8 typ-K thermocouple throgh Max31855 module to Arduino Mega 2560

Hello all , i am totally new in all this . i have no background in electrical or coding . i am attaching my circuit which i made in fritzing . can someone tell me the my connection are right or wrong. if i will do it in real then every thing will be ok?.

i am planning to connect 8 type k thermocouples through 8 max31855 module to the arduino mega 2560. i am attaching here picture .

here is my thermocouple details.

here is my max31855 module details.
MAX31855 Module + K-Type Thermocouple Thermocouple Sensor Temperature ā€‘200ā„ƒ~1350ā„ƒ Thermocouple Thermometer and Probes

Your best bet is to upload the Fritzing Sharable Sketch (.fzz) file so that we can help youā€¦

Final Thermocouple.fzz (61.0 KB)

Thanks!
Iā€™m halfway done fixing up the schematic. Itā€™s getting ;ate at my side, but Iā€™ll continue tomorrow

1 Like

okay , thanks a lot . it will be a very helpful for me ā€¦

Hello
is there any update for me ?

thanks a lot

Sorry for the late replyšŸ˜„

Lately I realised a larger problem ā€“ the thermocouple operates at 3.3V logic levels, while the arduino mega 2560 operates at 5V logic levels!

Iā€™ve never dealt with 3.3V logic levels before, (or rather very rarely) so I have no idea how to connect it to an arduino.

If anyone knows, please post! Otherwise @js13ropa you should ask the folks at adafruit for help hereā€¦
https://forums.adafruit.com/viewforum.php?f=8&sid=7c05a6a928ba537bcb46dc7a526b0e51

Then he needs to use a level translator (there are a bunch around, do a google search for ā€œfritzing part level translatorā€ to find them) to translate the 3.3V signals to and from 5V. If they are input only (not output to the 3.3V interface) it will usually just work as is. Driving a 3.3v input wiith 5V will generally damage the 3.3V part.

Peter

True, for me I normally use BSS138 logic level converter

But only has 2 channels. I mean, theoratically, you can lay out multiple logic levels (just that Iā€™ve never tried doing that before!)

That said, here is my example with BSs138 Logic Level Convertor.

Thermocouple-incomplete.fzz (24.2 KB)

Iā€™s getting late at my side, I can only help you out tomorrow. Good Luck!

Edit: Iā€™m done, hereā€™s my completed sketch
Thermocouple-improved.fzz (51.9 KB)

Note:

  • Iā€™m a bit busy this week, so I did not complete the schematic view
  • Since the arduino is reading the thermocouple sensor, I think data is being transferred from the module to the arduino (i.e. 3.3V to 5V). If Iā€™m wrong just let me know, I can fix the sketch. It is not to difficult to fix.

Edit 2:

Goodness Gracious, I almost forgot to put in 2 thermocouples
Thermocouple-completed.fzz (53.2 KB)

Hello thanks for help

still have questions if i will use TXSO108e logic converter which has 8 channel so it means for my applications i need only 2 module of this right ? .

and as you designed the sketch in which why you connected 3VO not vin ? .

Well I usually connect my wires to 3.3V (and not VIN) to my 3.3V electronics, so I applied the same logic and connected it to the 3.3V pin

I suppose so

Do you need the Fritzing sketch with the TXSO108e logic converter? If so I can create one (just that Iā€™m busy now but I will be able to complete by the end of this week)

i am going to use this

Aihasd 10pcs 4 Channel IIC I2C Logic Level Logic Level Converter Bi-Directional Module 3.3V to 5V Shifter for Arduino : Amazon.de: Electronics & Photo if i will phase problem then i will let you know thanks

The Fritzing part here

should do for this module.

Peter

79b582844704aed86ca8c74183f0565c0c5e04e4_2_690x261

in this example used this logic level controller where i think connection 5 v at HV and 3.3 v at LV and from max 31855 spi pins throgh TXI at lower vvoltage side channel . i mean in this above photo where mentioned red color line .

so my question is i am using this logic converter which has following pins HV GND LV act same as above example here also i have to connect spi pins from max31855 to the LV1 and Lv4 . i mean i have to do same coonnections as it desiged above wiring ? .

here given LV1 act as TXI , LV2 act as RXO , LV3 as RXO , LV4 as TXI and so on . ?

What logic level convertor are you using? Or is it also BSS138 too, just that it is another variant?

Aihasd 10pcs 4 Channel IIC I2C Logic Level Logic Level Converter Bi-Directional Module 3.3V to 5V Shifter for Arduino : Amazon.de: Electronics & Photo this one

While Iā€™m not entirely sure, I guess itā€™s the same (bi-direction, HV and LV1, 2, 3, 4 are sifnal pins, LV connects to 3.3V Power while HV connects to 5V power