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温湿度传感器SHT11的驱动程序.rar
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- /*******************************************************************
- *【文 件 名】:SHT11.h *
- *【建立日期】:7月5日 *
- *【修改日期】:7月5日 *
- *【文件作用】:温湿度传感器SHT11的驱动程序,提供了外界调用接口函数 *
- *【说 明】: *
- *------------------------------------------------------------------*
- *【作 者】:郭鑫(ben) *
- *【版 权】:国家创新性实验项目,编号GCS07001 *
- *******************************************************************/
- #ifndef _SHT11_08_07_5_
- #define _SHT11 _08_07_5_
- /***************************头文件部分*****************************/
- #include <reg52.h>
- #define ACK 1
- #define noACK 0
- #define measure_temp 0x03 //测量温度命令
- #define measure_humi 0x05 //测量湿度命令
- #define RESET 0x1e //软启动
- #define uchar unsigned char
- #define uint unsigned int
- #define ulong unsigned long
- //-------------------------管脚定义--------------------------------
- sbit DATA=P1^0;
- sbit SCK=P1^1;
- //------------------------数据结构体定义---------------------------
- typedef union //保存所测得的温度&湿度值
- { uint i;
- float f;
- } value;
- typedef struct __WENSHIDU__
- {
- uchar gewei;
- uchar shiwei;
- uchar DateString1[5];
- uchar DateString2[6];
- }WENSHIDU;
- /***************************函数声明*******************************/
- char write_byte(unsigned char value); // write a byte and checks the ack signal
- char read_byte(unsigned char ack); //read a byte and checks the ack signal
- void transstart(void);
- void connectionreset(void);
- char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode);
- void calc_sth11(float *p_humidity ,float *p_temperature);
- void DateToStr(WENSHIDU *Time,float datax,float datax1);
- void call_sht11(void);
- void sht11_window(void); //温湿度界面显示
- //--------- write a byte and checks the ack signal-----------------
- char write_byte(uchar value)
- {
- uchar i,error=0;
- for (i=0x80;i>0;i/=2) /*连续向右移动8位*/
- {
- if (i & value) DATA=1; /*把相应的位送数据线*/
- else DATA=0;
- SCK=1; /*时序脉冲,应严格按着此标准*/
- _nop_();
- _nop_();
- _nop_(); /*大约0.5us*/
- SCK=0;
- }
- DATA=1; /*释放数据线*/
- SCK=1; /*第9位作为响应位*/
- error=DATA; /*检测响应情况,如果有响应数据线就会被SHT10拉低*/
- SCK=0;
- return error; /*返回1表示没响应*/
- }
- //--------- read a byte and checks the ack signal-----------------
- char read_byte(uchar ack)
- {
- uchar i,val=0;
- DATA=1; /*释放数据线*/
- for (i=0x80;i>0;i/=2) /*连续向右移动8位*/
- {
- SCK=1; /*clk for SENSI-BUS*/
- if (DATA) val=(val | i); /*read bit */
- SCK=0;
- }
- DATA=!ack; /*当ack=1时拉低数据线*/
- SCK=1; /*clk #9 for ack*/
- _nop_();_nop_();_nop_(); /*pulswith approx. 5 us */
- SCK=0;
- DATA=1; /*释放数据线*/
- return val;
- }
- /*******************************************************************
- *【函 数 名】:transstart *
- *【修改日期】:2008年7月5日 *
- *【函数作用】:传输控制,发出传输开始命令 *
- *------------------------------------------------------------------*
- *【备 注】: *
- *******************************************************************/
- void transstart(void)
- {
- DATA=1;
- SCK=0; //初始状态
- _nop_();
- SCK=1;
- _nop_();
- DATA=0;
- _nop_();
- SCK=0;
- _nop_();_nop_();_nop_();
- SCK=1;
- _nop_();
- DATA=1;
- _nop_();
- SCK=0;
- }
- /*******************************************************************
- *【函 数 名】:connectionreset *
- *【修改日期】:2008年7月5日 *
- *【函数作用】:复位:当DATA线处于高低平时,触发SCK9次以上(含9次) *
- * 此后应接发一个"传输开始"命令 *
- *------------------------------------------------------------------*
- *【备 注】: *
- *******************************************************************/
