Introduction: Arduino and Thermocouple K MAX6675

Picture of Arduino and Thermocouple K MAX6675

Connecting the thermocouple K MAX6675 to an Arduino Mega.

For this example I used a cheap arduino mega 2560 from SainSmart.

The thermocouple K MAX6675 is a convert that allows temperature reading from 0ºC to 1024ºC. You can learn more about it by read the datasheet here.

Step 1: Material

Picture of Material

1 - Arduino

2 - ThermoCouple K MAX6675

3 - USB Cable

Step 2: Wiring the Material

Picture of Wiring the Material

So now we connect the thermocouple to the pin 45 to 53 (in the arduino the pins goes in pairs)

Step 3: Coding Like a Pro...

Picture of Coding Like a Pro...

First of all I need to find a Library who help us to communicate with the sensor. After browsing the web for a couple of hours and testing the libraries, I enjoyed that one, ThermoCoupleK from LadyAda who I believe don't mind if we use it.

After looking at some examples I ended with this code (that is close to the one I found).

Step 4: Conclusion

As you can see it's quite easy to create a K-type temperature reader. Now it's up to you to found an application to this instructable.

That's all folks


ElliotS8 (author)2017-10-26


I am trying to use a switch case function and while function based on the temperature read of the thermocouple. However, when I try to have the arduino read the temp to test the while statement nothing happens. How can I have the arduino read the temp for the while statement?

Amir HoseinS (author)2017-10-19


can I use max 31855k ?

my probe is pt100

I want to use this project for artisan software (coffee roaster)

please help me


I never tested that one but you can try it. For that you should change the library for this one ( the one I use is fot the MAX6675.

Good Luck

WeiJ6 (author)2016-11-07

Hi,dude. Where can I get the coding for 2 points calibration of thermocouple ? Thank you in advance

KomailM (author)2016-03-25

hi . how can i wire max6675 to ramps ? and what config should i do in repetier firmware ?

ThomasK19 (author)KomailM2016-10-03

I'm using Marlin, so can't tell about repetier. But search your sketches for 6675 and you will eventually find the according #defines.

ncaulford (author)2016-04-06

I'm a supreme noob. Should I have another file that the code is looking for?

I'm getting an error :(

Arduino: 1.6.7 (Mac OS X), Board: "Arduino/Genuino Uno"

/xxx/xxx/Downloads/ThermoCoupleK/ThermoCoupleK.ino:1:21: fatal error: max6675.h: No such file or directory

#include <max6675.h>


compilation terminated.

exit status 1

Error compiling.

ThomasK19 (author)ncaulford2016-10-03

Put the max6675.cpp and .h in the same folder as where your .ino is located. Open the .ino once again. You should now see two more tabs in the Arduino IDE for the both max6676 files.

gotmlenjoy (author)2016-10-03

how if use 5 thermocouple in one arduino it si possible or not ? :)

ThomasK19 (author)gotmlenjoy2016-10-03

Just use the CS pin to select the individual couple. Only the one that has CS set high will response on the data line.

CalvinM1 (author)2016-06-07

Which pins can I use in an arduino uno?

Look a potato made it! (author)CalvinM12016-06-08

Hello CalvinM1,

you can use any digital pin, you just have to configure them in the code. Here:

CesarO6 (author)2016-02-05

does the max6675 IC works with any brand of k-type thermocouple? i am using this one

but the measurements on the serial terminal are very wrong. The impedance of my thermocouple is less than 2 ohm. Can you explain me please how to use correctly my thermocouple with the IC ?

Look a potato (author)CesarO62016-02-05


I'm not really sure how it will work cause the TC-K range is between 0-800ºC and the MAX6675 is between 0-1023.75ºC. You must need to adjust the limits to match the same values.

But as I said, I not sure it will work, if someone can help here it will be great.

PaulCo (author)2016-01-22

fixed problem..

both controllers from ebay are faulty,

made my own and works great, thank you for your splendid tutorial..

Look a potato (author)PaulCo2016-01-22

Happy to ear that.

Thanks for the support and good luck with your development.

PaulCo (author)2016-01-21

the model is MAX6675
pinout is : gnd, vcc, sck, cs, so

PaulC175 (author)2016-01-21

hi my pinout is :




I tied :




but no joy, would you know my pinout to yours

Look a potato (author)PaulC1752016-01-21

Hey there,

is your thermocouple a MAX6675? Check the annotation on the thermocouple board and let me know your model to try to help you.


kike1925 (author)2015-12-06

excelente aportacion

Look a potato (author)kike19252015-12-09

thank you

dergott (author)2015-01-06

Very cool !

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