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

[js13ropa]

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.

Thermocouple type K M6 with glass fibre cable

here is my max31855 module details.
MAX31855 Module + K-Type Thermocouple Thermocouple Sensor Temperature ‑200℃~1350℃ Thermocouple Thermometer and Probes

[RAPTOR7762]

@js13ropa

i am attaching my circuit which i made in fritzing . can someone tell me the my connection are right or wrong

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

[js13ropa]

Final Thermocouple.fzz (61.0 KB)

[RAPTOR7762]

Thanks!
I’m halfway done fixing up the schematic. It’s getting ;ate at my side, but I’ll continue tomorrow

[js13ropa]

okay , thanks a lot . it will be a very helpful for me …

[js13ropa]

Hello
is there any update for me ?

thanks a lot

[RAPTOR7762]

Sorry for the late reply😥

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

I’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 here…
https://forums.adafruit.com/viewforum.php?f=8&sid=7c05a6a928ba537bcb46dc7a526b0e51

[vanepp]

@RAPTOR7762

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

Then he needs to use a level translator (there are a bunch around, do a google search for “fritzing part level translator” 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

[RAPTOR7762]

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 I’ve never tried doing that before!)

[RAPTOR7762]

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

Thermocouple-incomplete.fzz (24.2 KB)

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

Edit: I’m done, here’s my completed sketch
Thermocouple-improved.fzz (51.9 KB)

Note:

• I’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 I’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)

[js13ropa]

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 ? .

[RAPTOR7762]

@js13ropa

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

@js13ropa

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 ?

I suppose so

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

[js13ropa]

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

[vanepp]

The Fritzing part here

4 x 5V to 3.3V logic level converter

This is a case where it was easier to fix the problem and then tell you what I did. Schematic here is the main problem (although there are others as well): schematic: group id g7 to id schematic to set the correct layer name Adjust the alignment of the pins to be on a .1 inch grid and reduce the font size to 3.5 to fit the characters correctly (few words for quite a few changes ). bb group id g7 to id breadboard to set the correct layer name. The only problem I know that this…

should do for this module.

Peter

[js13ropa]

@RAPTOR7762

Thermocouple-completed.fzz (53.2 KB)

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 . ?

[RAPTOR7762]

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

[js13ropa]

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

[RAPTOR7762]

While I’m not entirely sure, I guess it’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