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/////////////////////////////////////////////////////////////////////////////// |
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/////////////////////////////////////////////////////////////////////////////// |
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//#define sht_data_pin PIN_D0 |
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//#define sht_data_pin PIN_D0 |
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//#define sht_clk_pin PIN_D1 |
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//#define sht_clk_pin PIN_D1 |
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#include <math.h> |
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//#include <math.h> |
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#define noACK 0 |
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#define noACK 0 |
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#define ACK 1 |
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#define ACK 1 |
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//adr command r/w |
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//adr command r/w |
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return error; //error>=1 in case of no response form the sensor |
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return error; //error>=1 in case of no response form the sensor |
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} |
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} |
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//***** Function to measure SHT75 temperature ***** |
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//***** Function to measure SHT75 temperature ***** |
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int16 sht_measuretemp (void) |
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int16 sht_measuretemp () |
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{ |
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{ |
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int1 ack; |
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int1 ack; |
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int16 iobyte; |
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int16 iobyte; |
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sht_comstart(); //alert SHT75 |
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sht_comstart(); //alert SHT75 |
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} |
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} |
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//***** Function to measure SHT75 RH ***** |
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//***** Function to measure SHT75 RH ***** |
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int16 sht_measurehumid (void) |
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int16 sht_measurehumid () |
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{ |
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{ |
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int1 ack; |
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int1 ack; |
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int16 iobyte; |
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int16 iobyte; |
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sht_comstart(); //alert SHT75 |
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sht_comstart(); //alert SHT75 |
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void calculate_data (int16 temp, int16 humid, float & tc, float & rhlin, float & rhtrue) |
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void calculate_data (int16 temp, int16 humid, float & tc, float & rhlin, float & rhtrue) |
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{ |
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{ |
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const float C1=-2.0468; // for 12 Bit RH |
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const float C1=-2.0468; // for 12 Bit RH |
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const float C2=+0.0367; // for 12 Bit RH |
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const float C2=+0.0367; // for 12 Bit RH |
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const float C3=-0.0000015955; // for 12 Bit RH |
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const float C3=-0.0000015955; // for 12 Bit RH |
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const float T1=+0.01; // for 12 Bit RH |
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// const float T1=+0.01; // for 12 Bit RH |
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const float T2=+0.00008; // for 12 Bit RH |
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// const float T2=+0.00008; // for 12 Bit RH |
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float rh; |
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float rh; |
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//calculate temperature reading |
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//calculate temperature reading |
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tc = ((float) temp * 0.01) - 40.0; |
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tc = ((float) temp * 0.01) - 40.0; |
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sht_comreset(); //reset SHT75 |
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sht_comreset(); //reset SHT75 |
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delay_ms(20); //delay for power-up |
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delay_ms(20); //delay for power-up |
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} |
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} |
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//-------------------------------------------------------------------- |
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//-------------------------------------------------------------------- |
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float calc_dewpoint(float h,float t) |
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//float calc_dewpoint(float h,float t) |
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//-------------------------------------------------------------------- |
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//-------------------------------------------------------------------- |
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// calculates dew point |
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// calculates dew point |
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// input: humidity [%RH], temperature [K] |
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// input: humidity [%RH], temperature [K] |
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// output: dew point [K] |
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// output: dew point [K] |
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{ float k,dew_point ; |
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//{ float k,dew_point ; |
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// |
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k = (log10(h)-2)/0.4343 + (17.62*t)/(243.12+t); |
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// k = (log10(h)-2)/0.4343 + (17.62*t)/(243.12+t); |
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dew_point = 243.12*k/(17.62-k); |
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// dew_point = 243.12*k/(17.62-k); |
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return dew_point; |
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// return dew_point; |
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} |
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//} |
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