220 lines
5.9 KiB
C
220 lines
5.9 KiB
C
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#define ACK 1
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#define noACK 0
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#define measure_temp 0x03 //测量温度命令
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#define measure_humi 0x05 //测量湿度命令
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#define RESET 0x1e //软启动
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#define uchar unsigned char
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#define uint unsigned int
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#define ulong unsigned long
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//------------------------数据结构体定义---------------------------
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typedef union //保存所测得的温度＆湿度值
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{ uint i;
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float f;
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} value;
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typedef struct __WENSHIDU__
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{
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uchar gewei;
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uchar shiwei;
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uchar DateString1[4];
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// uchar DateString2[8];
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}WENSHIDU;
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WENSHIDU S;
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/***************************函数声明*******************************/
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char write_byte(unsigned char value);
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char read_byte(unsigned char ack);
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void transstart(void);
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void connectionreset(void);
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char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode);
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void calc_sth11(float *p_humidity ,float *p_temperature);
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void DateToStr(WENSHIDU *Time,float datax,float datax1);
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void call_sht11(void);
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//--------- write a byte and checks the ack signal-----------------
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char write_byte(uchar value)
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{
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uchar i,error=0;
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for (i=0x80;i>0;i/=2) /*连续向右移动8位*/
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{
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if (i & value)
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HAL_SHT_SDA_SET(); /*把相应的位送数据线*/
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else
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HAL_SHT_SDA_CLR();
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HAL_SHT_SCK_SET(); /*时序脉冲，应严格按着此标准*/
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halMcuWaitUs(1); /*大约 1 us*/
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HAL_SHT_SCK_CLR();
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}
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HAL_SHT_SDA_SET(); /*释放数据线*/
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HAL_SHT_SDA_DIR_IN();
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HAL_SHT_SCK_SET(); /*第9位作为响应位*/
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error=HAL_SHT_SDA_VAL(); /*检测响应情况，如果有响应数据线就会被SHT10拉低*/
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HAL_SHT_SCK_CLR();
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return error; /*返回1表示没响应*/
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}
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//--------- read a byte and checks the ack signal-----------------
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char read_byte(uchar ack)
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{
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uchar i,val=0;
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HAL_SHT_SDA_SET(); /*释放数据线*/
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HAL_SHT_SDA_DIR_IN();
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for (i=0x80;i>0;i/=2) /*连续向右移动8位*/
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{
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HAL_SHT_SCK_SET(); /*clk for SENSI-BUS*/
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if (HAL_SHT_SDA_VAL())
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val=(val | i); /*read bit */
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HAL_SHT_SCK_CLR();
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}
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MCU_IO_OUTPUT(HAL_BOARD_IO_SHT_SDA_PORT, HAL_BOARD_IO_SHT_SDA_PIN,!ack); /*当ack＝1时拉低数据线*/
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HAL_SHT_SCK_SET(); /*clk #9 for ack*/
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halMcuWaitUs(1); /*pulswith approx 1 us */
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HAL_SHT_SCK_CLR();
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HAL_SHT_SDA_SET(); /*释放数据线*/
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return val;
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}
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void transstart(void)
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{
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HAL_SHT_SCK_SET();
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halMcuWaitUs(1);
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HAL_SHT_SDA_CLR();
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halMcuWaitUs(1);
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HAL_SHT_SCK_CLR();
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halMcuWaitUs(2);
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HAL_SHT_SCK_SET();
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halMcuWaitUs(1);
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HAL_SHT_SDA_SET();
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halMcuWaitUs(1);
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HAL_SHT_SCK_CLR();
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halMcuWaitUs(2);
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HAL_SHT_SDA_CLR();
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}
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void connectionreset(void)
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{
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unsigned char i;
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HAL_SHT_SDA_SET();
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HAL_SHT_SCK_CLR(); //Initial state
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for(i=0;i<9;i++) //9 SCK cycles
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{
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HAL_SHT_SCK_SET();
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HAL_SHT_SCK_CLR();
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}
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transstart(); //transmission start
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}
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char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode)
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{
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unsigned error=0;
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uint i;
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connectionreset();
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switch(mode)
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{ //发送寄存器地址给传感器
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case 0 : error+=write_byte(measure_temp); break;
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case 1 : error+=write_byte(measure_humi); break;
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default : break;
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}
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HAL_SHT_SDA_DIR_IN();
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for (i=0;i<35000;i++)
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{
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halMcuWaitUs(1);
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if(HAL_SHT_SDA_VAL()== 0) break;
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} //等待拉低数据线
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if(HAL_SHT_SDA_VAL()) error+=1;
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*(p_value+1) =read_byte(ACK); //读高字节
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*(p_value)=read_byte(ACK); //读低字节
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*p_checksum =read_byte(noACK);
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return error;
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}
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void calc_sth11(float *p_humidity ,float *p_temperature)
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{
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const float C1=-4.0; //for 12 Bit
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const float C2=+0.0405; //for 12 Bit
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const float C3=-0.0000028; //for 12 Bit
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const float T1=+0.01; //for 14 Bit @ 5V
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const float T2=+0.00008; //for 14 Bit @ 5V
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float rh=*p_humidity; //rh: Humidity [Ticks] 12 Bit
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float t=*p_temperature; //*t: Temperature [Ticks] 14 Bit
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float rh_lin; //rh_lin: Humidity linear
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float rh_true; //rh_true: Temperature compensated humidity
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float t_C; //t_C : Temperature [癈]
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t_C=t*0.01 - 40; //calc. temperature from ticks to [癈]
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rh_lin=C3*rh*rh + C2*rh + C1; //calc. humidity from ticks to [%RH]
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rh_true=(t_C-25)*(T1+T2*rh)+rh_lin; //calc. temperature compensated humidity [%RH]
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if(rh_true>100)rh_true=100; //cut if the value is outside of
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if(rh_true<0.1)rh_true=0.1; //the physical possible range
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*p_temperature=t_C; //return temperature [癈]
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*p_humidity=rh_true; //return humidity[%RH]
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}
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void DateToStr(WENSHIDU *Time,float datax,float datax1)
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{
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uint i;
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i=(int)datax;
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Time->DateString1[0] = i;
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i=(int)((datax-i)*10);
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Time->DateString1[1] = i;
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i=(int)datax1;
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Time->DateString1[2] = i;
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i=(int)((datax1-i)*10);
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Time->DateString1[3] = i;
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}
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void call_sht11(void)
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{
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value humi_val,temp_val;
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unsigned char error = 0,checksum;
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error+=s_measure((unsigned char*) &humi_val.i,&checksum,1); //measure humidity
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error+=s_measure((unsigned char*) &temp_val.i,&checksum,0); //measure temperature
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if(error!=0)
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connectionreset(); //如果发生错误，系统复位
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else
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{
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humi_val.f=(float)humi_val.i; //converts integer to float
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temp_val.f=(float)temp_val.i; //converts integer to float
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calc_sth11(&humi_val.f,&temp_val.f); //calculate humidity,temperature
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DateToStr(&S,temp_val.f,humi_val.f);
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}
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}
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