将温度化为十进制 temp*=10; //扩大10倍，显示一位小数 dis[0]=temp/1000; //千位 dis[1]=temp%1000/100; //百位 dis[2]=temp%1000%100/10; //十位 dis[3]=temp%1000%100%10; //个位 } else { temp=~temp; temp+=1; temp>>=4; dis[0]=0x0c; //负数 dis[1]=temp%100/10; //百位 dis[2]=temp%100%10; //十位 dis[3]=0; //个位 } P2=0x01; //先片选，在段选，反过来就不能正常显示 P0=led[dis[0]]; delay(200); delay(200); P2=0x02; P0=led[dis[1]]; delay(200); delay(200); P2=0x04; P0=led1[dis[2]]; delay(200); delay(200); P2=0x08; P0=led[dis[3]]; delay(200); delay(200); } void clr_alarm(void) { voice=0; light=1; } void set_alarm(void) { voice=1; light=0; } void alarm(int temp) { //if(flag==0) // { if(temp>1500) { set_alarm(); } else { voice=0; light=1; } // } } void Timer() interrupt 1 { static uchar numval=20; TH0=(65536-50000)/256; TL0=(65536-50000)%256; numval--; if(numval==0) { numval=20; second++; if(second==60) { second=0; minute++; if(minute==60) { minute=0; hour++; if(hour==24)hour=0; } } str2[0]=hour/10; str2[1]=hour%10; str2[3]=minute/10; str2[4]=minute%10; str2[6]=second/10; str2[7]=second%10; } } void Write_7221(uchar com,uchar da) { uchar temp,i,j; cs=0; //片选有效 clk=0; //时钟低 for (i=0;i<8;i++) //发送显示位置 { temp=com; if ((temp&(0x80>>i))!=0) //先发高位 依次到低位 din=1; else din=0; clk=1; //时钟高 上升沿锁数据 for (j=0;j<5;j++); clk=0; } for (i=0;i<8;i++) //发送数据 { temp=da; if ((temp&(0x80>>i))!=0) //先发高位 依次到低位 din=1; else din=0; clk=1; for (j=0;j<5;j++); clk=0; } cs=1; } /*******************MAX7221初始化********************/ void Init_MAX7221(void) { Write_7221(0x0c,0x01); //正常工作状态,关断模式 Write_7221(0x09,0x00); //译码选择，非BCD码 Write_7221(0x0a,0x0f); //亮度调节 Write_7221(0x0b,0x07); //显示位数 } void keyscan1(void) { if(key_rst==0) { hour=0; minute=0; second=0; } } void keyscan2() { if(key_min==0) { while(!key_min ); minute++; if(minute==60) { minute=0; } } } void keyscan3() { if(key_hour==0) { while(!key_hour); hour++; if(hour==24) { hour=0; } } } main() { unsigned char tl=0,th=0; clr_alarm(); Init_MAX7221(); hour=22; minute=33; second=2;TMOD=0x01; TH0=(65536-50000)/256; TL0=(65536-50000)%256; EA=1; ET0=1; TR0=1; while(1) { Write_7221(0x01,dispcode[str2[0]]); Write_7221(0x02,dispcode[str2[1]]); Write_7221(0x03,0x01); Write_7221(0x04,dispcode[str2[3]]); Write_7221(0x05,dispcode[str2[4]]); Write_7221(0x06,0x01); Write_7221(0x07,dispcode[str2[6]]); Write_7221(0x08,dispcode[str2[7]]); keyscan1(); keyscan2(); keyscan3(); Init(); Write(0xCC); // 跳过读序号列号的操作 Write(0x44); // 启动温度转换 delay(100); Init(); Write(0xCC); //跳过读序号列号的操作 Write(0xBE); //读取温度寄存器等 delay(100); tl=Read(); //读取温度值低位 th=Read(); //读取温度值高位 temp=th<<8; temp|=tl; Display(temp); alarm(temp); } }