~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 功能说明:SHT10与上位机（串口调试助手）的温湿度显示 微处理器:STC89C52 编译环境:Keil uVision V4 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ;*************************************************************/ #include <reg52.h> //Microcontroller specific library, e.g. port definitions #include <intrins.h> //Keil library (is used for _nop()_ operation) #include <math.h> //Keil library #include <stdio.h> //Keil library /*************定义接口****************** P2.6------SCK (SHT10) P2.7------DATA (SHT10) *****************************************/ sbit SCK = P2^6; //定义通讯时钟端口 sbit DATA = P2^7; //定义通讯数据端口 typedef union { unsigned int i; //定义了两个共用体 float f; } value; enum {TEMP,HUMI}; //枚举测量温度或湿度 #define noACK 0 //用于判断是否结束通讯 #define ACK 1 //结束数据传输 //adr command r/w #define STATUS_REG_W 0x06 //000 0011 0 #define STATUS_REG_R 0x07 //000 0011 1 #define MEASURE_TEMP 0x03 //000 0001 1 #define MEASURE_HUMI 0x05 //000 0010 1 #define RESET 0x1e //000 1111 0 /****************定义函数****************/ void s_transstart(void); //启动传输函数 void s_connectionreset(void); //连接复位函数 char s_write_byte(unsigned char value);//SHT10写函数 char s_read_byte(unsigned char ack); //SHT10读函数 char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode);//测量温湿度函数 void calc_sht10(float *p_humidity ,float *p_temperature);//温湿度补偿 float calc_dewpoint(float h,float t); //计算露点 //char s_softreset(void); //char s_read_statusreg(unsigned char *p_value, unsigned char *p_checksum); //char s_write_statusreg(unsigned char *p_value); /*-------------------------------------- ;模块名称:s_write_byte(); ;功 能:SHT10写函数 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ char s_write_byte(unsigned char value) // writes a byte on the Sensibus and checks the acknowledge { unsigned char i,error=0; for (i=0x80;i>0;i/=2) //shift bit for masking { if (i & value) DATA=1; //masking value with i , write to SENSI-BUS else DATA=0; SCK=1; //clk for SENSI-BUS _nop_();_nop_();_nop_(); //pulswith approx. 5 us SCK=0; } DATA=1; //release DATA-line SCK=1; //clk #9 for ack error=DATA; //check ack (DATA will be pulled down by SHT11) SCK=0; return error; //error=1 in case of no acknowledge } /*-------------------------------------- ;模块名称:s_read_byte(); ;功 能:SHT10读函数 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ char s_read_byte(unsigned char ack) // reads a byte form the Sensibus and gives an acknowledge in case of "ack=1" { unsigned char i,val=0; DATA=1; //release DATA-line for (i=0x80;i>0;i/=2) //shift bit for masking { SCK=1; //clk for SENSI-BUS if (DATA) val=(val | i); //read bit SCK=0; } DATA=!ack; //in case of "ack==1" pull down DATA-Line SCK=1; //clk #9 for ack _nop_();_nop_();_nop_(); //pulswith approx. 5 us SCK=0; DATA=1; //release DATA-line return val; } /*-------------------------------------- ;模块名称:s_transstart(); ;功 能:启动传输函数 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ void s_transstart(void) // generates a transmission start // _____ ________ // DATA: |_______| // ___ ___ // SCK : ___| |___| |______ { DATA=1; SCK=0; //Initial state _nop_(); SCK=1; _nop_(); DATA=0; _nop_(); SCK=0; _nop_();_nop_();_nop_(); SCK=1; _nop_(); DATA=1; _nop_(); SCK=0; } /*-------------------------------------- ;模块名称:s_connectionreset(); ;功 能:连接复位函数 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ void s_connectionreset(void) // communication reset: DATA-line=1 and at least 9 SCK cycles followed by transstart // _____________________________________________________ ________ // DATA: |_______| // _ _ _ _ _ _ _ _ _ ___ ___ // SCK : __| |__| |__| |__| |__| |__| |__| |__| |__| |______| |___| |______ { unsigned char i; DATA=1; SCK=0; //Initial state for(i=0;i<9;i++) //9 SCK cycles { SCK=1; SCK=0; } s_transstart(); //transmission start } /* //---------------------------------------------------------------------------------- char s_softreset(void) //---------------------------------------------------------------------------------- // resets the sensor by a softreset { unsigned char error=0; s_connectionreset(); //reset communication error+=s_write_byte(RESET); //send RESET-command to sensor return error; //error=1 in case of no response form the sensor } //---------------------------------------------------------------------------------- char s_read_statusreg(unsigned char *p_value, unsigned char *p_checksum) //---------------------------------------------------------------------------------- // reads the status register with checksum (8-bit) { unsigned char error=0; s_transstart(); //transmission start error=s_write_byte(STATUS_REG_R); //send command to sensor *p_value=s_read_byte(ACK); //read status register (8-bit) *p_checksum=s_read_byte(noACK); //read