Having trouble with SERIN command and MAX6675

[flotulopex]

Thanks Richard,

With your calculation example you gave me above, I could understand how to read my result.

Do you know if thermocouples are "qualified" according to their precision?

PS: yup, mine has made the travel from China

[richard]

Do you know if thermocouples are "qualified" according to their precision?

not cheapies on ebay .

a more likely source of some probes with actual specs would be rs components ,farnel/element14 ,digikey or similar
but they will cost more.

I have never had the need for real absolute accuracy and just add or subtract a suitable offset to compensate for error,
so far it works acceptably for my 3d printer [precision being more important]

[mackrackit]

And I will add... Take extra care with your cold junctions. The 6675 does a good job compensating if the junction is close and in the same environment as it is. As do not have the cold junction on the outside of an enclosure and the 6675 on the inside. And noise that can be picked up from breadboard connections can be trouble.

[flotulopex]

...As do not have the cold junction on the outside of an enclosure and the 6675 on the inside.

How do you mean this?

[mackrackit]

The MAX6675 has cold junction compensation built in, but only works if the cold junction is close to the MAX6675.
This article explains cold junction compensation in detail. https://www.maximintegrated.com/en/a...ex.mvp/id/4026

[flotulopex]

Nice and very interresting.

Thanks a lot