Jason Engelman / Mbed 2 deprecated max6675

Dependencies:   mbed

max6675.cpp@0:b49d36e03092, 2010-05-15 (annotated)

Committer:
tecnosys
Date:
Sat May 15 06:26:05 2010 +0000
Revision:
0:b49d36e03092
Child:
2:661ac326e3b3

        

        
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#include <mbed.h>





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#include "max6675.h"





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max6675::max6675(SPI& _spi, PinName _ncs) : spi(_spi), ncs(_ncs) {





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}





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float max6675::read_temp() {





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    short value = 0;





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    float temp = 0;





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    uint8_t highByte=0;





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    uint8_t lowByte=0;





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    select();





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    wait(.25); //This delay is needed else it does'nt seem to update the temp





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    highByte = spi.write(0);





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    lowByte = spi.write(0);





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    deselect();





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    if (lowByte & (1<<2)) {





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        printf("No Probe");





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    } else {





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        value = (highByte << 5 | lowByte>>3);





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    }





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    temp = (value*0.25); // Multiply the value by 0.25 to get temp in ˚C or





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                         //  * (9.0/5.0)) + 32.0;   // Convert value to ˚F (ensure proper floats!)





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return temp;





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}





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void max6675::select() {





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    ncs = 0;





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}





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void max6675::deselect() {





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    ncs = 1;





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}