SHT11驱动程序.doc

SHT11.h#ifndef _SHT11_h_#define _SHT11_h_#define uchar unsigned char#define uint unsigned int#define NOP() _nop_()#define TEMP 0#define HUMI 1sbit DQ=P27; /端口定义sbit SCK=P26;typedef structfloat temperature;float humidity;float crc_temp;float crc_humi;uchar num_temp5;uchar num_humi5;SHT_dat;/*=启动函数=*/void init_SHT()DQ=1;SCK=0;NOP();SCK=1;NOP();DQ=0;NOP();SCK=0;NOP();NOP();NOP();SCK=1;NOP();DQ=1;NOP();SCK=0;/*=字节传送函数=*/uchar write_byte(uchar value)uchar i,error=0;for(i=0x80;i0;i/=2) /高位先传送if(i & value)DQ=1; /循环相与，结果即为要发送的位else DQ=0;SCK=1;NOP();NOP();NOP();SCK=0;DQ=1; /释放总线SCK=1;if(DQ=1) error=1; /检查应答，确认通讯正常SCK=0;return error; /error1，通讯有误/*=读数据函数=*/uchar read_byte(uchar dat)uchar i,val=0;DQ=1;for(i=0x80;i0;i/=2)SCK=1;if(DQ) val=(val | i);SCK=0;DQ=dat;SCK=1;NOP();NOP();NOP();SCK=0;DQ=1;return val;/*=复位函数=*/void reset_SHT()uchar i;DQ=1;SCK=0;for(i=0;i9;i+) /DATA保持高电平，SCK时钟出发9次复位SCK=1;NOP();SCK=0;init_SHT();/*=发送指令到SHT11执行温度和湿度的测量转换=*/convert_SHT(SHT_dat *s,uchar mode)uchar i,ack=0;uchar valueM,valueL,checksum;float com;doreset_SHT();switch(mode)case TEMP: ack=write_byte(0x03);break;case HUMI: ack=write_byte(0x05);break;default: break;while(ack=1);for(i=0;itemperature=com;s-crc_temp=(float)checksum;if(mode=HUMI)s-humidity=com;s-crc_humi=(float)checksum;/*=温度和湿度补偿及输出温度值和相对湿度值=*/void caculation_SHT(SHT_dat *s)const float c1=-4.0;const float c2=+0.0405;const float c3=-0.0000028; /以上为12位湿度修正公示取值const float t1=+0.01;const float t2=+0.00008; /以上为14位温度修正公示取值float t=s-temperature;float rh=s-humidity;float rh_lin;float rh_ture;float t_c;t_c=t * 0.01 - 40; /温度的补偿rh_lin=c3*rh*rh + c2*rh + c1; /相对湿度非线性补偿rh_ture=( t_c - 25 ) * ( t1 + t2*rh ) + rh_lin; /相对湿度对于温度依赖性补偿if( rh_ture 100 ) rh_ture=100; /相对湿度最大值修正if( rh_ture 0.1 ) rh_ture=0.1; /相对湿度最小值修正if(t_ctemperature=t_c; /保存温度补偿后的结果s-humidity=rh_ture; /保存相对湿度补偿后的结果/*=计算绝对湿度值=float calc_dewpoint(float h,float t)float logEx,dew_point;logEx=0.66077+7.5*t/(237.3+t)+(log10(h)-2);dew_point = (logEx - 0.66077)*237.3/(0.66077+7.5-logEx);return dew_point;/*=浮点数数据处理=*/void float_convert(SHT_dat *s)float com;uint dat;com=s-temperature;com*=100;dat=(uint)com;s-num_temp0=dat/1000+0x30; /十位s-num_temp1=dat%1000/100+0x30; /个位s-num_temp2=0x2e;s-num_temp3=dat%100/10+0x30; /小数点第一位s-num_temp4=dat%10+0x30; /小数点第二位com=s-humidity;com*=100;dat=(uint)com;s-num_humi0=dat/1000+0x30; /十位s-n