很久前测试过没问题，应该绝大部分来源于网络，供大家参考，后面会发简单的可以直接拿来用的自己瞎写的一看就明白的ds18b20库
#include <reg52.h>#include <intrins.h>#define uint unsigned int#define uchar unsigned char#define delayNOP() {_nop_();_nop_();_nop_();_nop_();}sbit DQ = P2^2;sbit LCD_RS = P3^5;//sbit LCD_RW = P2^4;sbit LCD_EN = P3^4;uchar code Temp_Disp_Title[]={"Current Temp : "};uchar Current_Temp_Display_Buffer[]={" TEMP: "};uchar code Temperature_Char[8] = {0x0c,0x12,0x12,0x0c,0x00,0x00,0x00,0x00};uchar code df_Table[]={0,1,1,2,3,3,4,4,5,6,6,7,8,8,9,9};uchar CurrentT = 0;uchar Temp_Value[]={0x00,0x00};uchar Display_Digit[]={0,0,0,0};bit DS18B20_IS_OK = 1;void DelayXus(uint x){uchar i;while(x--){for(i=0;i<200;i++);}}void Write_LCD_Command(uchar cmd){LCD_RS = 0;LCD_EN = 0;_nop_();_nop_();P0 = cmd;delayNOP();LCD_EN = 1;delayNOP();LCD_EN = 0;}void Write_LCD_Data(uchar dat){LCD_RS = 1;LCD_EN = 0;P0 = dat;delayNOP();LCD_EN = 1;delayNOP();LCD_EN = 0;}void LCD_Initialise(){Write_LCD_Command(0x01);DelayXus(5);Write_LCD_Command(0x38);DelayXus(5);Write_LCD_Command(0x0c);DelayXus(5);Write_LCD_Command(0x06);DelayXus(5);}void Set_LCD_POS(uchar pos){Write_LCD_Command(pos|0x80);}void Delay(uint x){while(--x);}uchar Init_DS18B20(){uchar status;DQ = 1;Delay(8);DQ = 0;Delay(90);DQ = 1;Delay(8);DQ = 1;return status;}uchar ReadOneByte(){uchar i,dat=0;DQ = 1;_nop_();for(i=0;i<8;i++){DQ = 0;dat >>= 1;DQ = 1;_nop_();_nop_();if(DQ)dat |= 0X80;Delay(30);DQ = 1;}return dat;}void WriteOneByte(uchar dat){uchar i;for(i=0;i<8;i++){DQ = 0;DQ = dat& 0x01;Delay(5);DQ = 1;dat >>= 1;}}void Read_Temperature(){if(Init_DS18B20()==1)DS18B20_IS_OK=0;else{WriteOneByte(0xcc);WriteOneByte(0x44);Init_DS18B20();WriteOneByte(0xcc);WriteOneByte(0xbe);Temp_Value[0] = ReadOneByte(); Temp_Value[1] = ReadOneByte();DS18B20_IS_OK=1;}}void Display_Temperature(){uchar i;uchar t = 150, ng = 0;if((Temp_Value[1]&0xf8)==0xf8){Temp_Value[1] = ~Temp_Value[1];Temp_Value[0] = ~Temp_Value[0]+1;if(Temp_Value[0]==0x00)Temp_Value[1]++;ng = 1;}Display_Digit[0] = df_Table[Temp_Value[0]&0x0f];CurrentT = ((Temp_Value[0]&0xf0)>>4) | ((Temp_Value[1]&0x07)<<4);Display_Digit[3] = CurrentT/100;Display_Digit[2] = CurrentT%100/10;Display_Digit[1] = CurrentT%10;Current_Temp_Display_Buffer[11] = Display_Digit[0] + '0';Current_Temp_Display_Buffer[10] = '.';Current_Temp_Display_Buffer[9] = Display_Digit[1] + '0';Current_Temp_Display_Buffer[8] = Display_Digit[2] + '0';Current_Temp_Display_Buffer[7] = Display_Digit[3] + '0';if(Display_Digit[3] == 0)Current_Temp_Display_Buffer[7] = ' ';if(Display_Digit[2] == 0&&Display_Digit[3]==0)Current_Temp_Display_Buffer[8] = ' ';if(ng){if(Current_Temp_Display_Buffer[8] == ' ')Current_Temp_Display_Buffer[8] = '-';else if(Current_Temp_Display_Buffer[7] == ' ')Current_Temp_Display_Buffer[7] = '-';else Current_Temp_Display_Buffer[6] = '-';}Set_LCD_POS(0x00);for(i=0;i<16;i++){Write_LCD_Data(Temp_Disp_Title[i]); }Set_LCD_POS(0x40);for(i=0;i<16;i++){Write_LCD_Data(Current_Temp_Display_Buffer[i]); }Set_LCD_POS(0x4d);Write_LCD_Data(0x00);Set_LCD_POS(0x4e);Write_LCD_Data('C');}void main(){LCD_Initialise();Read_Temperature();Delay(50000);Delay(50000);while(1){Read_Temperature();if(DS18B20_IS_OK) Display_Temperature();DelayXus(100);}}
