Max31855 Thermocouple Temperature Reading

I was looking hard to find a picbasic code for the new MAX31855 from Maxim but I could't find anywhere.
This is a nice chip to read temperature from -210 up to 1300 C for many types of thermocouples with internal ColdJuction and faults report!!.
Here is datasheet for details : http://datasheets.maximintegrated.co...s/MAX31855.pdf

Thermocouples are using for high temperatures, so I am not interesting for negative sign !!!
I send data to PC using Hyperterminal at 9600 bauds.
Brown out detect is disable So I can use 3.3 Volts supply on my pic16f877A
I hope this code is usefull for you as is for me!

Code:

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define OSC 20
@ DEVICE PIC16F877A,HS_OSC,WDT_ON,MCLR_OFF,BOD_Off,LVP_OFF,PROTECT_OFF
include "modedefs.bas"


'----- Data Output To Pc Without MAX232 at 9600bauds reverse ----

DataTx var portc.6  'TX serial data to PC
BaudTx con 16468    '9600 bauds reverse



'Alias pins - MAX31855 temp sensor
      MXSCLK      var    PORTD.0  'MAX31855 Clock
      MXCS        var    PORTD.1  'MAX31855 Chip Select
      MXSO        Var    PORTD.3  'MAX31855 Serial Data 
      '--Variables-----------------------
      TCtemp      var    word    'raw data from MAX31855
      tempC      var    word    'temperature in degrees C
      tempF      var    word    'temp C converted to degrees F 
      CJtemp      var    word    'raw data from MAX31855
      tempcjC      var    word    'temperature ColdJuction in degrees C
      tempcjF      var    word    'ColdJuction C converted to degrees F 
   


  '-----------Read and display temperature from MAX31855-----------
 
      main:
 
      'Read Temp of Thermocouple
     
      LOW MXCS                            'chip select low   
      shiftin MXSO, MXSCLK, 0, [TCtemp\16] 'shift in the data   
      HIGH MXCS                          'chip select high   
      tempC =  TCtemp >> 4              'side shift to ditch the stuff to the right of the decimal point and just show whole degrees)     
      tempF = ((tempC * 18)/10) + 32      'convert C to F           
   
    '--------- Send Temp To PC ------------------
      if TempC.bit11 = 0 then        'Positive Sign of Temperature
      SEROUT2 DataTx,BaudTx, ["Theromocouple ",dec tempc ," degrees C  ",dec tempF," degrees F  " ,10,13 ] 'display the data on PC   
      PAUSE 1000
      else
        SEROUT2 DataTx,BaudTx, ["OUT of Range ",10,13 ]
        pause 1000
            endif
     
      'Read Temp of ColdJuction
      LOW MXCS                            'chip select low   
      shiftin MXSO, MXSCLK, 0, [CJtemp\32] 'shift in the data   
      HIGH MXCS                          'chip select high   
      tempcjC  =  CJtemp>> 8                'side shift to ditch the stuff to the right of the decimal point and just show whole degrees)     
      tempcjF  = ((tempcjC * 18)/10) + 32      'convert C to F           
   
     
     
      '--------- Send Cj Temp To PC ------------------
      SEROUT2 DataTx,BaudTx, ["ColdJuction ",dec tempcjc ," degrees C  ",dec tempcjF," degrees F  " ,10,13 ] 'display the data on PC   
      pause 1000
   
   
    'Check Thermocouple Status
      IF CJtemp.bit0=1  THEN
      SEROUT2 DataTx,BaudTx, [" NO CONNECTION  " ,10,13 ] 'display the data on PC   
          pause 1000 
      ENDIF
 
    IF CJtemp.bit1=1  THEN
      SEROUT2 DataTx,BaudTx, [" SHORT to GND " ,10,13 ] 'display the data on PC
          pause 1000 
      ENDIF

        IF CJtemp.bit2=1  THEN
      SEROUT2 DataTx,BaudTx, [" SHORT to VCC  " ,10,13 ] 'display the data on PC 
    PAUSE 1000
      ENDIF
     
      goto main   
      end

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Thank you! :)

Thank you, I modify your code to work with PIC16F690 and to display temperature on serial 20x4 LCD and it works great.

I have also tried to modify this code for LCD, but I'm getting very low readings in C. and also, they change strangely - when I heat thermocouple, they start to increase, than at some point (always different), will decrease by 5-10C and then again increase.

Thanks Lefteris - this was very helpful. Not clear why you shift the data right by 4 bits, but it works great. Thanks for posting this! :)

Code:

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@ __config _HS_OSC & _WDT_ON & _PWRTE_ON &_BODEN_OFF & _LVP_OFF & _CPD_OFF

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Appears orig. config was for PB compiler AND NOT for 16F877a as stated as there is NO MCLR or PROTECT