Having trouble with SERIN command and MAX6675

[mackrackit]

Unless you are trying to get the fractional part of the reading 10 bits is all you need.

[flotulopex]

Unless you are trying to get the fractional part of the reading 10 bits is all you need.

I don't get it, Dave...

[richard]

why do I have to shift by "2" instead of what has been said above (shift by 3) or even shift by 1 since bit 14 is the second bit to start with?

the data can be read in msb first by shiftin but it is then translated to a normal binary representation so bit 14 is read as bit 14.

shifting by 2 is incorrect , as dave indicated
Temp = RawTemp >> 5
will get the high 10 bits of the 12bit reading ,resulting in the integer component of the reading

or

Temp = RawTemp >> 3
int_part=temp/4
fract_part=(temp//4)*25

lcdout $FE, $C0,"Tmp ", #int_part,".",dec2 fract_part," C"

[flotulopex]

This is confusing to me.

My code gives me almost exactly what my home thermometer shows:


This code

Temp = RawTemp >> 3
int_part=temp/4
fract_part=(temp//4)*25
lcdout $FE, $C0,"Tmp ", #int_part,".",dec2 fract_part," C"

display this:

Where is the truth?

[richard]

for a start your temp var is a declared as byte , how can 12 bit reading fit in that ?

[flotulopex]

I corrected my code just after I sent it - couldn't edit the post anymore, should have mentionned it, sorry

[flotulopex]

Anyway, I understand the calculation to get the temperature value BUT why do I have around 5°C diffrence between the thermocouple and my home thermometer?

Must a thermocouple be kind of "adjusted" (correct the result in the code) or something like that?