Measuring Temperature using Thermocouples

[klakma]

Sorry its literally the first circuit I have ever drawn in my life, I'll try to find some software tomorrow which has something resembling the max31855 and a 2 channel relay and I'll draw something digitally

@rainyshadow

@klakma

according to the ebay seller (in the article I posted earlier), it takes everything from 3-5V. So I should be fine using either 3.3 or 5V

Hmm, the only link i see in your initial post is the one within the code - https://www.adafruit.com/products/269
That module has a lot more (visible) parts than the one in your last picture.

Compare the two:

I found this, is that the same you have?
Either the pictures or the description appear to be wrong - there is no voltage regulator, no level shifting circuitry, only the chip and a bypass capacitor.

Wow yeah I didnt notice that they look different. In retrospect it was luck but I have the one which I posted, so its the "simple" version with no voltage regulator. So I guess atleast some part definetely comes from the wrong voltage, altough the Issue still persists even if I power both with 3.3V

@JohnRob

@klakma

and according to the ebay seller (in the article I posted earlier), it takes everything from 3-5V. So I should be fine using either 3.3 or 5V.

The ebay seller has no clue. This board has only the Max31855, no other active parts. It is a 3.3V input board because it is a 3.3V IC. See post #6 for what is a superior board (in my view). Also note the I/O lines are still 3.3V. You might get away with a resistor in the CS\ and CLK lines.

Wait, so you think the Adafruit Board is superior or the Maxim one ? I have thought about replacing my Boards with the Maxim ones but they are pretty expensive (~20€ per Board)

@JohnRob

Have you run with two thermocouple boards? If so you have maybe the OP could glean some information from how your code setup the two boards and what pins you used.

As for my opinion of the Adafruit driver(s). I never suggested they were not usable, I just found for me the few lines of code I needed to read the sensor was much smaller than the Adafruit library. However I will admit I don't have any info of the compiled size of the two approaches.

Im sorry I am unsure about your first question.