checksum (8-bit) return error; //error=1 in case of no response form the sensor } //---------------------------------------------------------------------------------- char s_write_statusreg(unsigned char *p_value) //---------------------------------------------------------------------------------- // writes the status register with checksum (8-bit) { unsigned char error=0; s_transstart(); //transmission start error+=s_write_byte(STATUS_REG_W);//send command to sensor error+=s_write_byte(*p_value); //send value of status register return error; //error>=1 in case of no response form the sensor } */ /*-------------------------------------- ;模块名称:s_measure(); ;功 能:测量温湿度函数 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode) // makes a measurement (humidity/temperature) with checksum { unsigned error=0; unsigned int i; s_transstart(); //transmission start switch(mode){ //send command to sensor case TEMP : error+=s_write_byte(MEASURE_TEMP); break; case HUMI : error+=s_write_byte(MEASURE_HUMI); break; default : break; } for (i=0;i<65535;i++) if(DATA==0) break; //wait until sensor has finished the measurement if(DATA) error+=1; // or timeout (~2 sec.) is reached * (p_value)=s_read_byte(ACK); //read the first byte (MSB) *(p_value+1) =s_read_byte(ACK); //read the second byte (LSB) *p_checksum =s_read_byte(noACK); //read checksum return error; } /*-------------------------------------- ;模块名称:init_uart(); ;功 能:串口初始化 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ void init_uart() //9600 bps @ 11.059 MHz {SCON = 0x52; TMOD = 0x20; TCON = 0x69; TH1 = 0xfd; } /*-------------------------------------- ;模块名称:calc_sht10(); ;功 能:温湿度补偿函数 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ void calc_sth11(float *p_humidity ,float *p_temperature) // calculates temperature [℃] and humidity [%RH] // input : humi [Ticks] (12 bit) // temp [Ticks] (14 bit) // output: humi [%RH] // temp [℃] { const float C1=-4.0; // for 12 Bit const float C2=+0.0405; // for 12 Bit const float C3=-0.0000028; // for 12 Bit const float T1=+0.01; // for 14 Bit @ 5V const float T2=+0.00008; // for 14 Bit @ 5V float rh=*p_humidity; // rh: Humidity [Ticks] 12 Bit float t=*p_temperature; // t: Temperature [Ticks] 14 Bit float rh_lin; // rh_lin: Humidity linear float rh_true; // rh_true: Temperature compensated humidity float t_C; // t_C : Temperature [℃] t_C=t*0.01 - 40; //calc. temperature from ticks to [℃] rh_lin=C3*rh*rh + C2*rh + C1; //calc. humidity from ticks to [%RH] rh_true=(t_C-25)*(T1+T2*rh)+rh_lin; //calc. temperature compensated humidity [%RH] if(rh_true>100)rh_true=100; //cut if the value is outside of if(rh_true<0.1)rh_true=0.1; //the physical possible range *p_temperature=t_C; //return temperature [℃] *p_humidity=rh_true; //return humidity[%RH] } /*-------------------------------------- ;模块名称:calc_dewpoint(); ;功 能:露点，空气湿度达到饱和时的温度 ;占用资源:-- ;参数说明:-- ;创建日期:2012.04.10 ;版 本:FV1.0(函数版本Function Version) ;修改日期:-- ;修改说明:-- ;-------------------------------------*/ float calc_dewpoint(float h,float t) // calculates dew point // input: humidity [%RH], temperature [℃] // output: dew point [℃] { 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; } /*****************主函数*********************/ //---------------------------------------------------------------------------------- void main() //---------------------------------------------------------------------------------- // sample program that shows how to use SHT11 functions // 1. connection reset // 2. measure humidity [ticks](12 bit) and temperature [ticks](14 bit) // 3. calculate humidity [%RH] and temperature [℃] // 4. calculate dew point [℃] // 5. print temperature, humidity, dew point { value humi_val,temp_val; float dew_point; unsigned char error,checksum; unsigned int i; init_uart(); //串口初始化 s_connectionreset(); while(1) { error=0; error+=s_measure((unsigned char*) &humi_val.i,&checksum,HUMI); //measure humidity error+=s_measure((unsigned char*) &temp_val.i,&checksum,TEMP); //measure temperature if(error!=0) s_connectionreset(); //in case of an error: connection reset else { humi_val.f=(float)humi_val.i; //converts integer to float temp_val.f=(float)temp_val.i; //converts integer to float calc_sth11(&humi_val.f,&temp_val.f); //calculate humidity, temperature dew_point=calc_dewpoint(humi_val.f,temp_val.f); //calculate dew point printf("Temp:%5.1f℃ Humi:%5.1f%% Dew point:%5.1f℃\n",temp_val.f,humi_val.f,dew_point); } //----------wait approx. 0.8s to avoid heating up SHTxx------------------------------ for (i=0;i<40000;i++); //(be sure that the compiler doesn't eliminate this line!) //----------------------------------------------------------------------------------- } }