- void connectionreset(void)
- {
- unsigned char i;
- DATA=1; SCK=0; //Initial state
- for(i=0;i<9;i++) //9 SCK cycles
- {
- SCK=1;
- SCK=0;
- }
- transstart(); //transmission start
- }
- //-------makes a measurement (humidity/temperature) with checksum-----
- char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode)
- {
- unsigned error=0;
- uint i;
- transstart(); //transmission start
- switch(mode){ //send command to sensor*/
- case 0 : error+=write_byte(measure_temp); break;
- case 1 : error+=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) =read_byte(ACK); //read the first byte (MSB)
- *(p_value+1)=read_byte(ACK); //read the second byte (LSB)
- *p_checksum =read_byte(noACK); //read checksum
- return error;
- }
- //---------------温湿度值标度变换及温度补偿-------
- void calc_sth11(float *p_humidity ,float *p_temperature)
- {
- 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 [癈]
- t_C=t*0.01 - 40; //calc. temperature from ticks to [癈]
- 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 [癈]
- *p_humidity=rh_true; //return humidity[%RH]
- }
- /*******************************************************************
- *【函 数 名】:DateToStr *
- *【修改日期】:2008年7月5日 *
- *【函数作用】:数值转换,供显示使用 *
- *------------------------------------------------------------------*
- *【备 注】: *
- *******************************************************************/
- void DateToStr(WENSHIDU *Time,float datax,float datax1)
- {
- uint i;
- i=(int)datax;
- Time->shiwei=i/10;
- Time->gewei =i%10;
- Time->DateString1[0] = Time->shiwei + '0';
- Time->DateString1[1] = Time->gewei + '0';
- i=(int)((datax-i)*10);
- Time->DateString1[2] ='.';
- Time->DateString1[3] = i + '0';
- Time->DateString1[4] = '\0';
- i=(int)datax1;
- Time->shiwei=i/10;
- Time->gewei =i%10;
- Time->DateString2[0] = Time->shiwei + '0';
- Time->DateString2[1] = Time->gewei + '0';
- i=(int)((datax1-i)*10);
- Time->DateString2[2] ='.';
- Time->DateString2[3] = i + '0';
- Time->DateString2[4] = '%';
- Time->DateString2[5] = '\0';
- }
- /*******************************************************************
- *【函 数 名】:call_sht11 *
- *【修改日期】:2008年7月5日 *
- *【函数作用】:sht11驱动调用,调用即可完成一次测量 *
- *------------------------------------------------------------------*
- *【备 注】: *
- *******************************************************************/
- void call_sht11(void)
- {
- WENSHIDU S;
- value humi_val,temp_val;
- unsigned char error,checksum;
- unsigned int i;
- error=0;
- error+=s_measure((unsigned char*) &humi_val.i,&checksum,1); /*measure humidity*/
- error+=s_measure((unsigned char*) &temp_val.i,&checksum,0); /*measure temperature*/
- if(error!=0)
- 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*/
- DateToStr(&S,temp_val.f,humi_val.f);
- lcd_setposition(2,5);
- lcd_str_w(S.DateString1);
- lcd_setposition(3,5);
- lcd_str_w(S.DateString2);
- }
- //----------wait approx. 0.8s to avoid heating up SHT10------------------------------ */
- for (i=0;i<10000;i++); //(be sure that the compiler doesn't eliminate this line!)
- //----------------------------------------------------------------------------------- */
- }
- //--------------------温湿度界面显示------------------------
- void sht11_window(void)
- {
- lcd_cmd_w(0x01);
- lcd_setposition(1,1);
- lcd_str_w("温湿测量系统");
- lcd_setposition(2,0);
- lcd_str_w("当前温度:");
- lcd_setposition(3,0);
- lcd_str_w("当前湿度:");
- }
- #endif
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