'{$STAMP BS2e}
' Program MAX667x.bse
' Demo of MAXIM thermocouple interface chip.
' thermocouple pins
' +5.0 volts to MAXpin4
' common to MAXpin1
' k thermocouple to (-) red alumel pin 2, and (+) yellow chromel pin 3
' or t thermocouple to (-) red constantan pin 2, and (+) blue copper pin 3
' SPI pins as follows:
thdta	con 8   ' MAXpin7 brown
thcs	con 9	' MAXpin6 white
thclk	con 10  ' MAXpin5 green
   
result	var word
THC	var word	' degrees Celsius (* power of 10)
THCb	var bit
   
initialize:
  outs=0
  dirs=%1111111011111111
  '     fedcba9876543210
   
mainloop:
   
getMAX667x:
  low thcs	' select chip
  shiftin thdta,thclk,msbpre,[result\16]	' get data
  high thcs	' start new data capture
   
  THC=result>>5*/3200	' for MAX6674 0-128 +/- 0.01 degC, up to 127.87
  debug dec THC/100,".",dec2 THC,cr
  pause 250	' conversion time required between readings
goto mainloop
   
' other conversion options
' for MAX6674 results +/- 0.125 up to 65.535 degrees C
' THC=result>>5*/32000
'    debug dec THC/1000,".",dec3 THC,cr
'
' for MAX6675 +/- 0.25 degC, up to 655.25
' THC=result>>3*/6400
'    debug dec THC/100,".",dec2 THC,cr
   
' for MAX6675 +/- 0.1 degC, up to 1023.7
' THC=result>>3*/640
'    debug dec THC/10,".",dec1 THC,cr
   
' 0.1 degree C is probably the limit of meaningful resolution.   