基于51单片机的DHT11数字温湿度计.docx

#include #include #define uchar unsigned char#define uint unsigned intuchar byte,SH,SL,WH,WL,CHECK,FLAG;sbit LCDRS=P32;sbit LCDEN=P33;/sbit LCDRW=P22;sbit BUS=P34;void delay(uchar ms) /精确1msuchar i,j;for(i=ms*5;i0;i-)for(j=100;j0;j-);void delay1() /约7us uchar i; for(i=3;i0;i-);/*LCD配置*/*bit check_busy()/检测busyuchar temp;bit BB;LCDRS=0;LCDRW=1;LCDEN=1;P0=temp;delay(5);LCDEN=0;BB=(bit)(temp&0x80);/检测D7是否为1，为1则忙return BB;*/void write_com(uchar com)/while(check_busy();/检测LCD是否忙delay(5);LCDRS=0;/LCDRW=0;LCDEN=0;P1=com;delay(5);LCDEN=1;delay(5);LCDEN=0;void write_data(uchar dat)/while(check_busy();/检测LCD是否忙delay(5);LCDRS=1;/LCDRW=0;LCDEN=0;P1=dat;delay(5);LCDEN=1;delay(5);LCDEN=0;void dis(uchar add,uchar dat)delay(10);write_com(add);/送地址delay(5);write_data(dat);/送数据delay(5);void init()FLAG=0;delay(50);write_com(0x38);_nop_();write_com(0x0c);_nop_();write_com(0x06);_nop_();write_com(0x80);_nop_();write_com(0x01);_nop_();TMOD=0X01;TH0=(65536-50000)/256;TL0=(65536-50000)%256;EA=1;ET0=1;TR0=1;/*DHT11*/void start()BUS=1; /起始总线为高电平_nop_();BUS=0;/主机拉低delay(25);/延时大于18msBUS=1;/主机拉高delay1();delay1();delay1();delay1();uchar receive_byte()uchar i,temp;for(i=0;i8;i+) while(!BUS);/检测50us低电平延时是否结束 delay1(); delay1(); delay1(); delay1(); temp=0;/2628us为数据“0” if(BUS=1) /70us为数据“1” temp=1; while(BUS);/检测数据高电平结束 byte=1; /数据存储在bite里，每次右移一位 byte|=temp;/bite右移空位补零，然后与temp进行或运算，赋值给bitereturn byte;void receive_data()uchar S_H,S_L,W_H,W_L,CHECK_;while(FLAG);/采集周期标志位start();BUS=1;/设定总线为输入状态while(BUS);/检测DHT响应低电平while(!BUS);/检测DHT拉高总线电平while(BUS);/检测80us后拉低电平S_H=receive_byte();S_L=receive_byte();W_H=receive_byte();W_L=receive_byte();CHECK_=receive_byte();/40bit数据while(BUS);delay1();delay1();delay1();delay1();delay1();delay1();delay1();delay1();delay1();/延时50usBUS=1; /总线经上拉电阻拉高CHECK=S_H+S_L+W_H+W_L;/校验运算if(CHECK=CHECK_)/校验SH=S_H-7;SL=S_L;WH=W_H-1;WL=W_L;CHECK_=CHECK;/*MAIN*/void main()init(); while(1)receive_data();/*湿度*/dis(0x80+0x01,D); dis(0x80+0x02,A);dis(0x80+0x03,M);dis(0x80+0x04,:);dis(0x80+0x06,SH/10+0x30);dis(0x80+0x07,SH%10+0x30);dis(0x80+0x08,.);dis(0x80+0x09,SL/10+0x30);dis(0x80+0x0a,SL%10+0x30);dis(0x80+0x0b,%);dis(0x80+0x0c,R);dis(0x80+0x0d,H);/*温度*/dis(0x80+0X41,T);dis(0x80+0X42,E);dis(0x80+0X43,M);dis(0x80+0X44,:);dis(0x80+0x46,WH/10+0x30);/前为要显示的地址，dis(0x80+0x47,WH%10+0x30);/后为要显示的字符以及该字符对应的字符表的地址dis(0x80+0x48,.);dis(0x80+0x49,WL/10+0x30);dis(0x80+0x4a,WL%10+0x30);dis(0x80+0x4c,0xdf);dis(0x80+0x4d,0x43);vo